feat(alerting): Implement alert-level provider overrides (#929)

* feat(alerting): Implement alert-level provider overrides

Fixes #96

* Fix tests

* Add missing test cases for alerting providers

* feat(alerting): Implement alert-level overrides on all providers

* chore: Add config.yaml to .gitignore

* fix typo in discord provider

* test: Start fixing tests for alerting providers

* test: Fix GitLab tests

* Fix all tests

* test: Improve coverage

* test: Improve coverage

* Rename override to provider-override

* docs: Mention new provider-override config

* test: Improve coverage

* test: Improve coverage

* chore: Rename Alert.OverrideAsBytes to Alert.ProviderOverrideAsBytes

.gitignore

@@ -18,3 +18,4 @@ node_modules
 *.db-wal
 gatus
 config/config.yml
+config.yaml

README.md

@@ -72,8 +72,8 @@ Have any feedback or questions? [Create a discussion](https://github.com/TwiN/ga
     - [Configuring Telegram alerts](#configuring-telegram-alerts)
     - [Configuring Twilio alerts](#configuring-twilio-alerts)
     - [Configuring AWS SES alerts](#configuring-aws-ses-alerts)
-    - [Configuring custom alerts](#configuring-custom-alerts)
     - [Configuring Zulip alerts](#configuring-zulip-alerts)
+    - [Configuring custom alerts](#configuring-custom-alerts)
     - [Setting a default alert](#setting-a-default-alert)
   - [Maintenance](#maintenance)
   - [Security](#security)
@@ -548,14 +548,29 @@ endpoints:
         send-on-resolved: true
 ```
 
+You can also override global provider configuration by using `alerts[].provider-override`, like so:
+```yaml
+endpoints:
+  - name: example
+    url: "https://example.org"
+    conditions:
+      - "[STATUS] == 200"
+    alerts:
+      - type: slack
+        provider-override:
+          webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
+```
+
 > 📝 If an alerting provider is not properly configured, all alerts configured with the provider's type will be
 > ignored.
 
 | Parameter                  | Description                                                                                                                             | Default |
-|:--------------------------|:-----------------------------------------------------------------------------------------------------------------------------------------|:--------|
+|:---------------------------|:----------------------------------------------------------------------------------------------------------------------------------------|:--------|
+| `alerting.awsses`          | Configuration for alerts of type `awsses`. <br />See [Configuring AWS SES alerts](#configuring-aws-ses-alerts).                         | `{}`    |
 | `alerting.custom`          | Configuration for custom actions on failure or alerts. <br />See [Configuring Custom alerts](#configuring-custom-alerts).               | `{}`    |
 | `alerting.discord`         | Configuration for alerts of type `discord`. <br />See [Configuring Discord alerts](#configuring-discord-alerts).                        | `{}`    |
 | `alerting.email`           | Configuration for alerts of type `email`. <br />See [Configuring Email alerts](#configuring-email-alerts).                              | `{}`    |
+| `alerting.gitea`           | Configuration for alerts of type `gitea`. <br />See [Configuring Gitea alerts](#configuring-gitea-alerts).                              | `{}`    |
 | `alerting.github`          | Configuration for alerts of type `github`. <br />See [Configuring GitHub alerts](#configuring-github-alerts).                           | `{}`    |
 | `alerting.gitlab`          | Configuration for alerts of type `gitlab`. <br />See [Configuring GitLab alerts](#configuring-gitlab-alerts).                           | `{}`    |
 | `alerting.googlechat`      | Configuration for alerts of type `googlechat`. <br />See [Configuring Google Chat alerts](#configuring-google-chat-alerts).             | `{}`    |
@@ -573,6 +588,7 @@ endpoints:
 | `alerting.teams-workflows` | Configuration for alerts of type `teams-workflows`. <br />See [Configuring Teams Workflow alerts](#configuring-teams-workflow-alerts).  | `{}`    |
 | `alerting.telegram`        | Configuration for alerts of type `telegram`. <br />See [Configuring Telegram alerts](#configuring-telegram-alerts).                     | `{}`    |
 | `alerting.twilio`          | Settings for alerts of type `twilio`. <br />See [Configuring Twilio alerts](#configuring-twilio-alerts).                                | `{}`    |
+| `alerting.zulip`           | Configuration for alerts of type `zulip`. <br />See [Configuring Zulip alerts](#configuring-zulip-alerts).                              | `{}`    |
 
 
 #### Configuring Discord alerts
@@ -785,14 +801,13 @@ endpoints:
 
 #### Configuring Google Chat alerts
 | Parameter                               | Description                                                                                 | Default       |
-|:----------------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
+|:----------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
 | `alerting.googlechat`                   | Configuration for alerts of type `googlechat`                                               | `{}`          |
 | `alerting.googlechat.webhook-url`       | Google Chat Webhook URL                                                                     | Required `""` |
 | `alerting.googlechat.client`            | Client configuration. <br />See [Client configuration](#client-configuration).              | `{}`          |
 | `alerting.googlechat.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
 | `alerting.googlechat.overrides`         | List of overrides that may be prioritized over the default configuration                    | `[]`          |
 | `alerting.googlechat.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
-| `alerting.googlechat.overrides[].webhook-url` | Google Chat Webhook URL                                                                     | `""`          |
 
 ```yaml
 alerting:
@@ -925,7 +940,6 @@ endpoints:
 | `alerting.mattermost.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
 | `alerting.mattermost.overrides`               | List of overrides that may be prioritized over the default configuration                    | `[]`          |
 | `alerting.mattermost.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
-| `alerting.mattermist.overrides[].webhook-url` | Mattermost Webhook URL                                                                      | `""`          |
 
 ```yaml
 alerting:
@@ -1332,8 +1346,6 @@ Here's an example of what the notifications look like:
 | `alerting.telegram.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                        |
 | `alerting.telegram.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`                       |
 | `alerting.telegram.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`                       |
-| `alerting.telegram.overrides[].token` | Telegram Bot Token for override default value                                              | `""`                       |
-| `alerting.telegram.overrides[].id`    | Telegram User ID for override default value                                                | `""`                       |
 
 ```yaml
 alerting:
@@ -1431,6 +1443,39 @@ If the `access-key-id` and `secret-access-key` are not defined Gatus will fall b
 
 Make sure you have the ability to use `ses:SendEmail`.
 
+#### Configuring Zulip alerts
+| Parameter                          | Description                                                                         | Default       |
+|:-----------------------------------|:------------------------------------------------------------------------------------|:--------------|
+| `alerting.zulip`                   | Configuration for alerts of type `discord`                                          | `{}`          |
+| `alerting.zulip.bot-email`         | Bot Email                                                                           | Required `""` |
+| `alerting.zulip.bot-api-key`       | Bot API key                                                                         | Required `""` |
+| `alerting.zulip.domain`            | Full organization domain (e.g.: yourZulipDomain.zulipchat.com)                      | Required `""` |
+| `alerting.zulip.channel-id`        | The channel ID where Gatus will send the alerts                                     | Required `""` |
+| `alerting.zulip.overrides`         | List of overrides that may be prioritized over the default configuration            | `[]`          |
+| `alerting.zulip.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration | `""`          |
+
+```yaml
+alerting:
+  zulip:
+    bot-email: gatus-bot@some.zulip.org
+    bot-api-key: "********************************"
+    domain: some.zulip.org
+    channel-id: 123456
+
+endpoints:
+  - name: website
+    url: "https://twin.sh/health"
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+      - "[BODY].status == UP"
+      - "[RESPONSE_TIME] < 300"
+    alerts:
+      - type: zulip
+        description: "healthcheck failed"
+        send-on-resolved: true
+```
+
 
 #### Configuring custom alerts
 | Parameter                       | Description                                                                                | Default       |
@@ -1591,42 +1636,6 @@ endpoints:
       - type: pagerduty
 ```
 
-#### Configuring Zulip alerts
-| Parameter                                | Description                                                                         | Default                             |
-|:-----------------------------------------|:------------------------------------------------------------------------------------|:------------------------------------|
-| `alerting.zulip`                         | Configuration for alerts of type `discord`                                          | `{}`                                |
-| `alerting.zulip.bot-email`               | Bot Email                                                                           | Required `""`                       |
-| `alerting.zulip.bot-api-key`             | Bot API key                                                                         | Required `""`                       |
-| `alerting.zulip.domain`                  | Full organization domain (e.g.: yourZulipDomain.zulipchat.com)                      | Required `""`                       |
-| `alerting.zulip.channel-id`              | The channel ID where Gatus will send the alerts                                     | Required `""`                       |
-| `alerting.zulip.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration | `""`                                |
-| `alerting.zulip.overrides[].bot-email`   | .                                                                                   | `""`                                |
-| `alerting.zulip.overrides[].bot-api-key` | .                                                                                   | `""`                                |
-| `alerting.zulip.overrides[].domain`      | .                                                                                   | `""`                                |
-| `alerting.zulip.overrides[].channel-id`  | .                                                                                   | `""`                                |
-
-```yaml
-alerting:
-  zulip:
-    bot-email: gatus-bot@some.zulip.org
-    bot-api-key: "********************************"
-    domain: some.zulip.org
-    channel-id: 123456
-
-endpoints:
-  - name: website
-    url: "https://twin.sh/health"
-    interval: 5m
-    conditions:
-      - "[STATUS] == 200"
-      - "[BODY].status == UP"
-      - "[RESPONSE_TIME] < 300"
-    alerts:
-      - type: zulip
-        description: "healthcheck failed"
-        send-on-resolved: true
-```
-
 
 ### Maintenance
 If you have maintenance windows, you may not want to be annoyed by alerts.

alerting/alert/alert.go

@@ -6,6 +6,9 @@ import (
 	"errors"
 	"strconv"
 	"strings"
+
+	"github.com/TwiN/logr"
+	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -36,13 +39,17 @@ type Alert struct {
 	//
 	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
 	// or not for provider.ParseWithDefaultAlert to work.
-	Description *string `yaml:"description"`
+	Description *string `yaml:"description,omitempty"`
 
 	// SendOnResolved defines whether to send a second notification when the issue has been resolved
 	//
 	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
 	// or not for provider.ParseWithDefaultAlert to work. Use Alert.IsSendingOnResolved() for a non-pointer
-	SendOnResolved *bool `yaml:"send-on-resolved"`
+	SendOnResolved *bool `yaml:"send-on-resolved,omitempty"`
+
+	// ProviderOverride is an optional field that can be used to override the provider's configuration
+	// It is freeform so that it can be used for any provider-specific configuration.
+	ProviderOverride map[string]any `yaml:"provider-override,omitempty"`
 
 	// ResolveKey is an optional field that is used by some providers (i.e. PagerDuty's dedup_key) to resolve
 	// ongoing/triggered incidents
@@ -111,3 +118,11 @@ func (alert *Alert) Checksum() string {
 	)
 	return hex.EncodeToString(hash.Sum(nil))
 }
+
+func (alert *Alert) ProviderOverrideAsBytes() []byte {
+	yamlBytes, err := yaml.Marshal(alert.ProviderOverride)
+	if err != nil {
+		logr.Warnf("[alert.ProviderOverrideAsBytes] Failed to marshal alert override of type=%s as bytes: %v", alert.Type, err)
+	}
+	return yamlBytes
+}

alerting/provider/awsses/awsses.go

@@ -1,30 +1,73 @@
 package awsses
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/logr"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/ses"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	CharSet = "UTF-8"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using AWS Simple Email Service
+var (
-type AlertProvider struct {
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+	ErrMissingFromOrToFields  = errors.New("from and to fields are required")
+	ErrInvalidAWSAuthConfig   = errors.New("either both or neither of access-key-id and secret-access-key must be specified")
+)
+
+type Config struct {
 	AccessKeyID     string `yaml:"access-key-id"`
 	SecretAccessKey string `yaml:"secret-access-key"`
 	Region          string `yaml:"region"`
 
 	From string `yaml:"from"`
 	To   string `yaml:"to"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.From) == 0 || len(cfg.To) == 0 {
+		return ErrMissingFromOrToFields
+	}
+	if !((len(cfg.AccessKeyID) == 0 && len(cfg.SecretAccessKey) == 0) || (len(cfg.AccessKeyID) > 0 && len(cfg.SecretAccessKey) > 0)) {
+		// if both AccessKeyID and SecretAccessKey are specified, we'll use these to authenticate,
+		// otherwise if neither are specified, then we'll fall back on IAM authentication.
+		return ErrInvalidAWSAuthConfig
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.AccessKeyID) > 0 {
+		cfg.AccessKeyID = override.AccessKeyID
+	}
+	if len(override.SecretAccessKey) > 0 {
+		cfg.SecretAccessKey = override.SecretAccessKey
+	}
+	if len(override.Region) > 0 {
+		cfg.Region = override.Region
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using AWS Simple Email Service
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -36,35 +79,36 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	To    string `yaml:"to"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.To) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	// if both AccessKeyID and SecretAccessKey are specified, we'll use these to authenticate,
+	return provider.DefaultConfig.Validate()
-	// otherwise if neither are specified, then we'll fall back on IAM authentication.
-	return len(provider.From) > 0 && len(provider.To) > 0 &&
-		((len(provider.AccessKeyID) == 0 && len(provider.SecretAccessKey) == 0) || (len(provider.AccessKeyID) > 0 && len(provider.SecretAccessKey) > 0))
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	sess, err := provider.createSession()
+	cfg, err := provider.GetConfig(ep.Group, alert)
 	if err != nil {
 		return err
 	}
-	svc := ses.New(sess)
+	awsSession, err := provider.createSession(cfg)
+	if err != nil {
+		return err
+	}
+	svc := ses.New(awsSession)
 	subject, body := provider.buildMessageSubjectAndBody(ep, alert, result, resolved)
-	emails := strings.Split(provider.getToForGroup(ep.Group), ",")
+	emails := strings.Split(cfg.To, ",")
 
 	input := &ses.SendEmailInput{
 		Destination: &ses.Destination{
@@ -82,26 +126,24 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 				Data:    aws.String(subject),
 			},
 		},
-		Source: aws.String(provider.From),
+		Source: aws.String(cfg.From),
 	}
-	_, err = svc.SendEmail(input)
+	if _, err = svc.SendEmail(input); err != nil {
-
-	if err != nil {
 		if aerr, ok := err.(awserr.Error); ok {
 			switch aerr.Code() {
 			case ses.ErrCodeMessageRejected:
-				fmt.Println(ses.ErrCodeMessageRejected, aerr.Error())
+				logr.Error(ses.ErrCodeMessageRejected + ": " + aerr.Error())
 			case ses.ErrCodeMailFromDomainNotVerifiedException:
-				fmt.Println(ses.ErrCodeMailFromDomainNotVerifiedException, aerr.Error())
+				logr.Error(ses.ErrCodeMailFromDomainNotVerifiedException + ": " + aerr.Error())
 			case ses.ErrCodeConfigurationSetDoesNotExistException:
-				fmt.Println(ses.ErrCodeConfigurationSetDoesNotExistException, aerr.Error())
+				logr.Error(ses.ErrCodeConfigurationSetDoesNotExistException + ": " + aerr.Error())
 			default:
-				fmt.Println(aerr.Error())
+				logr.Error(aerr.Error())
 			}
 		} else {
 			// Print the error, cast err to awserr.Error to get the Code and
 			// Message from an error.
-			fmt.Println(err.Error())
+			logr.Error(err.Error())
 		}
 
 		return err
@@ -109,6 +151,16 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return nil
 }
 
+func (provider *AlertProvider) createSession(cfg *Config) (*session.Session, error) {
+	awsConfig := &aws.Config{
+		Region: aws.String(cfg.Region),
+	}
+	if len(cfg.AccessKeyID) > 0 && len(cfg.SecretAccessKey) > 0 {
+		awsConfig.Credentials = credentials.NewStaticCredentials(cfg.AccessKeyID, cfg.SecretAccessKey, "")
+	}
+	return session.NewSession(awsConfig)
+}
+
 // buildMessageSubjectAndBody builds the message subject and body
 func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) (string, string) {
 	var subject, message string
@@ -139,29 +191,38 @@ func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint,
 	return subject, message + description + formattedConditionResults
 }
 
-// getToForGroup returns the appropriate email integration to for a given group
-func (provider *AlertProvider) getToForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.To
-			}
-		}
-	}
-	return provider.To
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
-func (provider *AlertProvider) createSession() (*session.Session, error) {
+// GetConfig returns the configuration for the provider with the overrides applied
-	config := &aws.Config{
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
-		Region: aws.String(provider.Region),
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
 			}
-	if len(provider.AccessKeyID) > 0 && len(provider.SecretAccessKey) > 0 {
-		config.Credentials = credentials.NewStaticCredentials(provider.AccessKeyID, provider.SecretAccessKey, "")
 		}
-	return session.NewSession(config)
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
 }

alerting/provider/awsses/awsses_test.go

@@ -7,59 +7,61 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	invalidProviderWithOneKey := AlertProvider{From: "from@example.com", To: "to@example.com", AccessKeyID: "1"}
+	invalidProviderWithOneKey := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com", AccessKeyID: "1"}}
-	if invalidProviderWithOneKey.IsValid() {
+	if err := invalidProviderWithOneKey.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{From: "from@example.com", To: "to@example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
-	validProviderWithKeys := AlertProvider{From: "from@example.com", To: "to@example.com", AccessKeyID: "1", SecretAccessKey: "1"}
+	validProviderWithKeys := AlertProvider{DefaultConfig: Config{From: "from@example.com", To: "to@example.com", AccessKeyID: "1", SecretAccessKey: "1"}}
-	if !validProviderWithKeys.IsValid() {
+	if err := validProviderWithKeys.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
+				Config: Config{To: "to@example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "",
+				Config: Config{To: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{
 			From: "from@example.com",
 			To:   "to@example.com",
+		},
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
+				Config: Config{To: "to@example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -124,64 +126,124 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getToForGroup(t *testing.T) {
+func TestAlertProvider_getConfigWithOverrides(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
 					To:   "to@example.com",
+				},
 				Overrides: nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
 					To:   "to@example.com",
+				},
 				Overrides: nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
 					To:   "to@example.com",
+				},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						To:    "to01@example.com",
+						Config: Config{To: "groupto@example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
 					To:   "to@example.com",
+				},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						To:    "to01@example.com",
+						Config: Config{To: "groupto@example.com", SecretAccessKey: "wow", AccessKeyID: "noway"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to01@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "groupto@example.com", SecretAccessKey: "wow", AccessKeyID: "noway"},
+		},
+		{
+			Name: "provider-with-override-specify-group-but-alert-override-should-override-group-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					From: "from@example.com",
+					To:   "to@example.com",
+				},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{From: "from@example.com", To: "groupto@example.com", SecretAccessKey: "sekrit"},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{
+				ProviderOverride: map[string]any{
+					"to":            "alertto@example.com",
+					"access-key-id": 123,
+				},
+			},
+			ExpectedOutput: Config{To: "alertto@example.com", From: "from@example.com", AccessKeyID: "123", SecretAccessKey: "sekrit"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getToForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected From to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected To to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			if got.AccessKeyID != scenario.ExpectedOutput.AccessKeyID {
+				t.Errorf("expected AccessKeyID to be %s, got %s", scenario.ExpectedOutput.AccessKeyID, got.AccessKeyID)
+			}
+			if got.SecretAccessKey != scenario.ExpectedOutput.SecretAccessKey {
+				t.Errorf("expected SecretAccessKey to be %s, got %s", scenario.ExpectedOutput.SecretAccessKey, got.SecretAccessKey)
+			}
+			if got.Region != scenario.ExpectedOutput.Region {
+				t.Errorf("expected Region to be %s, got %s", scenario.ExpectedOutput.Region, got.Region)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/custom/custom.go

@@ -2,6 +2,7 @@ package custom
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,11 +11,14 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using a custom HTTP request
+var (
-// Technically, all alert providers should be reachable using the custom alert provider
+	ErrURLNotSet = errors.New("url not set")
-type AlertProvider struct {
+)
+
+type Config struct {
 	URL          string                       `yaml:"url"`
 	Method       string                       `yaml:"method,omitempty"`
 	Body         string                       `yaml:"body,omitempty"`
@@ -23,66 +27,66 @@ type AlertProvider struct {
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
 	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		return ErrURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if len(override.Method) > 0 {
+		cfg.Method = override.Method
+	}
+	if len(override.Body) > 0 {
+		cfg.Body = override.Body
+	}
+	if len(override.Headers) > 0 {
+		cfg.Headers = override.Headers
+	}
+	if len(override.Placeholders) > 0 {
+		cfg.Placeholders = override.Placeholders
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using a custom HTTP request
+// Technically, all alert providers should be reachable using the custom alert provider
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Override is a case under which the default integration is overridden
-func (provider *AlertProvider) IsValid() bool {
+type Override struct {
-	if provider.ClientConfig == nil {
+	Group  string `yaml:"group"`
-		provider.ClientConfig = client.GetDefaultConfig()
+	Config `yaml:",inline"`
-	}
-	return len(provider.URL) > 0 && provider.ClientConfig != nil
 }
 
-// GetAlertStatePlaceholderValue returns the Placeholder value for ALERT_TRIGGERED_OR_RESOLVED if configured
+// Validate the provider's configuration
-func (provider *AlertProvider) GetAlertStatePlaceholderValue(resolved bool) string {
+func (provider *AlertProvider) Validate() error {
-	status := "TRIGGERED"
+	return provider.DefaultConfig.Validate()
-	if resolved {
-		status = "RESOLVED"
-	}
-	if _, ok := provider.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"]; ok {
-		if val, ok := provider.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"][status]; ok {
-			return val
-		}
-	}
-	return status
-}
-
-func (provider *AlertProvider) buildHTTPRequest(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) *http.Request {
-	body, url, method := provider.Body, provider.URL, provider.Method
-	body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alert.GetDescription())
-	url = strings.ReplaceAll(url, "[ALERT_DESCRIPTION]", alert.GetDescription())
-	body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", ep.Name)
-	url = strings.ReplaceAll(url, "[ENDPOINT_NAME]", ep.Name)
-	body = strings.ReplaceAll(body, "[ENDPOINT_GROUP]", ep.Group)
-	url = strings.ReplaceAll(url, "[ENDPOINT_GROUP]", ep.Group)
-	body = strings.ReplaceAll(body, "[ENDPOINT_URL]", ep.URL)
-	url = strings.ReplaceAll(url, "[ENDPOINT_URL]", ep.URL)
-	body = strings.ReplaceAll(body, "[RESULT_ERRORS]", strings.Join(result.Errors, ","))
-	url = strings.ReplaceAll(url, "[RESULT_ERRORS]", strings.Join(result.Errors, ","))
-	if resolved {
-		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
-		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
-	} else {
-		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-	}
-	if len(method) == 0 {
-		method = http.MethodGet
-	}
-	bodyBuffer := bytes.NewBuffer([]byte(body))
-	request, _ := http.NewRequest(method, url, bodyBuffer)
-	for k, v := range provider.Headers {
-		request.Header.Set(k, v)
-	}
-	return request
 }
 
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	request := provider.buildHTTPRequest(ep, alert, result, resolved)
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	if err != nil {
+		return err
+	}
+	request := provider.buildHTTPRequest(cfg, ep, alert, result, resolved)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -94,7 +98,82 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return err
 }
 
+func (provider *AlertProvider) buildHTTPRequest(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) *http.Request {
+	body, url, method := cfg.Body, cfg.URL, cfg.Method
+	body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alert.GetDescription())
+	url = strings.ReplaceAll(url, "[ALERT_DESCRIPTION]", alert.GetDescription())
+	body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", ep.Name)
+	url = strings.ReplaceAll(url, "[ENDPOINT_NAME]", ep.Name)
+	body = strings.ReplaceAll(body, "[ENDPOINT_GROUP]", ep.Group)
+	url = strings.ReplaceAll(url, "[ENDPOINT_GROUP]", ep.Group)
+	body = strings.ReplaceAll(body, "[ENDPOINT_URL]", ep.URL)
+	url = strings.ReplaceAll(url, "[ENDPOINT_URL]", ep.URL)
+	body = strings.ReplaceAll(body, "[RESULT_ERRORS]", strings.Join(result.Errors, ","))
+	url = strings.ReplaceAll(url, "[RESULT_ERRORS]", strings.Join(result.Errors, ","))
+	if resolved {
+		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, true))
+	} else {
+		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, false))
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(cfg, false))
+	}
+	if len(method) == 0 {
+		method = http.MethodGet
+	}
+	bodyBuffer := bytes.NewBuffer([]byte(body))
+	request, _ := http.NewRequest(method, url, bodyBuffer)
+	for k, v := range cfg.Headers {
+		request.Header.Set(k, v)
+	}
+	return request
+}
+
+// GetAlertStatePlaceholderValue returns the Placeholder value for ALERT_TRIGGERED_OR_RESOLVED if configured
+func (provider *AlertProvider) GetAlertStatePlaceholderValue(cfg *Config, resolved bool) string {
+	status := "TRIGGERED"
+	if resolved {
+		status = "RESOLVED"
+	}
+	if _, ok := cfg.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"]; ok {
+		if val, ok := cfg.Placeholders["ALERT_TRIGGERED_OR_RESOLVED"][status]; ok {
+			return val
+		}
+	}
+	return status
+}
+
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/custom/custom_test.go

@@ -12,24 +12,18 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	t.Run("invalid-provider", func(t *testing.T) {
-		invalidProvider := AlertProvider{URL: ""}
+		invalidProvider := AlertProvider{DefaultConfig: Config{URL: ""}}
-		if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
 	})
 	t.Run("valid-provider", func(t *testing.T) {
-		validProvider := AlertProvider{URL: "https://example.com"}
+		validProvider := AlertProvider{DefaultConfig: Config{URL: "https://example.com"}}
-		if validProvider.ClientConfig != nil {
+		if err := validProvider.Validate(); err != nil {
-			t.Error("provider client config should have been nil prior to IsValid() being executed")
-		}
-		if !validProvider.IsValid() {
 			t.Error("provider should've been valid")
 		}
-		if validProvider.ClientConfig == nil {
-			t.Error("provider client config should have been set after IsValid() was executed")
-		}
 	})
 }
 
@@ -47,7 +41,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -57,7 +51,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -67,7 +61,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -77,7 +71,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{URL: "https://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -111,9 +105,11 @@ func TestAlertProvider_Send(t *testing.T) {
 }
 
 func TestAlertProvider_buildHTTPRequest(t *testing.T) {
-	customAlertProvider := &AlertProvider{
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
 			URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]",
 			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED]",
+		},
 	}
 	alertDescription := "alert-description"
 	scenarios := []struct {
@@ -123,13 +119,13 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 		ExpectedBody  string
 	}{
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      true,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=RESOLVED&description=alert-description&url=https://example.com",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,RESOLVED",
 		},
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      false,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED",
@@ -137,7 +133,8 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(fmt.Sprintf("resolved-%v-with-default-placeholders", scenario.Resolved), func(t *testing.T) {
-			request := customAlertProvider.buildHTTPRequest(
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group", URL: "https://example.com"},
 				&alert.Alert{Description: &alertDescription},
 				&endpoint.Result{Errors: []string{}},
@@ -155,9 +152,11 @@ func TestAlertProvider_buildHTTPRequest(t *testing.T) {
 }
 
 func TestAlertProviderWithResultErrors_buildHTTPRequest(t *testing.T) {
-	customAlertWithErrorsProvider := &AlertProvider{
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
 			URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]&error=[RESULT_ERRORS]",
 			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED],[RESULT_ERRORS]",
+		},
 	}
 	alertDescription := "alert-description"
 	scenarios := []struct {
@@ -168,13 +167,13 @@ func TestAlertProviderWithResultErrors_buildHTTPRequest(t *testing.T) {
 		Errors        []string
 	}{
 		{
-			AlertProvider: customAlertWithErrorsProvider,
+			AlertProvider: alertProvider,
 			Resolved:      true,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=RESOLVED&description=alert-description&url=https://example.com&error=",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,RESOLVED,",
 		},
 		{
-			AlertProvider: customAlertWithErrorsProvider,
+			AlertProvider: alertProvider,
 			Resolved:      false,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com&error=error1,error2",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED,error1,error2",
@@ -183,7 +182,8 @@ func TestAlertProviderWithResultErrors_buildHTTPRequest(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(fmt.Sprintf("resolved-%v-with-default-placeholders-and-result-errors", scenario.Resolved), func(t *testing.T) {
-			request := customAlertWithErrorsProvider.buildHTTPRequest(
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group", URL: "https://example.com"},
 				&alert.Alert{Description: &alertDescription},
 				&endpoint.Result{Errors: scenario.Errors},
@@ -201,7 +201,8 @@ func TestAlertProviderWithResultErrors_buildHTTPRequest(t *testing.T) {
 }
 
 func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
-	customAlertProvider := &AlertProvider{
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
 			URL:     "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
 			Body:    "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
 			Headers: nil,
@@ -211,6 +212,7 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 					"TRIGGERED": "boom",
 				},
 			},
+		},
 	}
 	alertDescription := "alert-description"
 	scenarios := []struct {
@@ -220,13 +222,13 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 		ExpectedBody  string
 	}{
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      true,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=fixed&description=alert-description",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,fixed",
 		},
 		{
-			AlertProvider: customAlertProvider,
+			AlertProvider: alertProvider,
 			Resolved:      false,
 			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=boom&description=alert-description",
 			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,boom",
@@ -234,7 +236,8 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(fmt.Sprintf("resolved-%v-with-custom-placeholders", scenario.Resolved), func(t *testing.T) {
-			request := customAlertProvider.buildHTTPRequest(
+			request := alertProvider.buildHTTPRequest(
+				&alertProvider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&alert.Alert{Description: &alertDescription},
 				&endpoint.Result{},
@@ -252,15 +255,17 @@ func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
 }
 
 func TestAlertProvider_GetAlertStatePlaceholderValueDefaults(t *testing.T) {
-	customAlertProvider := &AlertProvider{
+	alertProvider := &AlertProvider{
+		DefaultConfig: Config{
 			URL:  "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
 			Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+		},
 	}
-	if customAlertProvider.GetAlertStatePlaceholderValue(true) != "RESOLVED" {
+	if alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, true) != "RESOLVED" {
-		t.Error("expected RESOLVED, got", customAlertProvider.GetAlertStatePlaceholderValue(true))
+		t.Error("expected RESOLVED, got", alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, true))
 	}
-	if customAlertProvider.GetAlertStatePlaceholderValue(false) != "TRIGGERED" {
+	if alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, false) != "TRIGGERED" {
-		t.Error("expected TRIGGERED, got", customAlertProvider.GetAlertStatePlaceholderValue(false))
+		t.Error("expected TRIGGERED, got", alertProvider.GetAlertStatePlaceholderValue(&alertProvider.DefaultConfig, false))
 	}
 }
 
@@ -272,3 +277,119 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com", Body: "default-body"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com", Body: "default-body"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com", Headers: map[string]string{"Cache": "true"}},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://example.com", Headers: map[string]string{"Cache": "true"}},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com", Body: "default-body"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com", Body: "group-body"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "http://group-example.com", Body: "group-body"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"url": "http://alert-example.com", "body": "alert-body"}},
+			ExpectedOutput: Config{URL: "http://alert-example.com", Body: "alert-body"},
+		},
+		{
+			Name: "provider-with-partial-overrides",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{Method: "POST"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"body": "alert-body"}},
+			ExpectedOutput: Config{URL: "http://example.com", Body: "alert-body", Method: "POST"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.URL != scenario.ExpectedOutput.URL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.URL, got.URL)
+			}
+			if got.Body != scenario.ExpectedOutput.Body {
+				t.Errorf("expected body to be %s, got %s", scenario.ExpectedOutput.Body, got.Body)
+			}
+			if got.Headers != nil {
+				for key, value := range scenario.ExpectedOutput.Headers {
+					if got.Headers[key] != value {
+						t.Errorf("expected header %s to be %s, got %s", key, value, got.Headers[key])
+					}
+				}
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/discord/discord.go

@@ -3,6 +3,7 @@ package discord
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,46 +11,73 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Discord
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
-// Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -85,7 +113,7 @@ type Field struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	var colorCode int
 	if resolved {
@@ -110,8 +138,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		description = ":\n> " + alertDescription
 	}
 	title := ":helmet_with_white_cross: Gatus"
-	if provider.Title != "" {
+	if cfg.Title != "" {
-		title = provider.Title
+		title = cfg.Title
 	}
 	body := Body{
 		Content: "",
@@ -134,19 +162,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/discord/discord_test.go

@@ -11,50 +11,52 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
+				Config: Config{WebhookURL: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{
 			WebhookURL: "http://example.com",
+		},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -74,7 +76,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -84,7 +86,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -94,7 +96,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -104,7 +106,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -114,7 +116,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-with-modified-title",
-			Provider: AlertProvider{Title: title},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com", Title: title}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -122,6 +124,16 @@ func TestAlertProvider_Send(t *testing.T) {
 			}),
 			ExpectedError: false,
 		},
+		{
+			Name:     "triggered-with-webhook-override",
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3, ProviderOverride: map[string]any{"webhook-url": "http://example01.com"}},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
@@ -175,7 +187,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		},
 		{
 			Name:         "triggered-with-modified-title",
-			Provider:     AlertProvider{Title: title},
+			Provider:     AlertProvider{DefaultConfig: Config{Title: title}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"content\":\"\",\"embeds\":[{\"title\":\"provider-title\",\"description\":\"An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\",\"color\":15158332,\"fields\":[{\"name\":\"Condition results\",\"value\":\":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n:x: - `[BODY] != \\\"\\\"`\\n\",\"inline\":false}]}]}",
@@ -183,7 +195,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		{
 			Name:         "triggered-with-no-conditions",
 			NoConditions: true,
-			Provider:     AlertProvider{Title: title},
+			Provider:     AlertProvider{DefaultConfig: Config{Title: title}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"content\":\"\",\"embeds\":[{\"title\":\"provider-title\",\"description\":\"An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\",\"color\":15158332}]}",
@@ -200,6 +212,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				}
 			}
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -227,64 +240,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/email/email.go

@@ -2,6 +2,7 @@ package email
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"math"
 	"strings"
@@ -10,10 +11,17 @@ import (
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	gomail "gopkg.in/mail.v2"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using SMTP
+var (
-type AlertProvider struct {
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+	ErrMissingFromOrToFields  = errors.New("from and to fields are required")
+	ErrInvalidPort            = errors.New("port must be between 1 and 65535 inclusively")
+	ErrMissingHost            = errors.New("host is required")
+)
+
+type Config struct {
 	From     string `yaml:"from"`
 	Username string `yaml:"username"`
 	Password string `yaml:"password"`
@@ -23,6 +31,48 @@ type AlertProvider struct {
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
 	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.From) == 0 || len(cfg.To) == 0 {
+		return ErrMissingFromOrToFields
+	}
+	if cfg.Port < 1 || cfg.Port > math.MaxUint16 {
+		return ErrInvalidPort
+	}
+	if len(cfg.Host) == 0 {
+		return ErrMissingHost
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.Username) > 0 {
+		cfg.Username = override.Username
+	}
+	if len(override.Password) > 0 {
+		cfg.Password = override.Password
+	}
+	if len(override.Host) > 0 {
+		cfg.Host = override.Host
+	}
+	if override.Port > 0 {
+		cfg.Port = override.Port
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using SMTP
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -34,53 +84,56 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	To    string `yaml:"to"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.To) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-
+	return provider.DefaultConfig.Validate()
-	return len(provider.From) > 0 && len(provider.Host) > 0 && len(provider.To) > 0 && provider.Port > 0 && provider.Port < math.MaxUint16
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	var username string
-	if len(provider.Username) > 0 {
+	if len(cfg.Username) > 0 {
-		username = provider.Username
+		username = cfg.Username
 	} else {
-		username = provider.From
+		username = cfg.From
 	}
 	subject, body := provider.buildMessageSubjectAndBody(ep, alert, result, resolved)
 	m := gomail.NewMessage()
-	m.SetHeader("From", provider.From)
+	m.SetHeader("From", cfg.From)
-	m.SetHeader("To", strings.Split(provider.getToForGroup(ep.Group), ",")...)
+	m.SetHeader("To", strings.Split(cfg.To, ",")...)
 	m.SetHeader("Subject", subject)
 	m.SetBody("text/plain", body)
 	var d *gomail.Dialer
-	if len(provider.Password) == 0 {
+	if len(cfg.Password) == 0 {
 		// Get the domain in the From address
 		localName := "localhost"
-		fromParts := strings.Split(provider.From, `@`)
+		fromParts := strings.Split(cfg.From, `@`)
 		if len(fromParts) == 2 {
 			localName = fromParts[1]
 		}
 		// Create a dialer with no authentication
-		d = &gomail.Dialer{Host: provider.Host, Port: provider.Port, LocalName: localName}
+		d = &gomail.Dialer{Host: cfg.Host, Port: cfg.Port, LocalName: localName}
 	} else {
 		// Create an authenticated dialer
-		d = gomail.NewDialer(provider.Host, provider.Port, username, provider.Password)
+		d = gomail.NewDialer(cfg.Host, cfg.Port, username, cfg.Password)
 	}
-	if provider.ClientConfig != nil && provider.ClientConfig.Insecure {
+	if cfg.ClientConfig != nil && cfg.ClientConfig.Insecure {
 		d.TLSConfig = &tls.Config{InsecureSkipVerify: true}
 	}
 	return d.DialAndSend(m)
@@ -116,19 +169,38 @@ func (provider *AlertProvider) buildMessageSubjectAndBody(ep *endpoint.Endpoint,
 	return subject, message + description + formattedConditionResults
 }
 
-// getToForGroup returns the appropriate email integration to for a given group
-func (provider *AlertProvider) getToForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.To
-			}
-		}
-	}
-	return provider.To
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/email/email_test.go

@@ -7,61 +7,63 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{From: "from@example.com", Password: "password", Host: "smtp.gmail.com", Port: 587, To: "to@example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", Password: "password", Host: "smtp.gmail.com", Port: 587, To: "to@example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithNoCredentials(t *testing.T) {
+func TestAlertProvider_ValidateWithNoCredentials(t *testing.T) {
-	validProvider := AlertProvider{From: "from@example.com", Host: "smtp-relay.gmail.com", Port: 587, To: "to@example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{From: "from@example.com", Host: "smtp-relay.gmail.com", Port: 587, To: "to@example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
+				Config: Config{To: "to@example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				To:    "",
+				Config: Config{To: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{
 			From:     "from@example.com",
 			Password: "password",
 			Host:     "smtp.gmail.com",
 			Port:     587,
 			To:       "to@example.com",
+		},
 		Overrides: []Override{
 			{
-				To:    "to@example.com",
+				Config: Config{To: "to@example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -126,64 +128,104 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getToForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				To:        "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						To:    "to01@example.com",
+						Config: Config{To: "to01@example.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "to@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				To: "to@example.com",
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						To:    "to01@example.com",
+						Config: Config{To: "group-to@example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "to01@example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{From: "from@example.com", To: "group-to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{From: "from@example.com", To: "to@example.com", Host: "smtp.gmail.com", Port: 587, Password: "password"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{To: "group-to@example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"to": "alert-to@example.com", "host": "smtp.example.com", "port": 588, "password": "hunter2"}},
+			ExpectedOutput: Config{From: "from@example.com", To: "alert-to@example.com", Host: "smtp.example.com", Port: 588, Password: "hunter2"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getToForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected from to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			if got.Host != scenario.ExpectedOutput.Host {
+				t.Errorf("expected host to be %s, got %s", scenario.ExpectedOutput.Host, got.Host)
+			}
+			if got.Port != scenario.ExpectedOutput.Port {
+				t.Errorf("expected port to be %d, got %d", scenario.ExpectedOutput.Port, got.Port)
+			}
+			if got.Password != scenario.ExpectedOutput.Password {
+				t.Errorf("expected password to be %s, got %s", scenario.ExpectedOutput.Password, got.Password)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/gitea/gitea.go

@@ -2,6 +2,7 @@ package gitea
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -11,55 +12,56 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Discord
+var (
-type AlertProvider struct {
+	ErrRepositoryURLNotSet  = errors.New("repository-url not set")
+	ErrInvalidRepositoryURL = errors.New("invalid repository-url")
+	ErrTokenNotSet          = errors.New("token not set")
+)
+
+type Config struct {
 	RepositoryURL string   `yaml:"repository-url"`      // The URL of the Gitea repository to create issues in
 	Token         string   `yaml:"token"`               // Token requires at least RW on issues and RO on metadata
-
+	Assignees     []string `yaml:"assignees,omitempty"` // Assignees is a list of users to assign the issue to
-	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
-
-	// Assignees is a list of users to assign the issue to
-	Assignees []string `yaml:"assignees,omitempty"`
 
 	username        string
 	repositoryOwner string
 	repositoryName  string
 	giteaClient     *gitea.Client
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+func (cfg *Config) Validate() error {
-func (provider *AlertProvider) IsValid() bool {
+	if len(cfg.RepositoryURL) == 0 {
-	if provider.ClientConfig == nil {
+		return ErrRepositoryURLNotSet
-		provider.ClientConfig = client.GetDefaultConfig()
 	}
-
+	if len(cfg.Token) == 0 {
-	if len(provider.Token) == 0 || len(provider.RepositoryURL) == 0 {
+		return ErrTokenNotSet
-		return false
 	}
 	// Validate format of the repository URL
-	repositoryURL, err := url.Parse(provider.RepositoryURL)
+	repositoryURL, err := url.Parse(cfg.RepositoryURL)
 	if err != nil {
-		return false
+		return err
 	}
 	baseURL := repositoryURL.Scheme + "://" + repositoryURL.Host
 	pathParts := strings.Split(repositoryURL.Path, "/")
 	if len(pathParts) != 3 {
-		return false
+		return ErrInvalidRepositoryURL
 	}
-	provider.repositoryOwner = pathParts[1]
+	if cfg.repositoryOwner == pathParts[1] && cfg.repositoryName == pathParts[2] && cfg.giteaClient != nil {
-	provider.repositoryName = pathParts[2]
+		// Already validated, let's skip the rest of the validation to avoid unnecessary API calls
-
+		return nil
+	}
+	cfg.repositoryOwner = pathParts[1]
+	cfg.repositoryName = pathParts[2]
 	opts := []gitea.ClientOption{
-		gitea.SetToken(provider.Token),
+		gitea.SetToken(cfg.Token),
 	}
-
+	if cfg.ClientConfig != nil && cfg.ClientConfig.Insecure {
-	if provider.ClientConfig != nil && provider.ClientConfig.Insecure {
 		// add new http client for skip verify
 		httpClient := &http.Client{
 			Transport: &http.Transport{
@@ -68,34 +70,62 @@ func (provider *AlertProvider) IsValid() bool {
 		}
 		opts = append(opts, gitea.SetHTTPClient(httpClient))
 	}
-
+	cfg.giteaClient, err = gitea.NewClient(baseURL, opts...)
-	provider.giteaClient, err = gitea.NewClient(baseURL, opts...)
 	if err != nil {
-		return false
+		return err
+	}
+	user, _, err := cfg.giteaClient.GetMyUserInfo()
+	if err != nil {
+		return err
+	}
+	cfg.username = user.UserName
+	return nil
 }
 
-	user, _, err := provider.giteaClient.GetMyUserInfo()
+func (cfg *Config) Merge(override *Config) {
-	if err != nil {
+	if override.ClientConfig != nil {
-		return false
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.RepositoryURL) > 0 {
+		cfg.RepositoryURL = override.RepositoryURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.Assignees) > 0 {
+		cfg.Assignees = override.Assignees
+	}
 }
 
-	provider.username = user.UserName
+// AlertProvider is the configuration necessary for sending an alert using Discord
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
-	return true
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	title := "alert(gatus): " + ep.DisplayName()
 	if !resolved {
-		_, _, err := provider.giteaClient.CreateIssue(
+		_, _, err = cfg.giteaClient.CreateIssue(
-			provider.repositoryOwner,
+			cfg.repositoryOwner,
-			provider.repositoryName,
+			cfg.repositoryName,
 			gitea.CreateIssueOption{
 				Title:     title,
 				Body:      provider.buildIssueBody(ep, alert, result),
-				Assignees: provider.Assignees,
+				Assignees: cfg.Assignees,
 			},
 		)
 		if err != nil {
@@ -103,13 +133,12 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 		}
 		return nil
 	}
-
+	issues, _, err := cfg.giteaClient.ListRepoIssues(
-	issues, _, err := provider.giteaClient.ListRepoIssues(
+		cfg.repositoryOwner,
-		provider.repositoryOwner,
+		cfg.repositoryName,
-		provider.repositoryName,
 		gitea.ListIssueOption{
 			State:     gitea.StateOpen,
-			CreatedBy: provider.username,
+			CreatedBy: cfg.username,
 			ListOptions: gitea.ListOptions{
 				Page: 100,
 			},
@@ -118,13 +147,12 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	if err != nil {
 		return fmt.Errorf("failed to list issues: %w", err)
 	}
-
 	for _, issue := range issues {
 		if issue.Title == title {
 			stateClosed := gitea.StateClosed
-			_, _, err = provider.giteaClient.EditIssue(
+			_, _, err = cfg.giteaClient.EditIssue(
-				provider.repositoryOwner,
+				cfg.repositoryOwner,
-				provider.repositoryName,
+				cfg.repositoryName,
 				issue.ID,
 				gitea.EditIssueOption{
 					State: &stateClosed,
@@ -165,3 +193,25 @@ func (provider *AlertProvider) buildIssueBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gitea/gitea_test.go

@@ -12,42 +12,46 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		Name          string
 		Provider      AlertProvider
-		Expected bool
+		ExpectedError bool
 	}{
 		{
 			Name:          "invalid",
-			Provider: AlertProvider{RepositoryURL: "", Token: ""},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "", Token: ""}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "invalid-token",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "missing-repository-name",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.com/TwiN", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "enterprise-client",
-			Provider: AlertProvider{RepositoryURL: "https://gitea.example.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.example.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: false,
 		},
 		{
 			Name:          "invalid-url",
-			Provider: AlertProvider{RepositoryURL: "gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "gitea.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
+			err := scenario.Provider.Validate()
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -67,14 +71,14 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -82,9 +86,13 @@ func TestAlertProvider_Send(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			scenario.Provider.giteaClient, _ = gitea.NewClient("https://gitea.com")
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
+			}
+			cfg.giteaClient, _ = gitea.NewClient("https://gitea.com")
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
-			err := scenario.Provider.Send(
+			err = scenario.Provider.Send(
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -167,3 +175,55 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://gitea.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://gitea.com/TwiN/alert-test", "token": "54321", "assignees": []string{"TwiN"}}},
+			ExpectedOutput: Config{RepositoryURL: "https://gitea.com/TwiN/alert-test", Token: "54321", Assignees: []string{"TwiN"}},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.RepositoryURL != scenario.ExpectedOutput.RepositoryURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.RepositoryURL, got.RepositoryURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			if len(got.Assignees) != len(scenario.ExpectedOutput.Assignees) {
+				t.Errorf("expected %d assignees, got %d", len(scenario.ExpectedOutput.Assignees), len(got.Assignees))
+			}
+			for i, assignee := range got.Assignees {
+				if assignee != scenario.ExpectedOutput.Assignees[i] {
+					t.Errorf("expected assignee %s, got %s", scenario.ExpectedOutput.Assignees[i], assignee)
+				}
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil && !strings.Contains(err.Error(), "user does not exist") {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/github/github.go

@@ -2,6 +2,7 @@ package github
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/url"
 	"strings"
@@ -11,69 +12,104 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/google/go-github/v48/github"
 	"golang.org/x/oauth2"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Discord
+var (
-type AlertProvider struct {
+	ErrRepositoryURLNotSet  = errors.New("repository-url not set")
+	ErrInvalidRepositoryURL = errors.New("invalid repository-url")
+	ErrTokenNotSet          = errors.New("token not set")
+)
+
+type Config struct {
 	RepositoryURL string `yaml:"repository-url"` // The URL of the GitHub repository to create issues in
 	Token         string `yaml:"token"`          // Token requires at least RW on issues and RO on metadata
 
-	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
 	username        string
 	repositoryOwner string
 	repositoryName  string
 	githubClient    *github.Client
 }
 
-// IsValid returns whether the provider's configuration is valid
+func (cfg *Config) Validate() error {
-func (provider *AlertProvider) IsValid() bool {
+	if len(cfg.RepositoryURL) == 0 {
-	if len(provider.Token) == 0 || len(provider.RepositoryURL) == 0 {
+		return ErrRepositoryURLNotSet
-		return false
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
 	}
 	// Validate format of the repository URL
-	repositoryURL, err := url.Parse(provider.RepositoryURL)
+	repositoryURL, err := url.Parse(cfg.RepositoryURL)
 	if err != nil {
-		return false
+		return err
 	}
 	baseURL := repositoryURL.Scheme + "://" + repositoryURL.Host
 	pathParts := strings.Split(repositoryURL.Path, "/")
 	if len(pathParts) != 3 {
-		return false
+		return ErrInvalidRepositoryURL
 	}
-	provider.repositoryOwner = pathParts[1]
+	if cfg.repositoryOwner == pathParts[1] && cfg.repositoryName == pathParts[2] && cfg.githubClient != nil {
-	provider.repositoryName = pathParts[2]
+		// Already validated, let's skip the rest of the validation to avoid unnecessary API calls
+		return nil
+	}
+	cfg.repositoryOwner = pathParts[1]
+	cfg.repositoryName = pathParts[2]
 	// Create oauth2 HTTP client with GitHub token
 	httpClientWithStaticTokenSource := oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(&oauth2.Token{
-		AccessToken: provider.Token,
+		AccessToken: cfg.Token,
 	}))
 	// Create GitHub client
 	if baseURL == "https://github.com" {
-		provider.githubClient = github.NewClient(httpClientWithStaticTokenSource)
+		cfg.githubClient = github.NewClient(httpClientWithStaticTokenSource)
 	} else {
-		provider.githubClient, err = github.NewEnterpriseClient(baseURL, baseURL, httpClientWithStaticTokenSource)
+		cfg.githubClient, err = github.NewEnterpriseClient(baseURL, baseURL, httpClientWithStaticTokenSource)
 		if err != nil {
-			return false
+			return fmt.Errorf("failed to create enterprise GitHub client: %w", err)
 		}
 	}
 	// Retrieve the username once to validate that the token is valid
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
-	user, _, err := provider.githubClient.Users.Get(ctx, "")
+	user, _, err := cfg.githubClient.Users.Get(ctx, "")
 	if err != nil {
-		return false
+		return fmt.Errorf("failed to retrieve GitHub user: %w", err)
 	}
-	provider.username = *user.Login
+	cfg.username = *user.Login
-	return true
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.RepositoryURL) > 0 {
+		cfg.RepositoryURL = override.RepositoryURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Discord
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	return provider.DefaultConfig.Validate()
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	title := "alert(gatus): " + ep.DisplayName()
 	if !resolved {
-		_, _, err := provider.githubClient.Issues.Create(context.Background(), provider.repositoryOwner, provider.repositoryName, &github.IssueRequest{
+		_, _, err := cfg.githubClient.Issues.Create(context.Background(), cfg.repositoryOwner, cfg.repositoryName, &github.IssueRequest{
 			Title: github.String(title),
 			Body:  github.String(provider.buildIssueBody(ep, alert, result)),
 		})
@@ -81,9 +117,9 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 			return fmt.Errorf("failed to create issue: %w", err)
 		}
 	} else {
-		issues, _, err := provider.githubClient.Issues.ListByRepo(context.Background(), provider.repositoryOwner, provider.repositoryName, &github.IssueListByRepoOptions{
+		issues, _, err := cfg.githubClient.Issues.ListByRepo(context.Background(), cfg.repositoryOwner, cfg.repositoryName, &github.IssueListByRepoOptions{
 			State:       "open",
-			Creator:     provider.username,
+			Creator:     cfg.username,
 			ListOptions: github.ListOptions{PerPage: 100},
 		})
 		if err != nil {
@@ -91,7 +127,7 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 		}
 		for _, issue := range issues {
 			if *issue.Title == title {
-				_, _, err = provider.githubClient.Issues.Edit(context.Background(), provider.repositoryOwner, provider.repositoryName, *issue.Number, &github.IssueRequest{
+				_, _, err = cfg.githubClient.Issues.Edit(context.Background(), cfg.repositoryOwner, cfg.repositoryName, *issue.Number, &github.IssueRequest{
 					State: github.String("closed"),
 				})
 				if err != nil {
@@ -130,3 +166,25 @@ func (provider *AlertProvider) buildIssueBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/github/github_test.go

@@ -12,42 +12,46 @@ import (
 	"github.com/google/go-github/v48/github"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		Name          string
 		Provider      AlertProvider
-		Expected bool
+		ExpectedError bool
 	}{
 		{
 			Name:          "invalid",
-			Provider: AlertProvider{RepositoryURL: "", Token: ""},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "", Token: ""}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "invalid-token",
-			Provider: AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "missing-repository-name",
-			Provider: AlertProvider{RepositoryURL: "https://github.com/TwiN", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "enterprise-client",
-			Provider: AlertProvider{RepositoryURL: "https://github.example.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.example.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "invalid-url",
-			Provider: AlertProvider{RepositoryURL: "github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "github.com/TwiN/test", Token: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
+			err := scenario.Provider.Validate()
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -67,14 +71,14 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -82,9 +86,13 @@ func TestAlertProvider_Send(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			scenario.Provider.githubClient = github.NewClient(nil)
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
+			}
+			cfg.githubClient = github.NewClient(nil)
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
-			err := scenario.Provider.Send(
+			err = scenario.Provider.Send(
 				&endpoint.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -167,3 +175,47 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{RepositoryURL: "https://github.com/TwiN/test", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://github.com/TwiN/alert-test", "token": "54321"}},
+			ExpectedOutput: Config{RepositoryURL: "https://github.com/TwiN/alert-test", Token: "54321"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.RepositoryURL != scenario.ExpectedOutput.RepositoryURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.RepositoryURL, got.RepositoryURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil && !strings.Contains(err.Error(), "failed to retrieve GitHub user") {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/gitlab/gitlab.go

@@ -13,55 +13,97 @@ import (
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/google/uuid"
+	"gopkg.in/yaml.v3"
 )
 
+const (
+	DefaultSeverity       = "critical"
+	DefaultMonitoringTool = "gatus"
+)
+
+var (
+	ErrInvalidWebhookURL      = fmt.Errorf("invalid webhook-url")
+	ErrAuthorizationKeyNotSet = fmt.Errorf("authorization-key not set")
+)
+
+type Config struct {
+	WebhookURL       string `yaml:"webhook-url"`                // The webhook url provided by GitLab
+	AuthorizationKey string `yaml:"authorization-key"`          // The authorization key provided by GitLab
+	Severity         string `yaml:"severity,omitempty"`         // Severity can be one of: critical, high, medium, low, info, unknown. Defaults to critical
+	MonitoringTool   string `yaml:"monitoring-tool,omitempty"`  // MonitoringTool overrides the name sent to gitlab. Defaults to gatus
+	EnvironmentName  string `yaml:"environment-name,omitempty"` // EnvironmentName is the name of the associated GitLab environment. Required to display alerts on a dashboard.
+	Service          string `yaml:"service,omitempty"`          // Service affected. Defaults to the endpoint's display name
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrInvalidWebhookURL
+	} else if _, err := url.Parse(cfg.WebhookURL); err != nil {
+		return ErrInvalidWebhookURL
+	}
+	if len(cfg.AuthorizationKey) == 0 {
+		return ErrAuthorizationKeyNotSet
+	}
+	if len(cfg.Severity) == 0 {
+		cfg.Severity = DefaultSeverity
+	}
+	if len(cfg.MonitoringTool) == 0 {
+		cfg.MonitoringTool = DefaultMonitoringTool
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.AuthorizationKey) > 0 {
+		cfg.AuthorizationKey = override.AuthorizationKey
+	}
+	if len(override.Severity) > 0 {
+		cfg.Severity = override.Severity
+	}
+	if len(override.MonitoringTool) > 0 {
+		cfg.MonitoringTool = override.MonitoringTool
+	}
+	if len(override.EnvironmentName) > 0 {
+		cfg.EnvironmentName = override.EnvironmentName
+	}
+	if len(override.Service) > 0 {
+		cfg.Service = override.Service
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using GitLab
 type AlertProvider struct {
-	WebhookURL       string `yaml:"webhook-url"`       // The webhook url provided by GitLab
+	DefaultConfig Config `yaml:",inline"`
-	AuthorizationKey string `yaml:"authorization-key"` // The authorization key provided by GitLab
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// Severity can be one of: critical, high, medium, low, info, unknown. Defaults to critical
-	Severity string `yaml:"severity,omitempty"`
-
-	// MonitoringTool overrides the name sent to gitlab. Defaults to gatus
-	MonitoringTool string `yaml:"monitoring-tool,omitempty"`
-
-	// EnvironmentName is the name of the associated GitLab environment. Required to display alerts on a dashboard.
-	EnvironmentName string `yaml:"environment-name,omitempty"`
-
-	// Service affected. Defaults to endpoint display name
-	Service string `yaml:"service,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if len(provider.AuthorizationKey) == 0 || len(provider.WebhookURL) == 0 {
+	return provider.DefaultConfig.Validate()
-		return false
-	}
-	// Validate format of the repository URL
-	_, err := url.Parse(provider.WebhookURL)
-	if err != nil {
-		return false
-	}
-	return true
 }
 
 // Send creates an issue in the designed RepositoryURL if the resolved parameter passed is false,
 // or closes the relevant issue(s) if the resolved parameter passed is true.
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	if len(alert.ResolveKey) == 0 {
 		alert.ResolveKey = uuid.NewString()
 	}
-	buffer := bytes.NewBuffer(provider.buildAlertBody(ep, alert, result, resolved))
+	buffer := bytes.NewBuffer(provider.buildAlertBody(cfg, ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.WebhookURL, buffer)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", provider.AuthorizationKey))
+	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", cfg.AuthorizationKey))
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -87,30 +129,20 @@ type AlertBody struct {
 	GitlabEnvironmentName string `json:"gitlab_environment_name,omitempty"` // The name of the associated GitLab environment. Required to display alerts on a dashboard.
 }
 
-func (provider *AlertProvider) monitoringTool() string {
-	if len(provider.MonitoringTool) > 0 {
-		return provider.MonitoringTool
-	}
-	return "gatus"
-}
-
-func (provider *AlertProvider) service(ep *endpoint.Endpoint) string {
-	if len(provider.Service) > 0 {
-		return provider.Service
-	}
-	return ep.DisplayName()
-}
-
 // buildAlertBody builds the body of the alert
-func (provider *AlertProvider) buildAlertBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildAlertBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	service := cfg.Service
+	if len(service) == 0 {
+		service = ep.DisplayName()
+	}
 	body := AlertBody{
-		Title:                 fmt.Sprintf("alert(%s): %s", provider.monitoringTool(), provider.service(ep)),
+		Title:                 fmt.Sprintf("alert(%s): %s", cfg.MonitoringTool, service),
 		StartTime:             result.Timestamp.Format(time.RFC3339),
-		Service:               provider.service(ep),
+		Service:               service,
-		MonitoringTool:        provider.monitoringTool(),
+		MonitoringTool:        cfg.MonitoringTool,
 		Hosts:                 ep.URL,
-		GitlabEnvironmentName: provider.EnvironmentName,
+		GitlabEnvironmentName: cfg.EnvironmentName,
-		Severity:              provider.Severity,
+		Severity:              cfg.Severity,
 		Fingerprint:           alert.ResolveKey,
 	}
 	if resolved {
@@ -148,3 +180,25 @@ func (provider *AlertProvider) buildAlertBody(ep *endpoint.Endpoint, alert *aler
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration (we're returning the cfg here even if there's an error mostly for testing purposes)
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gitlab/gitlab_test.go

@@ -11,37 +11,41 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		Name          string
 		Provider      AlertProvider
-		Expected bool
+		ExpectedError bool
 	}{
 		{
 			Name:          "invalid",
-			Provider: AlertProvider{WebhookURL: "", AuthorizationKey: ""},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "", AuthorizationKey: ""}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "missing-webhook-url",
-			Provider: AlertProvider{WebhookURL: "", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "", AuthorizationKey: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "missing-authorization-key",
-			Provider: AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: ""},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/whatever/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: ""}},
-			Expected: false,
+			ExpectedError: true,
 		},
 		{
 			Name:          "invalid-url",
-			Provider: AlertProvider{WebhookURL: " http://foo.com", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: " http://foo.com", AuthorizationKey: "12345"}},
-			Expected: false,
+			ExpectedError: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			if scenario.Provider.IsValid() != scenario.Expected {
+			err := scenario.Provider.Validate()
-				t.Errorf("expected %t, got %t", scenario.Expected, scenario.Provider.IsValid())
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Error("expected no error, got", err.Error())
 			}
 		})
 	}
@@ -61,7 +65,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:         alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: false,
@@ -71,7 +75,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"},
+			Provider:      AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:         alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: false,
@@ -116,21 +120,26 @@ func TestAlertProvider_buildAlertBody(t *testing.T) {
 		{
 			Name:         "triggered",
 			Endpoint:     endpoint.Endpoint{Name: "endpoint-name", URL: "https://example.org"},
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:        alert.Alert{Description: &firstDescription, FailureThreshold: 3},
-			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\"}",
+			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n\\u003e description-1\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\",\"severity\":\"critical\"}",
 		},
 		{
 			Name:         "no-description",
 			Endpoint:     endpoint.Endpoint{Name: "endpoint-name", URL: "https://example.org"},
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{WebhookURL: "https://gitlab.com/hlidotbe/text/alerts/notify/gatus/xxxxxxxxxxxxxxxx.json", AuthorizationKey: "12345"}},
 			Alert:        alert.Alert{FailureThreshold: 10},
-			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 10 time(s) in a row\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\"}",
+			ExpectedBody: "{\"title\":\"alert(gatus): endpoint-name\",\"description\":\"An alert for *endpoint-name* has been triggered due to having failed 10 time(s) in a row\\n\\n## Condition results\\n- :white_check_mark: - `[CONNECTED] == true`\\n- :x: - `[STATUS] == 200`\\n\",\"start_time\":\"0001-01-01T00:00:00Z\",\"service\":\"endpoint-name\",\"monitoring_tool\":\"gatus\",\"hosts\":\"https://example.org\",\"severity\":\"critical\"}",
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
 			body := scenario.Provider.buildAlertBody(
+				cfg,
 				&scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
@@ -156,3 +165,59 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345", Severity: DefaultSeverity, MonitoringTool: DefaultMonitoringTool},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"repository-url": "https://github.com/TwiN/alert-test", "authorization-key": "54321", "severity": "info", "monitoring-tool": "not-gatus", "environment-name": "prod", "service": "example"}},
+			ExpectedOutput: Config{WebhookURL: "https://github.com/TwiN/test", AuthorizationKey: "54321", Severity: "info", MonitoringTool: "not-gatus", EnvironmentName: "prod", Service: "example"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil && !strings.Contains(err.Error(), "user does not exist") && !strings.Contains(err.Error(), "no such host") {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected repository URL %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			if got.AuthorizationKey != scenario.ExpectedOutput.AuthorizationKey {
+				t.Errorf("expected AuthorizationKey %s, got %s", scenario.ExpectedOutput.AuthorizationKey, got.AuthorizationKey)
+			}
+			if got.Severity != scenario.ExpectedOutput.Severity {
+				t.Errorf("expected Severity %s, got %s", scenario.ExpectedOutput.Severity, got.Severity)
+			}
+			if got.MonitoringTool != scenario.ExpectedOutput.MonitoringTool {
+				t.Errorf("expected MonitoringTool %s, got %s", scenario.ExpectedOutput.MonitoringTool, got.MonitoringTool)
+			}
+			if got.EnvironmentName != scenario.ExpectedOutput.EnvironmentName {
+				t.Errorf("expected EnvironmentName %s, got %s", scenario.ExpectedOutput.EnvironmentName, got.EnvironmentName)
+			}
+			if got.Service != scenario.ExpectedOutput.Service {
+				t.Errorf("expected Service %s, got %s", scenario.ExpectedOutput.Service, got.Service)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/googlechat/googlechat.go

@@ -3,6 +3,7 @@ package googlechat
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,14 +11,38 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL   string         `yaml:"webhook-url"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Google chat
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -29,35 +54,36 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
-	}
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -185,19 +211,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/googlechat/googlechat_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
+				Config: Config{WebhookURL: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -213,64 +213,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/gotify/gotify.go

@@ -3,6 +3,7 @@ package gotify
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,40 +11,72 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const DefaultPriority = 5
 
+var (
+	ErrServerURLNotSet = errors.New("server URL not set")
+	ErrTokenNotSet     = errors.New("token not set")
+)
+
+type Config struct {
+	ServerURL string `yaml:"server-url"`         // URL of the Gotify server
+	Token     string `yaml:"token"`              // Token to use when sending a message to the Gotify server
+	Priority  int    `yaml:"priority,omitempty"` // Priority of the message. Defaults to DefaultPriority.
+	Title     string `yaml:"title,omitempty"`    // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if cfg.Priority == 0 {
+		cfg.Priority = DefaultPriority
+	}
+	if len(cfg.ServerURL) == 0 {
+		return ErrServerURLNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ServerURL) > 0 {
+		cfg.ServerURL = override.ServerURL
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if override.Priority != 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Gotify
 type AlertProvider struct {
-	// ServerURL is the URL of the Gotify server
+	DefaultConfig Config `yaml:",inline"`
-	ServerURL string `yaml:"server-url"`
-
-	// Token is the token to use when sending a message to the Gotify server
-	Token string `yaml:"token"`
-
-	// Priority is the priority of the message
-	Priority int `yaml:"priority,omitempty"` // Defaults to DefaultPriority
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if provider.Priority == 0 {
+	return provider.DefaultConfig.Validate()
-		provider.Priority = DefaultPriority
-	}
-	return len(provider.ServerURL) > 0 && len(provider.Token) > 0
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, provider.ServerURL+"/message?token="+provider.Token, buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.ServerURL+"/message?token="+cfg.Token, buffer)
 	if err != nil {
 		return err
 	}
@@ -67,7 +100,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("An alert for `%s` has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -89,13 +122,13 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	}
 	message += formattedConditionResults
 	title := "Gatus: " + ep.DisplayName()
-	if provider.Title != "" {
+	if cfg.Title != "" {
-		title = provider.Title
+		title = cfg.Title
 	}
 	bodyAsJSON, _ := json.Marshal(Body{
 		Message:  message,
 		Title:    title,
-		Priority: provider.Priority,
+		Priority: cfg.Priority,
 	})
 	return bodyAsJSON
 }
@@ -104,3 +137,25 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/gotify/gotify_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		name     string
 		provider AlertProvider
@@ -17,29 +17,29 @@ func TestAlertProvider_IsValid(t *testing.T) {
 	}{
 		{
 			name:     "valid",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			expected: true,
 		},
 		{
 			name:     "invalid-server-url",
-			provider: AlertProvider{ServerURL: "", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "", Token: "faketoken"}},
 			expected: false,
 		},
 		{
 			name:     "invalid-app-token",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: ""},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: ""}},
 			expected: false,
 		},
 		{
 			name:     "no-priority-should-use-default-value",
-			provider: AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			expected: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, func(t *testing.T) {
-			if scenario.provider.IsValid() != scenario.expected {
+			if err := scenario.provider.Validate(); (err == nil) != scenario.expected {
-				t.Errorf("expected %t, got %t", scenario.expected, scenario.provider.IsValid())
+				t.Errorf("expected: %t, got: %t", scenario.expected, err == nil)
 			}
 		})
 	}
@@ -60,21 +60,21 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been triggered due to having failed 3 time(s) in a row with the following description: %s\\n✕ - [CONNECTED] == true\\n✕ - [STATUS] == 200\",\"title\":\"Gatus: custom-endpoint\",\"priority\":0}", endpointName, description),
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been resolved after passing successfully 5 time(s) in a row with the following description: %s\\n✓ - [CONNECTED] == true\\n✓ - [STATUS] == 200\",\"title\":\"Gatus: custom-endpoint\",\"priority\":0}", endpointName, description),
 		},
 		{
 			Name:         "custom-title",
-			Provider:     AlertProvider{ServerURL: "https://gotify.example.com", Token: "faketoken", Title: "custom-title"},
+			Provider:     AlertProvider{DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "faketoken", Title: "custom-title"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: fmt.Sprintf("{\"message\":\"An alert for `%s` has been triggered due to having failed 3 time(s) in a row with the following description: %s\\n✕ - [CONNECTED] == true\\n✕ - [STATUS] == 200\",\"title\":\"custom-title\",\"priority\":0}", endpointName, description),
@@ -83,6 +83,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: endpointName},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -103,3 +104,60 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	provider := AlertProvider{DefaultAlert: &alert.Alert{}}
+	if provider.GetDefaultAlert() != provider.DefaultAlert {
+		t.Error("expected default alert to be returned")
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ServerURL: "https://gotify.example.com", Token: "12345", Priority: DefaultPriority},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ServerURL: "https://gotify.example.com", Token: "12345"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"server-url": "https://gotify.group-example.com", "token": "54321", "title": "alert-title", "priority": 3}},
+			ExpectedOutput: Config{ServerURL: "https://gotify.group-example.com", Token: "54321", Title: "alert-title", Priority: 3},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.ServerURL != scenario.ExpectedOutput.ServerURL {
+				t.Errorf("expected server URL to be %s, got %s", scenario.ExpectedOutput.ServerURL, got.ServerURL)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token to be %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			if got.Title != scenario.ExpectedOutput.Title {
+				t.Errorf("expected title to be %s, got %s", scenario.ExpectedOutput.Title, got.Title)
+			}
+			if got.Priority != scenario.ExpectedOutput.Priority {
+				t.Errorf("expected priority to be %d, got %d", scenario.ExpectedOutput.Priority, got.Priority)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/jetbrainsspace/jetbrainsspace.go

@@ -3,6 +3,7 @@ package jetbrainsspace
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,13 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrProjectNotSet          = errors.New("project not set")
+	ErrChannelIDNotSet        = errors.New("channel-id not set")
+	ErrTokenNotSet            = errors.New("token not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	Project   string `yaml:"project"`    // Project name
+	ChannelID string `yaml:"channel-id"` // Chat Channel ID
+	Token     string `yaml:"token"`      // Bearer Token
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.Project) == 0 {
+		return ErrProjectNotSet
+	}
+	if len(cfg.ChannelID) == 0 {
+		return ErrChannelIDNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.Project) > 0 {
+		cfg.Project = override.Project
+	}
+	if len(override.ChannelID) > 0 {
+		cfg.ChannelID = override.ChannelID
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using JetBrains Space
 type AlertProvider struct {
-	Project   string `yaml:"project"`    // JetBrains Space Project name
+	DefaultConfig Config `yaml:",inline"`
-	ChannelID string `yaml:"channel-id"` // JetBrains Space Chat Channel ID
-	Token     string `yaml:"token"`      // JetBrains Space Bearer Token
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -28,33 +66,37 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	ChannelID string `yaml:"channel-id"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.ChannelID) == 0 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.Project) > 0 && len(provider.ChannelID) > 0 && len(provider.Token) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	url := fmt.Sprintf("https://%s.jetbrains.space/api/http/chats/messages/send-message", provider.Project)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	url := fmt.Sprintf("https://%s.jetbrains.space/api/http/chats/messages/send-message", cfg.Project)
 	request, err := http.NewRequest(http.MethodPost, url, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", "Bearer "+provider.Token)
+	request.Header.Set("Authorization", "Bearer "+cfg.Token)
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -103,9 +145,9 @@ type Icon struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	body := Body{
-		Channel: "id:" + provider.getChannelIDForGroup(ep.Group),
+		Channel: "id:" + cfg.ChannelID,
 		Content: Content{
 			ClassName: "ChatMessage.Block",
 			Sections: []Section{{
@@ -144,19 +186,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getChannelIDForGroup returns the appropriate channel ID to for a given group override
-func (provider *AlertProvider) getChannelIDForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.ChannelID
-			}
-		}
-	}
-	return provider.ChannelID
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/jetbrainsspace/jetbrainsspace_test.go

@@ -11,54 +11,56 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{Project: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{Project: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{Project: "foo", ChannelID: "bar", Token: "baz"}
+	validProvider := AlertProvider{DefaultConfig: Config{Project: "foo", ChannelID: "bar", Token: "baz"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
-		Project: "foobar",
+		DefaultConfig: Config{Project: "foobar"},
 		Overrides: []Override{
 			{
-				ChannelID: "http://example.com",
+				Config: Config{ChannelID: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
-		Project: "foobar",
+		DefaultConfig: Config{Project: "foobar"},
 		Overrides: []Override{
 			{
-				ChannelID: "",
+				Config: Config{ChannelID: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{
 			Project:   "foo",
 			ChannelID: "bar",
 			Token:     "baz",
+		},
 		Overrides: []Override{
 			{
-				ChannelID: "foobar",
+				Config: Config{ChannelID: "foobar"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -77,7 +79,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -87,7 +89,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -97,7 +99,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -107,7 +109,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project", Token: "token"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -153,40 +155,41 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "triggered-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"WARNING","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"warning"},"style":"WARNING"},"style":"WARNING","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been triggered due to having failed 3 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
 		},
 		{
 			Name:         "resolved-with-group",
-			Provider:     AlertProvider{},
+			Provider:     AlertProvider{DefaultConfig: Config{ChannelID: "1", Project: "project"}},
 			Endpoint:     endpoint.Endpoint{Name: "name", Group: "group"},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			ExpectedBody: `{"channel":"id:","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
+			ExpectedBody: `{"channel":"id:1","content":{"className":"ChatMessage.Block","style":"SUCCESS","sections":[{"className":"MessageSection","elements":[{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[CONNECTED] == true"},{"className":"MessageText","accessory":{"className":"MessageIcon","icon":{"icon":"success"},"style":"SUCCESS"},"style":"SUCCESS","size":"REGULAR","content":"[STATUS] == 200"}],"header":"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row"}]}}`,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&scenario.Endpoint,
 				&scenario.Alert,
 				&endpoint.Result{
@@ -217,62 +220,98 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getChannelIDForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						ChannelID: "foobar",
+						Config: Config{ChannelID: "group-channel"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "bar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "default", Project: "project", Token: "token"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				ChannelID: "bar",
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						ChannelID: "foobar",
+						Config: Config{ChannelID: "group-channel"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "foobar",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ChannelID: "group-channel", Project: "project", Token: "token"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ChannelID: "default", Project: "project", Token: "token"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{ChannelID: "group-channel"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"channel-id": "alert-channel", "project": "alert-project", "token": "alert-token"}},
+			ExpectedOutput: Config{ChannelID: "alert-channel", Project: "alert-project", Token: "alert-token"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getChannelIDForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getChannelIDForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.ChannelID != scenario.ExpectedOutput.ChannelID {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.ChannelID, got.ChannelID)
+			}
+			if got.Project != scenario.ExpectedOutput.Project {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.Project, got.Project)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/matrix/matrix.go

@@ -3,6 +3,7 @@ package matrix
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
@@ -13,11 +14,56 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+const defaultServerURL = "https://matrix-client.matrix.org"
+
+var (
+	ErrAccessTokenNotSet      = errors.New("access-token not set")
+	ErrInternalRoomID         = errors.New("internal-room-id not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	// ServerURL is the custom homeserver to use (optional)
+	ServerURL string `yaml:"server-url"`
+
+	// AccessToken is the bot user's access token to send messages
+	AccessToken string `yaml:"access-token"`
+
+	// InternalRoomID is the room that the bot user has permissions to send messages to
+	InternalRoomID string `yaml:"internal-room-id"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.ServerURL) == 0 {
+		cfg.ServerURL = defaultServerURL
+	}
+	if len(cfg.AccessToken) == 0 {
+		return ErrAccessTokenNotSet
+	}
+	if len(cfg.InternalRoomID) == 0 {
+		return ErrInternalRoomID
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ServerURL) > 0 {
+		cfg.ServerURL = override.ServerURL
+	}
+	if len(override.AccessToken) > 0 {
+		cfg.AccessToken = override.AccessToken
+	}
+	if len(override.InternalRoomID) > 0 {
+		cfg.InternalRoomID = override.InternalRoomID
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Matrix
 type AlertProvider struct {
-	ProviderConfig `yaml:",inline"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -29,53 +75,39 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-
+	Config `yaml:",inline"`
-	ProviderConfig `yaml:",inline"`
 }
 
-const defaultServerURL = "https://matrix-client.matrix.org"
+// Validate the provider's configuration
-
+func (provider *AlertProvider) Validate() error {
-type ProviderConfig struct {
-	// ServerURL is the custom homeserver to use (optional)
-	ServerURL string `yaml:"server-url"`
-
-	// AccessToken is the bot user's access token to send messages
-	AccessToken string `yaml:"access-token"`
-
-	// InternalRoomID is the room that the bot user has permissions to send messages to
-	InternalRoomID string `yaml:"internal-room-id"`
-}
-
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.AccessToken) == 0 || len(override.InternalRoomID) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.AccessToken) > 0 && len(provider.InternalRoomID) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	config := provider.getConfigForGroup(ep.Group)
+	if err != nil {
-	if config.ServerURL == "" {
+		return err
-		config.ServerURL = defaultServerURL
 	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
 	// The Matrix endpoint requires a unique transaction ID for each event sent
 	txnId := randStringBytes(24)
 	request, err := http.NewRequest(
 		http.MethodPut,
 		fmt.Sprintf("%s/_matrix/client/v3/rooms/%s/send/m.room.message/%s?access_token=%s",
-			config.ServerURL,
+			cfg.ServerURL,
-			url.PathEscape(config.InternalRoomID),
+			url.PathEscape(cfg.InternalRoomID),
 			txnId,
-			url.QueryEscape(config.AccessToken),
+			url.QueryEscape(cfg.AccessToken),
 		),
 		buffer,
 	)
@@ -167,18 +199,6 @@ func buildHTMLMessageBody(ep *endpoint.Endpoint, alert *alert.Alert, result *end
 	return fmt.Sprintf("<h3>%s</h3>%s%s", message, description, formattedConditionResults)
 }
 
-// getConfigForGroup returns the appropriate configuration for a given group
-func (provider *AlertProvider) getConfigForGroup(group string) ProviderConfig {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.ProviderConfig
-			}
-		}
-	}
-	return provider.ProviderConfig
-}
-
 func randStringBytes(n int) string {
 	// All the compatible characters to use in a transaction ID
 	const availableCharacterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
@@ -194,3 +214,34 @@ func randStringBytes(n int) string {
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/matrix/matrix_test.go

@@ -11,75 +11,75 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	invalidProvider := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "",
 			InternalRoomID: "",
 		},
 	}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
 	validProvider := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 	}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 	validProviderWithHomeserver := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			ServerURL:      "https://example.com",
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 	}
-	if !validProviderWithHomeserver.IsValid() {
+	if err := validProviderWithHomeserver.Validate(); err != nil {
 		t.Error("provider with homeserver should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
 				Group: "",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					AccessToken:    "",
 					InternalRoomID: "",
 				},
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
 				Group: "group",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					AccessToken:    "",
 					InternalRoomID: "",
 				},
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		ProviderConfig: ProviderConfig{
+		DefaultConfig: Config{
 			AccessToken:    "1",
 			InternalRoomID: "!a:example.com",
 		},
 		Overrides: []Override{
 			{
 				Group: "group",
-				ProviderConfig: ProviderConfig{
+				Config: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -87,7 +87,7 @@ func TestAlertProvider_IsValidWithOverride(t *testing.T) {
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -105,18 +105,28 @@ func TestAlertProvider_Send(t *testing.T) {
 		ExpectedError    bool
 	}{
 		{
-			Name:     "triggered",
+			Name:     "triggered-with-bad-config",
 			Provider: AlertProvider{},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
 				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
 			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
 			ExpectedError: false,
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -126,7 +136,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -136,7 +146,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessToken: "1", InternalRoomID: "!a:example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -227,17 +237,18 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getConfigForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput ProviderConfig
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -245,7 +256,8 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: nil,
 			},
 			InputGroup: "",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -254,7 +266,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -262,7 +274,8 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: nil,
 			},
 			InputGroup: "group",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -271,7 +284,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -279,16 +292,17 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: []Override{
 					{
 						Group: "group",
-						ProviderConfig: ProviderConfig{
+						Config: Config{
-							ServerURL:      "https://example01.com",
+							ServerURL:      "https://group-example.com",
 							AccessToken:    "12",
-							InternalRoomID: "!a:example01.com",
+							InternalRoomID: "!a:group-example.com",
 						},
 					},
 				},
 			},
 			InputGroup: "",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
 				ServerURL:      "https://example.com",
 				AccessToken:    "1",
 				InternalRoomID: "!a:example.com",
@@ -297,7 +311,7 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				ProviderConfig: ProviderConfig{
+				DefaultConfig: Config{
 					ServerURL:      "https://example.com",
 					AccessToken:    "1",
 					InternalRoomID: "!a:example.com",
@@ -305,8 +319,35 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				Overrides: []Override{
 					{
 						Group: "group",
-						ProviderConfig: ProviderConfig{
+						Config: Config{
-							ServerURL:      "https://example01.com",
+							ServerURL:      "https://group-example.com",
+							AccessToken:    "12",
+							InternalRoomID: "!a:group-example.com",
+						},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
+				ServerURL:      "https://group-example.com",
+				AccessToken:    "12",
+				InternalRoomID: "!a:group-example.com",
+			},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						Config: Config{
+							ServerURL:      "https://group-example.com",
 							AccessToken:    "12",
 							InternalRoomID: "!a:example01.com",
 						},
@@ -314,17 +355,32 @@ func TestAlertProvider_getConfigForGroup(t *testing.T) {
 				},
 			},
 			InputGroup: "group",
-			ExpectedOutput: ProviderConfig{
+			InputAlert: alert.Alert{ProviderOverride: map[string]any{"server-url": "https://alert-example.com", "access-token": "123", "internal-room-id": "!a:alert-example.com"}},
-				ServerURL:      "https://example01.com",
+			ExpectedOutput: Config{
-				AccessToken:    "12",
+				ServerURL:      "https://alert-example.com",
-				InternalRoomID: "!a:example01.com",
+				AccessToken:    "123",
+				InternalRoomID: "!a:alert-example.com",
 			},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getConfigForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			outputConfig, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getConfigForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Errorf("expected no error, got %v", err)
+			}
+			if outputConfig.ServerURL != scenario.ExpectedOutput.ServerURL {
+				t.Errorf("expected ServerURL to be %s, got %s", scenario.ExpectedOutput.ServerURL, outputConfig.ServerURL)
+			}
+			if outputConfig.AccessToken != scenario.ExpectedOutput.AccessToken {
+				t.Errorf("expected AccessToken to be %s, got %s", scenario.ExpectedOutput.AccessToken, outputConfig.AccessToken)
+			}
+			if outputConfig.InternalRoomID != scenario.ExpectedOutput.InternalRoomID {
+				t.Errorf("expected InternalRoomID to be %s, got %s", scenario.ExpectedOutput.InternalRoomID, outputConfig.InternalRoomID)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/mattermost/mattermost.go

@@ -3,6 +3,7 @@ package mattermost
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,17 +11,42 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook URL not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL   string         `yaml:"webhook-url"`
+	Channel      string         `yaml:"channel,omitempty"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Channel) > 0 {
+		cfg.Channel = override.Channel
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Mattermost
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
-
-	// Channel is the optional setting to override the default webhook's channel
-	Channel string `yaml:"channel,omitempty"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -32,35 +58,36 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if provider.ClientConfig == nil {
-		provider.ClientConfig = client.GetDefaultConfig()
-	}
 	if provider.Overrides != nil {
 		registeredGroups := make(map[string]bool)
 		for _, override := range provider.Overrides {
 			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(ep, alert, result, resolved)))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(cfg, ep, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -96,7 +123,7 @@ type Field struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, color string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -122,7 +149,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		description = ":\n> " + alertDescription
 	}
 	body := Body{
-		Channel:  provider.Channel,
+		Channel:  cfg.Channel,
 		Text:     "",
 		Username: "gatus",
 		IconURL:  "https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png",
@@ -147,19 +174,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/mattermost/mattermost_test.go

@@ -11,54 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
-	if providerWithInvalidOverrideGroup.IsValid() {
 		t.Error("provider Group shouldn't have been valid")
 	}
-
 	providerWithInvalidOverrideWebHookUrl := AlertProvider{
 		Overrides: []Override{
 			{
-
+				Config: Config{WebhookURL: ""},
-				WebhookURL: "",
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideWebHookUrl.IsValid() {
+	if err := providerWithInvalidOverrideWebHookUrl.Validate(); err == nil {
 		t.Error("provider WebHookURL shouldn't have been valid")
 	}
-
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -77,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -87,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -97,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -107,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -168,6 +164,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -198,64 +195,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/messagebird/messagebird.go

@@ -3,6 +3,7 @@ package messagebird
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,37 +11,75 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-const (
+const restAPIURL = "https://rest.messagebird.com/messages"
-	restAPIURL = "https://rest.messagebird.com/messages"
+
+var (
+	ErrorAccessKeyNotSet  = errors.New("access-key not set")
+	ErrorOriginatorNotSet = errors.New("originator not set")
+	ErrorRecipientsNotSet = errors.New("recipients not set")
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Messagebird
+type Config struct {
-type AlertProvider struct {
 	AccessKey  string `yaml:"access-key"`
 	Originator string `yaml:"originator"`
 	Recipients string `yaml:"recipients"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.AccessKey) == 0 {
+		return ErrorAccessKeyNotSet
+	}
+	if len(cfg.Originator) == 0 {
+		return ErrorOriginatorNotSet
+	}
+	if len(cfg.Recipients) == 0 {
+		return ErrorRecipientsNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.AccessKey) > 0 {
+		cfg.AccessKey = override.AccessKey
+	}
+	if len(override.Originator) > 0 {
+		cfg.Originator = override.Originator
+	}
+	if len(override.Recipients) > 0 {
+		cfg.Recipients = override.Recipients
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Messagebird
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	return len(provider.AccessKey) > 0 && len(provider.Originator) > 0 && len(provider.Recipients) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 // Reference doc for messagebird: https://developers.messagebird.com/api/sms-messaging/#send-outbound-sms
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
 	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", fmt.Sprintf("AccessKey %s", provider.AccessKey))
+	request.Header.Set("Authorization", fmt.Sprintf("AccessKey %s", cfg.AccessKey))
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -60,7 +99,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
@@ -68,8 +107,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		message = fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
 	}
 	body, _ := json.Marshal(Body{
-		Originator: provider.Originator,
+		Originator: cfg.Originator,
-		Recipients: provider.Recipients,
+		Recipients: cfg.Recipients,
 		Body:       message,
 	})
 	return body
@@ -79,3 +118,25 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/messagebird/messagebird_test.go

@@ -13,15 +13,17 @@ import (
 
 func TestMessagebirdAlertProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
 	validProvider := AlertProvider{
+		DefaultConfig: Config{
 			AccessKey:  "1",
 			Originator: "1",
 			Recipients: "1",
+		},
 	}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -40,7 +42,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -50,7 +52,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -60,7 +62,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -70,7 +72,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -115,14 +117,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{AccessKey: "1", Originator: "2", Recipients: "3"},
+			Provider:     AlertProvider{DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"originator\":\"2\",\"recipients\":\"3\",\"body\":\"TRIGGERED: endpoint-name - description-1\"}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{AccessKey: "4", Originator: "5", Recipients: "6"},
+			Provider:     AlertProvider{DefaultConfig: Config{AccessKey: "4", Originator: "5", Recipients: "6"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"originator\":\"5\",\"recipients\":\"6\",\"body\":\"RESOLVED: endpoint-name - description-2\"}",
@@ -131,6 +133,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -145,7 +148,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
 			}
 			out := make(map[string]interface{})
-			if err := json.Unmarshal([]byte(body), &out); err != nil {
+			if err := json.Unmarshal(body, &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
 		})
@@ -160,3 +163,50 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{AccessKey: "1", Originator: "2", Recipients: "3"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"access-key": "4", "originator": "5", "recipients": "6"}},
+			ExpectedOutput: Config{AccessKey: "4", Originator: "5", Recipients: "6"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.AccessKey != scenario.ExpectedOutput.AccessKey {
+				t.Errorf("expected access key to be %s, got %s", scenario.ExpectedOutput.AccessKey, got.AccessKey)
+			}
+			if got.Originator != scenario.ExpectedOutput.Originator {
+				t.Errorf("expected originator to be %s, got %s", scenario.ExpectedOutput.Originator, got.Originator)
+			}
+			if got.Recipients != scenario.ExpectedOutput.Recipients {
+				t.Errorf("expected recipients to be %s, got %s", scenario.ExpectedOutput.Recipients, got.Recipients)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/ntfy/ntfy.go

@@ -3,6 +3,7 @@ package ntfy
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,6 +13,7 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -20,8 +22,14 @@ const (
 	TokenPrefix     = "tk_"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Slack
+var (
-type AlertProvider struct {
+	ErrInvalidToken           = errors.New("invalid token")
+	ErrTopicNotSet            = errors.New("topic not set")
+	ErrInvalidPriority        = errors.New("priority must between 1 and 5 inclusively")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
 	Topic           string `yaml:"topic"`
 	URL             string `yaml:"url,omitempty"`              // Defaults to DefaultURL
 	Priority        int    `yaml:"priority,omitempty"`         // Defaults to DefaultPriority
@@ -30,6 +38,57 @@ type AlertProvider struct {
 	Click           string `yaml:"click,omitempty"`            // Defaults to ""
 	DisableFirebase bool   `yaml:"disable-firebase,omitempty"` // Defaults to false
 	DisableCache    bool   `yaml:"disable-cache,omitempty"`    // Defaults to false
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		cfg.URL = DefaultURL
+	}
+	if cfg.Priority == 0 {
+		cfg.Priority = DefaultPriority
+	}
+	if len(cfg.Token) > 0 && !strings.HasPrefix(cfg.Token, TokenPrefix) {
+		return ErrInvalidToken
+	}
+	if len(cfg.Topic) == 0 {
+		return ErrTopicNotSet
+	}
+	if cfg.Priority < 1 || cfg.Priority > 5 {
+		return ErrInvalidPriority
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.Topic) > 0 {
+		cfg.Topic = override.Topic
+	}
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if override.Priority > 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.Email) > 0 {
+		cfg.Email = override.Email
+	}
+	if len(override.Click) > 0 {
+		cfg.Click = override.Click
+	}
+	if override.DisableFirebase {
+		cfg.DisableFirebase = true
+	}
+	if override.DisableCache {
+		cfg.DisableCache = true
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Slack
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -41,65 +100,53 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	Topic    string `yaml:"topic"`
+	Config `yaml:",inline"`
-	URL      string `yaml:"url"`
-	Priority int    `yaml:"priority"`
-	Token    string `yaml:"token"`
-	Email    string `yaml:"email"`
-	Click    string `yaml:"click"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if len(provider.URL) == 0 {
-		provider.URL = DefaultURL
-	}
-	if provider.Priority == 0 {
-		provider.Priority = DefaultPriority
-	}
-	isTokenValid := true
-	if len(provider.Token) > 0 {
-		isTokenValid = strings.HasPrefix(provider.Token, TokenPrefix)
-	}
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if len(override.Group) == 0 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			if _, ok := registeredGroups[override.Group]; ok {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			if len(override.Token) > 0 && !strings.HasPrefix(override.Token, TokenPrefix) {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			if override.Priority < 0 || override.Priority >= 6 {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
 
-	return len(provider.URL) > 0 && len(provider.Topic) > 0 && provider.Priority > 0 && provider.Priority < 6 && isTokenValid
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	override := provider.getGroupOverride(ep.Group)
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved, override))
+	if err != nil {
-	url := provider.getURL(override)
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	url := cfg.URL
 	request, err := http.NewRequest(http.MethodPost, url, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	if token := provider.getToken(override); len(token) > 0 {
+	if token := cfg.Token; len(token) > 0 {
 		request.Header.Set("Authorization", "Bearer "+token)
 	}
-	if provider.DisableFirebase {
+	if cfg.DisableFirebase {
 		request.Header.Set("Firebase", "no")
 	}
-	if provider.DisableCache {
+	if cfg.DisableCache {
 		request.Header.Set("Cache", "no")
 	}
 	response, err := client.GetHTTPClient(nil).Do(request)
@@ -125,7 +172,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool, override *Override) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, formattedConditionResults, tag string
 	if resolved {
 		tag = "white_check_mark"
@@ -148,13 +195,13 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	}
 	message += formattedConditionResults
 	body, _ := json.Marshal(Body{
-		Topic:    provider.getTopic(override),
+		Topic:    cfg.Topic,
 		Title:    "Gatus: " + ep.DisplayName(),
 		Message:  message,
 		Tags:     []string{tag},
-		Priority: provider.getPriority(override),
+		Priority: cfg.Priority,
-		Email:    provider.getEmail(override),
+		Email:    cfg.Email,
-		Click:    provider.getClick(override),
+		Click:    cfg.Click,
 	})
 	return body
 }
@@ -164,55 +211,33 @@ func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
-func (provider *AlertProvider) getGroupOverride(group string) *Override {
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
 			if group == override.Group {
-				return &override
+				cfg.Merge(&override.Config)
+				break
 			}
 		}
 	}
-	return nil
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
 }
 
-func (provider *AlertProvider) getTopic(override *Override) string {
+// ValidateOverrides validates the alert's provider override and, if present, the group override
-	if override != nil && len(override.Topic) > 0 {
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
-		return override.Topic
+	_, err := provider.GetConfig(group, alert)
-	}
+	return err
-	return provider.Topic
-}
-
-func (provider *AlertProvider) getURL(override *Override) string {
-	if override != nil && len(override.URL) > 0 {
-		return override.URL
-	}
-	return provider.URL
-}
-
-func (provider *AlertProvider) getPriority(override *Override) int {
-	if override != nil && override.Priority > 0 {
-		return override.Priority
-	}
-	return provider.Priority
-}
-
-func (provider *AlertProvider) getToken(override *Override) string {
-	if override != nil && len(override.Token) > 0 {
-		return override.Token
-	}
-	return provider.Token
-}
-
-func (provider *AlertProvider) getEmail(override *Override) string {
-	if override != nil && len(override.Email) > 0 {
-		return override.Email
-	}
-	return provider.Email
-}
-
-func (provider *AlertProvider) getClick(override *Override) string {
-	if override != nil && len(override.Click) > 0 {
-		return override.Click
-	}
-	return provider.Click
 }

alerting/provider/ntfy/ntfy_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/endpoint"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	scenarios := []struct {
 		name     string
 		provider AlertProvider
@@ -19,74 +19,78 @@ func TestAlertDefaultProvider_IsValid(t *testing.T) {
 	}{
 		{
 			name:     "valid",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1}},
 			expected: true,
 		},
 		{
 			name:     "no-url-should-use-default-value",
-			provider: AlertProvider{Topic: "example", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1}},
 			expected: true,
 		},
 		{
 			name:     "valid-with-token",
-			provider: AlertProvider{Topic: "example", Priority: 1, Token: "tk_faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1, Token: "tk_faketoken"}},
 			expected: true,
 		},
 		{
 			name:     "invalid-token",
-			provider: AlertProvider{Topic: "example", Priority: 1, Token: "xx_faketoken"},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example", Priority: 1, Token: "xx_faketoken"}},
 			expected: false,
 		},
 		{
 			name:     "invalid-topic",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "", Priority: 1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "", Priority: 1}},
 			expected: false,
 		},
 		{
 			name:     "invalid-priority-too-high",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 6},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 6}},
 			expected: false,
 		},
 		{
 			name:     "invalid-priority-too-low",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: -1},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: -1}},
 			expected: false,
 		},
 		{
 			name:     "no-priority-should-use-default-value",
-			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example"},
+			provider: AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example"}},
 			expected: true,
 		},
 		{
 			name:     "invalid-override-token",
-			provider: AlertProvider{Topic: "example", Overrides: []Override{Override{Group: "g", Token: "xx_faketoken"}}},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g", Config: Config{Token: "xx_faketoken"}}}},
 			expected: false,
 		},
 		{
 			name:     "invalid-override-priority",
-			provider: AlertProvider{Topic: "example", Overrides: []Override{Override{Group: "g", Priority: 8}}},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g", Config: Config{Priority: 8}}}},
 			expected: false,
 		},
 		{
 			name:     "no-override-group-name",
-			provider: AlertProvider{Topic: "example", Overrides: []Override{Override{}}},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{}}},
 			expected: false,
 		},
 		{
 			name:     "duplicate-override-group-names",
-			provider: AlertProvider{Topic: "example", Overrides: []Override{Override{Group: "g"}, Override{Group: "g"}}},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g"}, {Group: "g"}}},
 			expected: false,
 		},
 		{
 			name:     "valid-override",
-			provider: AlertProvider{Topic: "example", Overrides: []Override{Override{Group: "g1", Priority: 4, Click: "https://example.com"}, Override{Group: "g2", Topic: "Example", Token: "tk_faketoken"}}},
+			provider: AlertProvider{DefaultConfig: Config{Topic: "example"}, Overrides: []Override{{Group: "g1", Config: Config{Priority: 4, Click: "https://example.com"}}, {Group: "g2", Config: Config{Topic: "Example", Token: "tk_faketoken"}}}},
 			expected: true,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.name, func(t *testing.T) {
-			if scenario.provider.IsValid() != scenario.expected {
+			err := scenario.provider.Validate()
-				t.Errorf("expected %t, got %t", scenario.expected, scenario.provider.IsValid())
+			if scenario.expected && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+			if !scenario.expected && err == nil {
+				t.Error("expected error, got none")
 			}
 		})
 	}
@@ -100,53 +104,59 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		Provider     AlertProvider
 		Alert        alert.Alert
 		Resolved     bool
-		Override     *Override
 		ExpectedBody string
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			Override:     nil,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1}`,
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 2},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 2}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			Override:     nil,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\n🟢 [CONNECTED] == true\n🟢 [STATUS] == 200","tags":["white_check_mark"],"priority":2}`,
 		},
 		{
 			Name:         "triggered-email",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			Override:     nil,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":1,"email":"test@example.com","click":"example.com"}`,
 		},
 		{
 			Name:         "resolved-email",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 2, Email: "test@example.com", Click: "example.com"},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 2, Email: "test@example.com", Click: "example.com"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
-			Override:     nil,
 			ExpectedBody: `{"topic":"example","title":"Gatus: endpoint-name","message":"An alert has been resolved after passing successfully 5 time(s) in a row with the following description: description-2\n🟢 [CONNECTED] == true\n🟢 [STATUS] == 200","tags":["white_check_mark"],"priority":2,"email":"test@example.com","click":"example.com"}`,
 		},
 		{
-			Name:         "override",
+			Name:         "group-override",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 5, Email: "test@example.com", Click: "example.com"},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 5, Email: "test@example.com", Click: "example.com"}, Overrides: []Override{{Group: "g", Config: Config{Topic: "group-topic", Priority: 4, Email: "override@test.com", Click: "test.com"}}}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
-			Override:     &Override{Group: "g", Topic: "override-topic", Priority: 4, Email: "override@test.com", Click: "test.com"},
+			ExpectedBody: `{"topic":"group-topic","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":4,"email":"override@test.com","click":"test.com"}`,
-			ExpectedBody: `{"topic":"override-topic","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":4,"email":"override@test.com","click":"test.com"}`,
+		},
+		{
+			Name:         "alert-override",
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 5, Email: "test@example.com", Click: "example.com"}, Overrides: []Override{{Group: "g", Config: Config{Topic: "group-topic", Priority: 4, Email: "override@test.com", Click: "test.com"}}}},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3, ProviderOverride: map[string]any{"topic": "alert-topic"}},
+			Resolved:     false,
+			ExpectedBody: `{"topic":"alert-topic","title":"Gatus: endpoint-name","message":"An alert has been triggered due to having failed 3 time(s) in a row with the following description: description-1\n🔴 [CONNECTED] == true\n🔴 [STATUS] == 200","tags":["rotating_light"],"priority":4,"email":"override@test.com","click":"test.com"}`,
 		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
+			cfg, err := scenario.Provider.GetConfig("g", &scenario.Alert)
+			if err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
 			body := scenario.Provider.buildRequestBody(
+				cfg,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -156,7 +166,6 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 					},
 				},
 				scenario.Resolved,
-				scenario.Override,
 			)
 			if string(body) != scenario.ExpectedBody {
 				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
@@ -182,7 +191,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "",
@@ -193,7 +202,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:         "token",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken"},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken"}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "",
@@ -205,7 +214,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:         "no firebase",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "",
@@ -217,7 +226,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:         "no cache",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableCache: true},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableCache: true}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "",
@@ -229,7 +238,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:         "neither firebase & cache",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true, DisableCache: true},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", DisableFirebase: true, DisableCache: true}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "",
@@ -242,7 +251,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:         "overrides",
-			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken", Overrides: []Override{Override{Group: "other-group", URL: "https://example.com", Token: "tk_othertoken"}, Override{Group: "test-group", Token: "tk_test_token"}}},
+			Provider:     AlertProvider{DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1, Email: "test@example.com", Click: "example.com", Token: "tk_mytoken"}, Overrides: []Override{Override{Group: "other-group", Config: Config{URL: "https://example.com", Token: "tk_othertoken"}}, Override{Group: "test-group", Config: Config{Token: "tk_test_token"}}}},
 			Alert:        alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			Group:        "test-group",
@@ -273,7 +282,7 @@ func TestAlertProvider_Send(t *testing.T) {
 			// Close the server when test finishes
 			defer server.Close()
 
-			scenario.Provider.URL = server.URL
+			scenario.Provider.DefaultConfig.URL = server.URL
 			err := scenario.Provider.Send(
 				&endpoint.Endpoint{Name: "endpoint-name", Group: scenario.Group},
 				&scenario.Alert,
@@ -288,8 +297,118 @@ func TestAlertProvider_Send(t *testing.T) {
 			if err != nil {
 				t.Error("Encountered an error on Send: ", err)
 			}
-
 		})
 	}
-
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{URL: "https://group-example.com", Topic: "group-topic", Priority: 2},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"url": "http://alert-example.com", "topic": "alert-topic", "priority": 3}},
+			ExpectedOutput: Config{URL: "http://alert-example.com", Topic: "alert-topic", Priority: 3},
+		},
+		{
+			Name: "provider-with-partial-overrides",
+			Provider: AlertProvider{
+				DefaultConfig: Config{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{Topic: "group-topic"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"priority": 3}},
+			ExpectedOutput: Config{URL: "https://ntfy.sh", Topic: "group-topic", Priority: 3},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.URL != scenario.ExpectedOutput.URL {
+				t.Errorf("expected url %s, got %s", scenario.ExpectedOutput.URL, got.URL)
+			}
+			if got.Topic != scenario.ExpectedOutput.Topic {
+				t.Errorf("expected topic %s, got %s", scenario.ExpectedOutput.Topic, got.Topic)
+			}
+			if got.Priority != scenario.ExpectedOutput.Priority {
+				t.Errorf("expected priority %d, got %d", scenario.ExpectedOutput.Priority, got.Priority)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
 }

alerting/provider/opsgenie/opsgenie.go

@@ -3,6 +3,7 @@ package opsgenie
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,13 +13,18 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	restAPI = "https://api.opsgenie.com/v2/alerts"
 )
 
-type AlertProvider struct {
+var (
+	ErrAPIKeyNotSet = errors.New("api-key not set")
+)
+
+type Config struct {
 	// APIKey to use for
 	APIKey string `yaml:"api-key"`
 
@@ -46,26 +52,74 @@ type AlertProvider struct {
 	//
 	// default: []
 	Tags []string `yaml:"tags"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.APIKey) == 0 {
+		return ErrAPIKeyNotSet
+	}
+	if len(cfg.Source) == 0 {
+		cfg.Source = "gatus"
+	}
+	if len(cfg.EntityPrefix) == 0 {
+		cfg.EntityPrefix = "gatus-"
+	}
+	if len(cfg.AliasPrefix) == 0 {
+		cfg.AliasPrefix = "gatus-healthcheck-"
+	}
+	if len(cfg.Priority) == 0 {
+		cfg.Priority = "P1"
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.APIKey) > 0 {
+		cfg.APIKey = override.APIKey
+	}
+	if len(override.Priority) > 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Source) > 0 {
+		cfg.Source = override.Source
+	}
+	if len(override.EntityPrefix) > 0 {
+		cfg.EntityPrefix = override.EntityPrefix
+	}
+	if len(override.AliasPrefix) > 0 {
+		cfg.AliasPrefix = override.AliasPrefix
+	}
+	if len(override.Tags) > 0 {
+		cfg.Tags = override.Tags
+	}
+}
+
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	return len(provider.APIKey) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 //
 // Relevant: https://docs.opsgenie.com/docs/alert-api
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	err := provider.createAlert(ep, alert, result, resolved)
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	err = provider.sendAlertRequest(cfg, ep, alert, result, resolved)
 	if err != nil {
 		return err
 	}
 	if resolved {
-		err = provider.closeAlert(ep, alert)
+		err = provider.closeAlert(cfg, ep, alert)
 		if err != nil {
 			return err
 		}
@@ -75,24 +129,24 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 			// The alert has been resolved and there's no error, so we can clear the alert's ResolveKey
 			alert.ResolveKey = ""
 		} else {
-			alert.ResolveKey = provider.alias(buildKey(ep))
+			alert.ResolveKey = cfg.AliasPrefix + buildKey(ep)
 		}
 	}
 	return nil
 }
 
-func (provider *AlertProvider) createAlert(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+func (provider *AlertProvider) sendAlertRequest(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	payload := provider.buildCreateRequestBody(ep, alert, result, resolved)
+	payload := provider.buildCreateRequestBody(cfg, ep, alert, result, resolved)
-	return provider.sendRequest(restAPI, http.MethodPost, payload)
+	return provider.sendRequest(cfg, restAPI, http.MethodPost, payload)
 }
 
-func (provider *AlertProvider) closeAlert(ep *endpoint.Endpoint, alert *alert.Alert) error {
+func (provider *AlertProvider) closeAlert(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert) error {
 	payload := provider.buildCloseRequestBody(ep, alert)
-	url := restAPI + "/" + provider.alias(buildKey(ep)) + "/close?identifierType=alias"
+	url := restAPI + "/" + cfg.AliasPrefix + buildKey(ep) + "/close?identifierType=alias"
-	return provider.sendRequest(url, http.MethodPost, payload)
+	return provider.sendRequest(cfg, url, http.MethodPost, payload)
 }
 
-func (provider *AlertProvider) sendRequest(url, method string, payload interface{}) error {
+func (provider *AlertProvider) sendRequest(cfg *Config, url, method string, payload interface{}) error {
 	body, err := json.Marshal(payload)
 	if err != nil {
 		return fmt.Errorf("error build alert with payload %v: %w", payload, err)
@@ -102,7 +156,7 @@ func (provider *AlertProvider) sendRequest(url, method string, payload interface
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	request.Header.Set("Authorization", "GenieKey "+provider.APIKey)
+	request.Header.Set("Authorization", "GenieKey "+cfg.APIKey)
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -115,7 +169,7 @@ func (provider *AlertProvider) sendRequest(url, method string, payload interface
 	return nil
 }
 
-func (provider *AlertProvider) buildCreateRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) alertCreateRequest {
+func (provider *AlertProvider) buildCreateRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) alertCreateRequest {
 	var message, description string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.Name, alert.GetDescription())
@@ -158,11 +212,11 @@ func (provider *AlertProvider) buildCreateRequestBody(ep *endpoint.Endpoint, ale
 	return alertCreateRequest{
 		Message:     message,
 		Description: description,
-		Source:      provider.source(),
+		Source:      cfg.Source,
-		Priority:    provider.priority(),
+		Priority:    cfg.Priority,
-		Alias:       provider.alias(key),
+		Alias:       cfg.AliasPrefix + key,
-		Entity:      provider.entity(key),
+		Entity:      cfg.EntityPrefix + key,
-		Tags:        provider.Tags,
+		Tags:        cfg.Tags,
 		Details:     details,
 	}
 }
@@ -174,43 +228,33 @@ func (provider *AlertProvider) buildCloseRequestBody(ep *endpoint.Endpoint, aler
 	}
 }
 
-func (provider *AlertProvider) source() string {
-	source := provider.Source
-	if source == "" {
-		return "gatus"
-	}
-	return source
-}
-
-func (provider *AlertProvider) alias(key string) string {
-	alias := provider.AliasPrefix
-	if alias == "" {
-		alias = "gatus-healthcheck-"
-	}
-	return alias + key
-}
-
-func (provider *AlertProvider) entity(key string) string {
-	alias := provider.EntityPrefix
-	if alias == "" {
-		alias = "gatus-"
-	}
-	return alias + key
-}
-
-func (provider *AlertProvider) priority() string {
-	priority := provider.Priority
-	if priority == "" {
-		return "P1"
-	}
-	return priority
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}
+
 func buildKey(ep *endpoint.Endpoint) string {
 	name := toKebabCase(ep.Name)
 	if ep.Group == "" {

alerting/provider/opsgenie/opsgenie_test.go

@@ -11,13 +11,13 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{APIKey: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{APIKey: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{APIKey: "00000000-0000-0000-0000-000000000000"}
+	validProvider := AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -35,7 +35,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:          "triggered",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 1, FailureThreshold: 1},
 			Resolved:      false,
 			ExpectedError: false,
@@ -45,7 +45,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "triggered-error",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      false,
 			ExpectedError: true,
@@ -55,7 +55,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: false,
@@ -65,7 +65,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:          "resolved-error",
-			Provider:      AlertProvider{},
+			Provider:      AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:      true,
 			ExpectedError: true,
@@ -74,7 +74,6 @@ func TestAlertProvider_Send(t *testing.T) {
 			}),
 		},
 	}
-
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
@@ -113,7 +112,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 	}{
 		{
 			Name:     "missing all params (unresolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:    &alert.Alert{},
 			Endpoint: &endpoint.Endpoint{},
 			Result:   &endpoint.Result{},
@@ -131,7 +130,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		},
 		{
 			Name:     "missing all params (resolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert:    &alert.Alert{},
 			Endpoint: &endpoint.Endpoint{},
 			Result:   &endpoint.Result{},
@@ -149,7 +148,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		},
 		{
 			Name:     "with default options (unresolved)",
-			Provider: &AlertProvider{},
+			Provider: &AlertProvider{DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"}},
 			Alert: &alert.Alert{
 				Description:      &description,
 				FailureThreshold: 3,
@@ -184,12 +183,14 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		{
 			Name: "with custom options (resolved)",
 			Provider: &AlertProvider{
+				DefaultConfig: Config{
 					Priority:     "P5",
 					EntityPrefix: "oompa-",
 					AliasPrefix:  "loompa-",
 					Source:       "gatus-hc",
 					Tags:         []string{"do-ba-dee-doo"},
 				},
+			},
 			Alert: &alert.Alert{
 				Description:      &description,
 				SuccessThreshold: 4,
@@ -220,7 +221,7 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 		{
 			Name: "with default options and details (unresolved)",
 			Provider: &AlertProvider{
-				Tags: []string{"foo"},
+				DefaultConfig: Config{Tags: []string{"foo"}, APIKey: "00000000-0000-0000-0000-000000000000"},
 			},
 			Alert: &alert.Alert{
 				Description:      &description,
@@ -265,8 +266,9 @@ func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		actual := scenario
 		t.Run(actual.Name, func(t *testing.T) {
-			if got := actual.Provider.buildCreateRequestBody(actual.Endpoint, actual.Alert, actual.Result, actual.Resolved); !reflect.DeepEqual(got, actual.want) {
+			_ = scenario.Provider.Validate()
-				t.Errorf("buildCreateRequestBody() = %v, want %v", got, actual.want)
+			if got := actual.Provider.buildCreateRequestBody(&scenario.Provider.DefaultConfig, actual.Endpoint, actual.Alert, actual.Result, actual.Resolved); !reflect.DeepEqual(got, actual.want) {
+				t.Errorf("got:\n%v\nwant:\n%v", got, actual.want)
 			}
 		})
 	}
@@ -307,7 +309,6 @@ func TestAlertProvider_buildCloseRequestBody(t *testing.T) {
 			},
 		},
 	}
-
 	for _, scenario := range scenarios {
 		actual := scenario
 		t.Run(actual.Name, func(t *testing.T) {
@@ -317,3 +318,44 @@ func TestAlertProvider_buildCloseRequestBody(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+		},
+		{
+			Name: "provider-with-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{APIKey: "00000000-0000-0000-0000-000000000000"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"api-key": "00000000-0000-0000-0000-000000000001"}},
+			ExpectedOutput: Config{APIKey: "00000000-0000-0000-0000-000000000001"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.APIKey != scenario.ExpectedOutput.APIKey {
+				t.Errorf("expected APIKey to be %s, got %s", scenario.ExpectedOutput.APIKey, got.APIKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/pagerduty/pagerduty.go

@@ -3,6 +3,7 @@ package pagerduty
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -11,15 +12,38 @@ import (
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/TwiN/logr"
+	"gopkg.in/yaml.v3"
 )
 
 const (
 	restAPIURL = "https://events.pagerduty.com/v2/enqueue"
 )
 
+var (
+	ErrIntegrationKeyNotSet   = errors.New("integration-key must have exactly 32 characters")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	IntegrationKey string `yaml:"integration-key"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.IntegrationKey) != 32 {
+		return ErrIntegrationKeyNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.IntegrationKey) > 0 {
+		cfg.IntegrationKey = override.IntegrationKey
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using PagerDuty
 type AlertProvider struct {
-	IntegrationKey string `yaml:"integration-key"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
@@ -31,29 +55,33 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	IntegrationKey string `yaml:"integration-key"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.IntegrationKey) != 32 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
 	// Either the default integration key has the right length, or there are overrides who are properly configured.
-	return len(provider.IntegrationKey) == 32 || len(provider.Overrides) != 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 //
 // Relevant: https://developer.pagerduty.com/docs/events-api-v2/trigger-events/
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
 	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
 	if err != nil {
 		return err
@@ -100,7 +128,7 @@ type Payload struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, eventAction, resolveKey string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
@@ -112,7 +140,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		resolveKey = ""
 	}
 	body, _ := json.Marshal(Body{
-		RoutingKey:  provider.getIntegrationKeyForGroup(ep.Group),
+		RoutingKey:  cfg.IntegrationKey,
 		DedupKey:    resolveKey,
 		EventAction: eventAction,
 		Payload: Payload{
@@ -124,23 +152,42 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return body
 }
 
-// getIntegrationKeyForGroup returns the appropriate pagerduty integration key for a given group
-func (provider *AlertProvider) getIntegrationKeyForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.IntegrationKey
-			}
-		}
-	}
-	return provider.IntegrationKey
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
 
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}
+
 type pagerDutyResponsePayload struct {
 	Status   string `json:"status"`
 	Message  string `json:"message"`

alerting/provider/pagerduty/pagerduty_test.go

@@ -11,50 +11,41 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{IntegrationKey: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{IntegrationKey: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
+	validProvider := AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
 		Overrides: []Override{
 			{
-				IntegrationKey: "00000000000000000000000000000000",
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
-	providerWithInvalidOverrideIntegrationKey := AlertProvider{
-		Overrides: []Override{
-			{
-				IntegrationKey: "",
-				Group:          "group",
-			},
-		},
-	}
-	if providerWithInvalidOverrideIntegrationKey.IsValid() {
-		t.Error("provider integration key shouldn't have been valid")
-	}
 	providerWithValidOverride := AlertProvider{
+		DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
 		Overrides: []Override{
 			{
-				IntegrationKey: "00000000000000000000000000000000",
+				Config: Config{IntegrationKey: "00000000000000000000000000000002"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
-		t.Error("provider should've been valid")
+		t.Error("provider should've been valid, got error:", err.Error())
 	}
 }
 
@@ -72,7 +63,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -82,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -92,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -102,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -146,14 +137,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:        alert.Alert{Description: &description},
 			Resolved:     false,
 			ExpectedBody: "{\"routing_key\":\"00000000000000000000000000000000\",\"dedup_key\":\"\",\"event_action\":\"trigger\",\"payload\":{\"summary\":\"TRIGGERED: endpoint-name - test\",\"source\":\"Gatus\",\"severity\":\"critical\"}}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Provider:     AlertProvider{DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000000"}},
 			Alert:        alert.Alert{Description: &description, ResolveKey: "key"},
 			Resolved:     true,
 			ExpectedBody: "{\"routing_key\":\"00000000000000000000000000000000\",\"dedup_key\":\"key\",\"event_action\":\"resolve\",\"payload\":{\"summary\":\"RESOLVED: endpoint-name - test\",\"source\":\"Gatus\",\"severity\":\"critical\"}}",
@@ -161,7 +152,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			body := scenario.Provider.buildRequestBody(&endpoint.Endpoint{Name: "endpoint-name"}, &scenario.Alert, &endpoint.Result{}, scenario.Resolved)
+			body := scenario.Provider.buildRequestBody(&scenario.Provider.DefaultConfig, &endpoint.Endpoint{Name: "endpoint-name"}, &scenario.Alert, &endpoint.Result{}, scenario.Resolved)
 			if string(body) != scenario.ExpectedBody {
 				t.Errorf("expected:\n%s\ngot:\n%s", scenario.ExpectedBody, body)
 			}
@@ -173,69 +164,6 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getIntegrationKeyForGroup(t *testing.T) {
-	scenarios := []struct {
-		Name           string
-		Provider       AlertProvider
-		InputGroup     string
-		ExpectedOutput string
-	}{
-		{
-			Name: "provider-no-override-specify-no-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides:      nil,
-			},
-			InputGroup:     "",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-no-override-specify-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides:      nil,
-			},
-			InputGroup:     "group",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-with-override-specify-no-group-should-default",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides: []Override{
-					{
-						Group:          "group",
-						IntegrationKey: "00000000000000000000000000000002",
-					},
-				},
-			},
-			InputGroup:     "",
-			ExpectedOutput: "00000000000000000000000000000001",
-		},
-		{
-			Name: "provider-with-override-specify-group-should-override",
-			Provider: AlertProvider{
-				IntegrationKey: "00000000000000000000000000000001",
-				Overrides: []Override{
-					{
-						Group:          "group",
-						IntegrationKey: "00000000000000000000000000000002",
-					},
-				},
-			},
-			InputGroup:     "group",
-			ExpectedOutput: "00000000000000000000000000000002",
-		},
-	}
-	for _, scenario := range scenarios {
-		t.Run(scenario.Name, func(t *testing.T) {
-			if output := scenario.Provider.getIntegrationKeyForGroup(scenario.InputGroup); output != scenario.ExpectedOutput {
-				t.Errorf("expected %s, got %s", scenario.ExpectedOutput, output)
-			}
-		})
-	}
-}
-
 func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
 		t.Error("expected default alert to be not nil")
@@ -244,3 +172,94 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides:     nil,
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000001"},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000002"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{IntegrationKey: "00000000000000000000000000000001"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{IntegrationKey: "00000000000000000000000000000002"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"integration-key": "00000000000000000000000000000003"}},
+			ExpectedOutput: Config{IntegrationKey: "00000000000000000000000000000003"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.IntegrationKey != scenario.ExpectedOutput.IntegrationKey {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.IntegrationKey, got.IntegrationKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/provider.go

@@ -29,18 +29,26 @@ import (
 
 // AlertProvider is the interface that each provider should implement
 type AlertProvider interface {
-	// IsValid returns whether the provider's configuration is valid
+	// Validate the provider's configuration
-	IsValid() bool
+	Validate() error
+
+	// Send an alert using the provider
+	Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error
 
 	// GetDefaultAlert returns the provider's default alert configuration
 	GetDefaultAlert() *alert.Alert
 
-	// Send an alert using the provider
+	// ValidateOverrides validates the alert's provider override and, if present, the group override
-	Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error
+	ValidateOverrides(group string, alert *alert.Alert) error
 }
 
-// ParseWithDefaultAlert parses an Endpoint alert by using the provider's default alert as a baseline
+type Config[T any] interface {
-func ParseWithDefaultAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
+	Validate() error
+	Merge(override *T)
+}
+
+// MergeProviderDefaultAlertIntoEndpointAlert parses an Endpoint alert by using the provider's default alert as a baseline
+func MergeProviderDefaultAlertIntoEndpointAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
 	if providerDefaultAlert == nil || endpointAlert == nil {
 		return
 	}
@@ -62,14 +70,14 @@ func ParseWithDefaultAlert(providerDefaultAlert, endpointAlert *alert.Alert) {
 }
 
 var (
-	// Validate interface implementation on compile
+	// Validate provider interface implementation on compile
 	_ AlertProvider = (*awsses.AlertProvider)(nil)
 	_ AlertProvider = (*custom.AlertProvider)(nil)
 	_ AlertProvider = (*discord.AlertProvider)(nil)
 	_ AlertProvider = (*email.AlertProvider)(nil)
+	_ AlertProvider = (*gitea.AlertProvider)(nil)
 	_ AlertProvider = (*github.AlertProvider)(nil)
 	_ AlertProvider = (*gitlab.AlertProvider)(nil)
-	_ AlertProvider = (*gitea.AlertProvider)(nil)
 	_ AlertProvider = (*googlechat.AlertProvider)(nil)
 	_ AlertProvider = (*jetbrainsspace.AlertProvider)(nil)
 	_ AlertProvider = (*matrix.AlertProvider)(nil)
@@ -85,4 +93,28 @@ var (
 	_ AlertProvider = (*telegram.AlertProvider)(nil)
 	_ AlertProvider = (*twilio.AlertProvider)(nil)
 	_ AlertProvider = (*zulip.AlertProvider)(nil)
+
+	// Validate config interface implementation on compile
+	_ Config[awsses.Config]         = (*awsses.Config)(nil)
+	_ Config[custom.Config]         = (*custom.Config)(nil)
+	_ Config[discord.Config]        = (*discord.Config)(nil)
+	_ Config[email.Config]          = (*email.Config)(nil)
+	_ Config[gitea.Config]          = (*gitea.Config)(nil)
+	_ Config[github.Config]         = (*github.Config)(nil)
+	_ Config[gitlab.Config]         = (*gitlab.Config)(nil)
+	_ Config[googlechat.Config]     = (*googlechat.Config)(nil)
+	_ Config[jetbrainsspace.Config] = (*jetbrainsspace.Config)(nil)
+	_ Config[matrix.Config]         = (*matrix.Config)(nil)
+	_ Config[mattermost.Config]     = (*mattermost.Config)(nil)
+	_ Config[messagebird.Config]    = (*messagebird.Config)(nil)
+	_ Config[ntfy.Config]           = (*ntfy.Config)(nil)
+	_ Config[opsgenie.Config]       = (*opsgenie.Config)(nil)
+	_ Config[pagerduty.Config]      = (*pagerduty.Config)(nil)
+	_ Config[pushover.Config]       = (*pushover.Config)(nil)
+	_ Config[slack.Config]          = (*slack.Config)(nil)
+	_ Config[teams.Config]          = (*teams.Config)(nil)
+	_ Config[teamsworkflows.Config] = (*teamsworkflows.Config)(nil)
+	_ Config[telegram.Config]       = (*telegram.Config)(nil)
+	_ Config[twilio.Config]         = (*twilio.Config)(nil)
+	_ Config[zulip.Config]          = (*zulip.Config)(nil)
 )

alerting/provider/provider_test.go

@@ -126,7 +126,7 @@ func TestParseWithDefaultAlert(t *testing.T) {
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
-			ParseWithDefaultAlert(scenario.DefaultAlert, scenario.EndpointAlert)
+			MergeProviderDefaultAlertIntoEndpointAlert(scenario.DefaultAlert, scenario.EndpointAlert)
 			if scenario.ExpectedOutputAlert == nil {
 				if scenario.EndpointAlert != nil {
 					t.Fail()

alerting/provider/pushover/pushover.go

@@ -3,6 +3,7 @@ package pushover
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,6 +11,7 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -17,8 +19,13 @@ const (
 	defaultPriority = 0
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Pushover
+var (
-type AlertProvider struct {
+	ErrInvalidApplicationToken = errors.New("application-token must be 30 characters long")
+	ErrInvalidUserKey          = errors.New("user-key must be 30 characters long")
+	ErrInvalidPriority         = errors.New("priority and resolved-priority must be between -2 and 2")
+)
+
+type Config struct {
 	// Key used to authenticate the application sending
 	// See "Your Applications" on the dashboard, or add a new one: https://pushover.net/apps/build
 	ApplicationToken string `yaml:"application-token"`
@@ -41,26 +48,69 @@ type AlertProvider struct {
 	// Sound of the messages (see: https://pushover.net/api#sounds)
 	// default: "" (pushover)
 	Sound string `yaml:"sound,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if cfg.Priority == 0 {
+		cfg.Priority = defaultPriority
+	}
+	if cfg.ResolvedPriority == 0 {
+		cfg.ResolvedPriority = defaultPriority
+	}
+	if len(cfg.ApplicationToken) != 30 {
+		return ErrInvalidApplicationToken
+	}
+	if len(cfg.UserKey) != 30 {
+		return ErrInvalidUserKey
+	}
+	if cfg.Priority < -2 || cfg.Priority > 2 || cfg.ResolvedPriority < -2 || cfg.ResolvedPriority > 2 {
+		return ErrInvalidPriority
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.ApplicationToken) > 0 {
+		cfg.ApplicationToken = override.ApplicationToken
+	}
+	if len(override.UserKey) > 0 {
+		cfg.UserKey = override.UserKey
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+	if override.Priority != 0 {
+		cfg.Priority = override.Priority
+	}
+	if override.ResolvedPriority != 0 {
+		cfg.ResolvedPriority = override.ResolvedPriority
+	}
+	if len(override.Sound) > 0 {
+		cfg.Sound = override.Sound
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Pushover
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if provider.Priority == 0 {
+	return provider.DefaultConfig.Validate()
-		provider.Priority = defaultPriority
-	}
-	if provider.ResolvedPriority == 0 {
-		provider.ResolvedPriority = defaultPriority
-	}
-	return len(provider.ApplicationToken) == 30 && len(provider.UserKey) == 30 && provider.Priority >= -2 && provider.Priority <= 2 && provider.ResolvedPriority >= -2 && provider.ResolvedPriority <= 2
 }
 
 // Send an alert using the provider
 // Reference doc for pushover: https://pushover.net/api
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
 	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
 	if err != nil {
 		return err
@@ -88,38 +138,51 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
 	} else {
 		message = fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
 	}
+	priority := cfg.Priority
+	if resolved {
+		priority = cfg.ResolvedPriority
+	}
 	body, _ := json.Marshal(Body{
-		Token:    provider.ApplicationToken,
+		Token:    cfg.ApplicationToken,
-		User:     provider.UserKey,
+		User:     cfg.UserKey,
-		Title:    provider.Title,
+		Title:    cfg.Title,
 		Message:  message,
-		Priority: provider.priority(resolved),
+		Priority: priority,
-		Sound:    provider.Sound,
+		Sound:    cfg.Sound,
 	})
 	return body
 }
 
-func (provider *AlertProvider) priority(resolved bool) int {
-	if resolved && provider.ResolvedPriority == 0 {
-		return defaultPriority
-	}
-	if !resolved && provider.Priority == 0 {
-		return defaultPriority
-	}
-	if resolved {
-		return provider.ResolvedPriority
-	}
-	return provider.Priority
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/pushover/pushover_test.go

@@ -12,31 +12,38 @@ import (
 )
 
 func TestPushoverAlertProvider_IsValid(t *testing.T) {
+	t.Run("empty-invalid-provider", func(t *testing.T) {
 		invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
+	})
+	t.Run("valid-provider", func(t *testing.T) {
 		validProvider := AlertProvider{
+			DefaultConfig: Config{
 				ApplicationToken: "aTokenWithLengthOf30characters",
 				UserKey:          "aTokenWithLengthOf30characters",
 				Title:            "Gatus Notification",
 				Priority:         1,
 				ResolvedPriority: 1,
+			},
 		}
-	if !validProvider.IsValid() {
+		if err := validProvider.Validate(); err != nil {
 			t.Error("provider should've been valid")
 		}
-}
+	})
-
+	t.Run("invalid-provider", func(t *testing.T) {
-func TestPushoverAlertProvider_IsInvalid(t *testing.T) {
 		invalidProvider := AlertProvider{
+			DefaultConfig: Config{
 				ApplicationToken: "aTokenWithLengthOfMoreThan30characters",
 				UserKey:          "aTokenWithLengthOfMoreThan30characters",
 				Priority:         5,
+			},
 		}
-	if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider should've been invalid")
 		}
+	})
 }
 
 func TestAlertProvider_Send(t *testing.T) {
@@ -53,7 +60,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -63,7 +70,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -73,7 +80,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +90,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -129,28 +136,28 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters1", UserKey: "TokenWithLengthOf30Characters4"},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters1", UserKey: "TokenWithLengthOf30Characters4"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters1\",\"user\":\"TokenWithLengthOf30Characters4\",\"message\":\"TRIGGERED: endpoint-name - description-1\",\"priority\":0}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"RESOLVED: endpoint-name - description-2\",\"priority\":2}",
 		},
 		{
 			Name:         "resolved-priority",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 0},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 0}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"RESOLVED: endpoint-name - description-2\",\"priority\":0}",
 		},
 		{
 			Name:         "with-sound",
-			Provider:     AlertProvider{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2, Sound: "falling"},
+			Provider:     AlertProvider{DefaultConfig: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters5", Title: "Gatus Notifications", Priority: 2, ResolvedPriority: 2, Sound: "falling"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"token\":\"TokenWithLengthOf30Characters2\",\"user\":\"TokenWithLengthOf30Characters5\",\"title\":\"Gatus Notifications\",\"message\":\"RESOLVED: endpoint-name - description-2\",\"priority\":2,\"sound\":\"falling\"}",
@@ -159,6 +166,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -188,3 +196,50 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+			},
+			InputGroup:     "",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{ApplicationToken: "aTokenWithLengthOf30characters", UserKey: "aTokenWithLengthOf30characters"},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"application-token": "TokenWithLengthOf30Characters2", "user-key": "TokenWithLengthOf30Characters3"}},
+			ExpectedOutput: Config{ApplicationToken: "TokenWithLengthOf30Characters2", UserKey: "TokenWithLengthOf30Characters3"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.ApplicationToken != scenario.ExpectedOutput.ApplicationToken {
+				t.Errorf("expected application token to be %s, got %s", scenario.ExpectedOutput.ApplicationToken, got.ApplicationToken)
+			}
+			if got.UserKey != scenario.ExpectedOutput.UserKey {
+				t.Errorf("expected user key to be %s, got %s", scenario.ExpectedOutput.UserKey, got.UserKey)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/slack/slack.go

@@ -3,6 +3,7 @@ package slack
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,13 +11,38 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"` // Slack webhook URL
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Slack
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"` // Slack webhook URL
+	DefaultConfig Config `yaml:",inline"`
+
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
 }
@@ -24,27 +50,31 @@ type AlertProvider struct {
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
 	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -126,19 +156,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/slack/slack_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "https://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "https://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
+				Config: Config{WebhookURL: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -227,64 +227,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/teams/teams.go

@@ -3,6 +3,7 @@ package teams
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,54 +11,85 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Teams
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
-
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -84,7 +116,7 @@ type Section struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message, color string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
@@ -111,7 +143,7 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		Type:       "MessageCard",
 		Context:    "http://schema.org/extensions",
 		ThemeColor: color,
-		Title:      provider.Title,
+		Title:      cfg.Title,
 		Text:       message + description,
 	}
 	if len(body.Title) == 0 {
@@ -127,19 +159,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/teams/teams_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
+				Config: Config{WebhookURL: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -180,6 +180,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				}
 			}
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{ConditionResults: conditionResults},
@@ -205,64 +206,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/teamsworkflows/teamsworkflows.go

@@ -3,6 +3,7 @@ package teamsworkflows
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,46 +11,74 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrWebhookURLNotSet       = errors.New("webhook-url not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	WebhookURL string `yaml:"webhook-url"`
+	Title      string `yaml:"title,omitempty"` // Title of the message that will be sent
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.WebhookURL) == 0 {
+		return ErrWebhookURLNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.WebhookURL) > 0 {
+		cfg.WebhookURL = override.WebhookURL
+	}
+	if len(override.Title) > 0 {
+		cfg.Title = override.Title
+	}
+}
+
 // AlertProvider is the configuration necessary for sending an alert using Teams
 type AlertProvider struct {
-	WebhookURL string `yaml:"webhook-url"`
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
-
-	// Title is the title of the message that will be sent
-	Title string `yaml:"title,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
 type Override struct {
 	Group  string `yaml:"group"`
-	WebhookURL string `yaml:"webhook-url"`
+	Config `yaml:",inline"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-				return false
+				return ErrDuplicateGroupOverride
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return len(provider.WebhookURL) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(ep.Group), buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, cfg.WebhookURL, buffer)
 	if err != nil {
 		return err
 	}
@@ -106,7 +135,7 @@ type Fact struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	var themeColor string
 	if resolved {
@@ -119,8 +148,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 
 	// Configure default title if it's not provided
 	title := "⛑ Gatus"
-	if provider.Title != "" {
+	if cfg.Title != "" {
-		title = provider.Title
+		title = cfg.Title
 	}
 
 	// Build the facts from the condition results
@@ -189,19 +218,38 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 	return bodyAsJSON
 }
 
-// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
-func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
-	if provider.Overrides != nil {
-		for _, override := range provider.Overrides {
-			if group == override.Group {
-				return override.WebhookURL
-			}
-		}
-	}
-	return provider.WebhookURL
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/teamsworkflows/teamsworkflows_test.go

@@ -11,50 +11,50 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	invalidProvider := AlertProvider{WebhookURL: ""}
+	invalidProvider := AlertProvider{DefaultConfig: Config{WebhookURL: ""}}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
-		t.Error("provider should've been valid")
+		t.Error("provider should've been valid, got", err.Error())
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_ValidateWithOverride(t *testing.T) {
 	providerWithInvalidOverrideGroup := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "",
 			},
 		},
 	}
-	if providerWithInvalidOverrideGroup.IsValid() {
+	if err := providerWithInvalidOverrideGroup.Validate(); err == nil {
 		t.Error("provider Group shouldn't have been valid")
 	}
 	providerWithInvalidOverrideTo := AlertProvider{
 		Overrides: []Override{
 			{
-				WebhookURL: "",
+				Config: Config{WebhookURL: ""},
 				Group:  "group",
 			},
 		},
 	}
-	if providerWithInvalidOverrideTo.IsValid() {
+	if err := providerWithInvalidOverrideTo.Validate(); err == nil {
 		t.Error("provider integration key shouldn't have been valid")
 	}
 	providerWithValidOverride := AlertProvider{
-		WebhookURL: "http://example.com",
+		DefaultConfig: Config{WebhookURL: "http://example.com"},
 		Overrides: []Override{
 			{
-				WebhookURL: "http://example.com",
+				Config: Config{WebhookURL: "http://example.com"},
 				Group:  "group",
 			},
 		},
 	}
-	if !providerWithValidOverride.IsValid() {
+	if err := providerWithValidOverride.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
@@ -73,7 +73,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -83,7 +83,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -93,7 +93,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -103,7 +103,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{WebhookURL: "http://example.com"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -180,6 +180,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				}
 			}
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{ConditionResults: conditionResults},
@@ -205,64 +206,92 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+func TestAlertProvider_GetConfig(t *testing.T) {
-	tests := []struct {
+	scenarios := []struct {
 		Name           string
 		Provider       AlertProvider
 		InputGroup     string
-		ExpectedOutput string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
 	}{
 		{
 			Name: "provider-no-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-no-override-specify-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides:     nil,
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-no-group-should-default",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://example01.com"},
 					},
 				},
 			},
 			InputGroup:     "",
-			ExpectedOutput: "http://example.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://example.com"},
 		},
 		{
 			Name: "provider-with-override-specify-group-should-override",
 			Provider: AlertProvider{
-				WebhookURL: "http://example.com",
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
 				Overrides: []Override{
 					{
 						Group:  "group",
-						WebhookURL: "http://example01.com",
+						Config: Config{WebhookURL: "http://group-example.com"},
 					},
 				},
 			},
 			InputGroup:     "group",
-			ExpectedOutput: "http://example01.com",
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{WebhookURL: "http://group-example.com"},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{WebhookURL: "http://example.com"},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{WebhookURL: "http://group-example.com"},
+					},
+				},
+			},
+			InputGroup:     "group",
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"webhook-url": "http://alert-example.com"}},
+			ExpectedOutput: Config{WebhookURL: "http://alert-example.com"},
 		},
 	}
-	for _, tt := range tests {
+	for _, scenario := range scenarios {
-		t.Run(tt.Name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
-				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.WebhookURL != scenario.ExpectedOutput.WebhookURL {
+				t.Errorf("expected webhook URL to be %s, got %s", scenario.ExpectedOutput.WebhookURL, got.WebhookURL)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

alerting/provider/telegram/telegram.go

@@ -3,6 +3,7 @@ package telegram
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,66 +11,97 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-const defaultAPIURL = "https://api.telegram.org"
+const defaultApiUrl = "https://api.telegram.org"
+
+var (
+	ErrTokenNotSet            = errors.New("token not set")
+	ErrIDNotSet               = errors.New("id not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	Token  string `yaml:"token"`
+	ID     string `yaml:"id"`
+	ApiUrl string `yaml:"api-url"`
+
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.ApiUrl) == 0 {
+		cfg.ApiUrl = defaultApiUrl
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	if len(cfg.ID) == 0 {
+		return ErrIDNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if override.ClientConfig != nil {
+		cfg.ClientConfig = override.ClientConfig
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.ID) > 0 {
+		cfg.ID = override.ID
+	}
+	if len(override.ApiUrl) > 0 {
+		cfg.ApiUrl = override.ApiUrl
+	}
+}
 
 // AlertProvider is the configuration necessary for sending an alert using Telegram
 type AlertProvider struct {
-	Token  string `yaml:"token"`
+	DefaultConfig Config `yaml:",inline"`
-	ID     string `yaml:"id"`
-	APIURL string `yaml:"api-url"`
-
-	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
-	// Overrides is a list of Overrid that may be prioritized over the default configuration
+	// Overrides is a list of overrides that may be prioritized over the default configuration
 	Overrides []*Override `yaml:"overrides,omitempty"`
 }
 
 // Override is a configuration that may be prioritized over the default configuration
 type Override struct {
-	group string `yaml:"group"`
+	Group  string `yaml:"group"`
-	token string `yaml:"token"`
+	Config `yaml:",inline"`
-	id    string `yaml:"id"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	if provider.ClientConfig == nil {
+	registeredGroups := make(map[string]bool)
-		provider.ClientConfig = client.GetDefaultConfig()
+	if provider.Overrides != nil {
-	}
-
-	registerGroups := make(map[string]bool)
 		for _, override := range provider.Overrides {
-		if len(override.group) == 0 {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-			return false
+				return ErrDuplicateGroupOverride
 			}
-		if _, ok := registerGroups[override.group]; ok {
+			registeredGroups[override.Group] = true
-			return false
 		}
-		registerGroups[override.group] = true
 	}
-
+	return provider.DefaultConfig.Validate()
-	return len(provider.Token) > 0 && len(provider.ID) > 0
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	apiURL := provider.APIURL
+	if err != nil {
-	if apiURL == "" {
+		return err
-		apiURL = defaultAPIURL
 	}
-	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/bot%s/sendMessage", apiURL, provider.getTokenForGroup(ep.Group)), buffer)
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/bot%s/sendMessage", cfg.ApiUrl, cfg.Token), buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/json")
-	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	response, err := client.GetHTTPClient(cfg.ClientConfig).Do(request)
 	if err != nil {
 		return err
 	}
@@ -81,15 +113,6 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return err
 }
 
-func (provider *AlertProvider) getTokenForGroup(group string) string {
-	for _, override := range provider.Overrides {
-		if override.group == group && len(override.token) > 0 {
-			return override.token
-		}
-	}
-	return provider.Token
-}
-
 type Body struct {
 	ChatID    string `json:"chat_id"`
 	Text      string `json:"text"`
@@ -97,7 +120,7 @@ type Body struct {
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("An alert for *%s* has been resolved:\n—\n    _healthcheck passing successfully %d time(s) in a row_\n—  ", ep.DisplayName(), alert.SuccessThreshold)
@@ -124,23 +147,45 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		text = fmt.Sprintf("⛑ *Gatus* \n%s%s", message, formattedConditionResults)
 	}
 	bodyAsJSON, _ := json.Marshal(Body{
-		ChatID:    provider.getIDForGroup(ep.Group),
+		ChatID:    cfg.ID,
 		Text:      text,
 		ParseMode: "MARKDOWN",
 	})
 	return bodyAsJSON
 }
 
-func (provider *AlertProvider) getIDForGroup(group string) string {
-	for _, override := range provider.Overrides {
-		if override.group == group && len(override.id) > 0 {
-			return override.id
-		}
-	}
-	return provider.ID
-}
-
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/telegram/telegram_test.go

@@ -11,87 +11,36 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertDefaultProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
 	t.Run("invalid-provider", func(t *testing.T) {
-		invalidProvider := AlertProvider{Token: "", ID: ""}
+		invalidProvider := AlertProvider{DefaultConfig: Config{Token: "", ID: ""}}
-		if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
 	})
 	t.Run("valid-provider", func(t *testing.T) {
-		validProvider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}
+		validProvider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}}
-		if validProvider.ClientConfig != nil {
+		if err := validProvider.Validate(); err != nil {
-			t.Error("provider client config should have been nil prior to IsValid() being executed")
-		}
-		if !validProvider.IsValid() {
 			t.Error("provider should've been valid")
 		}
-		if validProvider.ClientConfig == nil {
-			t.Error("provider client config should have been set after IsValid() was executed")
-		}
 	})
-}
-
-func TestAlertProvider_IsValidWithOverrides(t *testing.T) {
 	t.Run("invalid-provider-override-nonexist-group", func(t *testing.T) {
-		invalidProvider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{token: "token", id: "id"}}}
+		invalidProvider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Config: Config{Token: "token", ID: "id"}}}}
-		if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
 	})
 	t.Run("invalid-provider-override-duplicate-group", func(t *testing.T) {
-		invalidProvider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{group: "group1", token: "token", id: "id"}, {group: "group1", id: "id2"}}}
+		invalidProvider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group1", Config: Config{Token: "token", ID: "id"}}, {Group: "group1", Config: Config{ID: "id2"}}}}
-		if invalidProvider.IsValid() {
+		if err := invalidProvider.Validate(); err == nil {
 			t.Error("provider shouldn't have been valid")
 		}
 	})
-	t.Run("valid-provider", func(t *testing.T) {
+	t.Run("valid-provider-with-overrides", func(t *testing.T) {
-		validProvider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{group: "group", token: "token", id: "id"}}}
+		validProvider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group", Config: Config{Token: "token", ID: "id"}}}}
-		if validProvider.ClientConfig != nil {
+		if err := validProvider.Validate(); err != nil {
-			t.Error("provider client config should have been nil prior to IsValid() being executed")
-		}
-		if !validProvider.IsValid() {
 			t.Error("provider should've been valid")
 		}
-		if validProvider.ClientConfig == nil {
-			t.Error("provider client config should have been set after IsValid() was executed")
-		}
-	})
-}
-
-func TestAlertProvider_getTokenAndIDForGroup(t *testing.T) {
-	t.Run("get-token-with-override", func(t *testing.T) {
-		provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{group: "group", token: "overrideToken", id: "overrideID"}}}
-		token := provider.getTokenForGroup("group")
-		if token != "overrideToken" {
-			t.Error("token should have been 'overrideToken'")
-		}
-		id := provider.getIDForGroup("group")
-		if id != "overrideID" {
-			t.Error("id should have been 'overrideID'")
-		}
-	})
-	t.Run("get-default-token-with-overridden-id", func(t *testing.T) {
-		provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{group: "group", id: "overrideID"}}}
-		token := provider.getTokenForGroup("group")
-		if token != provider.Token {
-			t.Error("token should have been the default token")
-		}
-		id := provider.getIDForGroup("group")
-		if id != "overrideID" {
-			t.Error("id should have been 'overrideID'")
-		}
-	})
-	t.Run("get-default-token-with-overridden-token", func(t *testing.T) {
-		provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678", Overrides: []*Override{{group: "group", token: "overrideToken"}}}
-		token := provider.getTokenForGroup("group")
-		if token != "overrideToken" {
-			t.Error("token should have been 'overrideToken'")
-		}
-		id := provider.getIDForGroup("group")
-		if id != provider.ID {
-			t.Error("id should have been the default id")
-		}
 	})
 }
 
@@ -109,7 +58,7 @@ func TestAlertProvider_Send(t *testing.T) {
 	}{
 		{
 			Name:     "triggered",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ID: "123", Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -119,7 +68,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "triggered-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ID: "123", Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"}},
 			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: false,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -129,7 +78,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ID: "123", Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -139,7 +88,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		},
 		{
 			Name:     "resolved-error",
-			Provider: AlertProvider{},
+			Provider: AlertProvider{DefaultConfig: Config{ID: "123", Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"}},
 			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved: true,
 			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
@@ -185,14 +134,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{ID: "123"},
+			Provider:     AlertProvider{DefaultConfig: Config{ID: "123"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "{\"chat_id\":\"123\",\"text\":\"⛑ *Gatus* \\nAn alert for *endpoint-name* has been triggered:\\n—\\n    _healthcheck failed 3 time(s) in a row_\\n—   \\n*Description* \\n_description-1_  \\n\\n*Condition results*\\n❌ - `[CONNECTED] == true`\\n❌ - `[STATUS] == 200`\\n\",\"parse_mode\":\"MARKDOWN\"}",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{ID: "123"},
+			Provider:     AlertProvider{DefaultConfig: Config{ID: "123"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"chat_id\":\"123\",\"text\":\"⛑ *Gatus* \\nAn alert for *endpoint-name* has been resolved:\\n—\\n    _healthcheck passing successfully 5 time(s) in a row_\\n—   \\n*Description* \\n_description-2_  \\n\\n*Condition results*\\n✅ - `[CONNECTED] == true`\\n✅ - `[STATUS] == 200`\\n\",\"parse_mode\":\"MARKDOWN\"}",
@@ -200,7 +149,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 		{
 			Name:         "resolved-with-no-conditions",
 			NoConditions: true,
-			Provider:     AlertProvider{ID: "123"},
+			Provider:     AlertProvider{DefaultConfig: Config{ID: "123"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "{\"chat_id\":\"123\",\"text\":\"⛑ *Gatus* \\nAn alert for *endpoint-name* has been resolved:\\n—\\n    _healthcheck passing successfully 5 time(s) in a row_\\n—   \\n*Description* \\n_description-2_  \\n\",\"parse_mode\":\"MARKDOWN\"}",
@@ -216,6 +165,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 				}
 			}
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{ConditionResults: conditionResults},
@@ -240,3 +190,63 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	t.Run("get-token-with-override", func(t *testing.T) {
+		provider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group", Config: Config{Token: "groupToken", ID: "overrideID"}}}}
+		cfg, err := provider.GetConfig("group", &alert.Alert{})
+		if err != nil {
+			t.Error("expected no error, got", err)
+		}
+		if cfg.Token != "groupToken" {
+			t.Error("token should have been 'groupToken'")
+		}
+		if cfg.ID != "overrideID" {
+			t.Error("id should have been 'overrideID'")
+		}
+	})
+	t.Run("get-default-token-with-overridden-id", func(t *testing.T) {
+		provider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group", Config: Config{ID: "overrideID"}}}}
+		cfg, err := provider.GetConfig("group", &alert.Alert{})
+		if err != nil {
+			t.Error("expected no error, got", err)
+		}
+		if cfg.Token != provider.DefaultConfig.Token {
+			t.Error("token should have been the default token")
+		}
+		if cfg.ID != "overrideID" {
+			t.Error("id should have been 'overrideID'")
+		}
+	})
+	t.Run("get-default-token-with-overridden-token", func(t *testing.T) {
+		provider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group", Config: Config{Token: "groupToken"}}}}
+		cfg, err := provider.GetConfig("group", &alert.Alert{})
+		if err != nil {
+			t.Error("expected no error, got", err)
+		}
+		if cfg.Token != "groupToken" {
+			t.Error("token should have been 'groupToken'")
+		}
+		if cfg.ID != provider.DefaultConfig.ID {
+			t.Error("id should have been the default id")
+		}
+	})
+	t.Run("get-default-token-with-overridden-token-and-alert-token-override", func(t *testing.T) {
+		provider := AlertProvider{DefaultConfig: Config{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}, Overrides: []*Override{{Group: "group", Config: Config{Token: "groupToken"}}}}
+		alert := &alert.Alert{ProviderOverride: map[string]any{"token": "alertToken"}}
+		cfg, err := provider.GetConfig("group", alert)
+		if err != nil {
+			t.Error("expected no error, got", err)
+		}
+		if cfg.Token != "alertToken" {
+			t.Error("token should have been 'alertToken'")
+		}
+		if cfg.ID != provider.DefaultConfig.ID {
+			t.Error("id should have been the default id")
+		}
+		// Test ValidateOverrides as well, since it really just calls GetConfig
+		if err = provider.ValidateOverrides("group", alert); err != nil {
+			t.Errorf("unexpected error: %s", err)
+		}
+	})
+}

alerting/provider/twilio/twilio.go

@@ -3,6 +3,7 @@ package twilio
 import (
 	"bytes"
 	"encoding/base64"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -11,33 +12,80 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
 )
 
-// AlertProvider is the configuration necessary for sending an alert using Twilio
+var (
-type AlertProvider struct {
+	ErrSIDNotSet   = errors.New("sid not set")
+	ErrTokenNotSet = errors.New("token not set")
+	ErrFromNotSet  = errors.New("from not set")
+	ErrToNotSet    = errors.New("to not set")
+)
+
+type Config struct {
 	SID   string `yaml:"sid"`
 	Token string `yaml:"token"`
 	From  string `yaml:"from"`
 	To    string `yaml:"to"`
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.SID) == 0 {
+		return ErrSIDNotSet
+	}
+	if len(cfg.Token) == 0 {
+		return ErrTokenNotSet
+	}
+	if len(cfg.From) == 0 {
+		return ErrFromNotSet
+	}
+	if len(cfg.To) == 0 {
+		return ErrToNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.SID) > 0 {
+		cfg.SID = override.SID
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.From) > 0 {
+		cfg.From = override.From
+	}
+	if len(override.To) > 0 {
+		cfg.To = override.To
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Twilio
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
-// IsValid returns whether the provider's configuration is valid
+// Validate the provider's configuration
-func (provider *AlertProvider) IsValid() bool {
+func (provider *AlertProvider) Validate() error {
-	return len(provider.Token) > 0 && len(provider.SID) > 0 && len(provider.From) > 0 && len(provider.To) > 0
+	return provider.DefaultConfig.Validate()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(ep, alert, result, resolved)))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json", provider.SID), buffer)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(cfg, ep, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json", cfg.SID), buffer)
 	if err != nil {
 		return err
 	}
 	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	request.Header.Set("Authorization", fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(provider.SID+":"+provider.Token))))
+	request.Header.Set("Authorization", fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(cfg.SID+":"+cfg.Token))))
 	response, err := client.GetHTTPClient(nil).Do(request)
 	if err != nil {
 		return err
@@ -51,7 +99,7 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 }
 
 // buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) string {
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) string {
 	var message string
 	if resolved {
 		message = fmt.Sprintf("RESOLVED: %s - %s", ep.DisplayName(), alert.GetDescription())
@@ -59,8 +107,8 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 		message = fmt.Sprintf("TRIGGERED: %s - %s", ep.DisplayName(), alert.GetDescription())
 	}
 	return url.Values{
-		"To":   {provider.To},
+		"To":   {cfg.To},
-		"From": {provider.From},
+		"From": {cfg.From},
 		"Body": {message},
 	}.Encode()
 }
@@ -69,3 +117,25 @@ func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *al
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/twilio/twilio_test.go

@@ -1,28 +1,110 @@
 package twilio
 
 import (
+	"net/http"
 	"testing"
 
 	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"github.com/TwiN/gatus/v5/test"
 )
 
 func TestTwilioAlertProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{}
-	if invalidProvider.IsValid() {
+	if err := invalidProvider.Validate(); err == nil {
 		t.Error("provider shouldn't have been valid")
 	}
 	validProvider := AlertProvider{
+		DefaultConfig: Config{
 			SID:   "1",
 			Token: "1",
 			From:  "1",
 			To:    "1",
+		},
 	}
-	if !validProvider.IsValid() {
+	if err := validProvider.Validate(); err != nil {
 		t.Error("provider should've been valid")
 	}
 }
 
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&endpoint.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&endpoint.Result{
+					ConditionResults: []*endpoint.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
 func TestAlertProvider_buildRequestBody(t *testing.T) {
 	firstDescription := "description-1"
 	secondDescription := "description-2"
@@ -35,14 +117,14 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	}{
 		{
 			Name:         "triggered",
-			Provider:     AlertProvider{SID: "1", Token: "2", From: "3", To: "4"},
+			Provider:     AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
 			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     false,
 			ExpectedBody: "Body=TRIGGERED%3A+endpoint-name+-+description-1&From=3&To=4",
 		},
 		{
 			Name:         "resolved",
-			Provider:     AlertProvider{SID: "1", Token: "2", From: "3", To: "4"},
+			Provider:     AlertProvider{DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"}},
 			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
 			Resolved:     true,
 			ExpectedBody: "Body=RESOLVED%3A+endpoint-name+-+description-2&From=3&To=4",
@@ -51,6 +133,7 @@ func TestAlertProvider_buildRequestBody(t *testing.T) {
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
 			body := scenario.Provider.buildRequestBody(
+				&scenario.Provider.DefaultConfig,
 				&endpoint.Endpoint{Name: "endpoint-name"},
 				&scenario.Alert,
 				&endpoint.Result{
@@ -76,3 +159,53 @@ func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 		t.Error("expected default alert to be nil")
 	}
 }
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-override-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"},
+			},
+			InputAlert:     alert.Alert{},
+			ExpectedOutput: Config{SID: "1", Token: "2", From: "3", To: "4"},
+		},
+		{
+			Name: "provider-with-alert-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{SID: "1", Token: "2", From: "3", To: "4"},
+			},
+			InputAlert:     alert.Alert{ProviderOverride: map[string]any{"sid": "5", "token": "6", "from": "7", "to": "8"}},
+			ExpectedOutput: Config{SID: "5", Token: "6", From: "7", To: "8"},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig("", &scenario.InputAlert)
+			if err != nil {
+				t.Error("expected no error, got:", err.Error())
+			}
+			if got.SID != scenario.ExpectedOutput.SID {
+				t.Errorf("expected SID to be %s, got %s", scenario.ExpectedOutput.SID, got.SID)
+			}
+			if got.Token != scenario.ExpectedOutput.Token {
+				t.Errorf("expected token to be %s, got %s", scenario.ExpectedOutput.Token, got.Token)
+			}
+			if got.From != scenario.ExpectedOutput.From {
+				t.Errorf("expected from to be %s, got %s", scenario.ExpectedOutput.From, got.From)
+			}
+			if got.To != scenario.ExpectedOutput.To {
+				t.Errorf("expected to to be %s, got %s", scenario.ExpectedOutput.To, got.To)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides("", &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
+			}
+		})
+	}
+}

alerting/provider/zulip/zulip.go

@@ -2,6 +2,7 @@ package zulip
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -10,108 +11,99 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	ErrBotEmailNotSet         = errors.New("bot-email not set")
+	ErrBotAPIKeyNotSet        = errors.New("bot-api-key not set")
+	ErrDomainNotSet           = errors.New("domain not set")
+	ErrChannelIDNotSet        = errors.New("channel-id not set")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
 )
 
 type Config struct {
-	// BotEmail is the email of the bot user
+	BotEmail  string `yaml:"bot-email"`   // Email of the bot user
-	BotEmail string `yaml:"bot-email"`
+	BotAPIKey string `yaml:"bot-api-key"` // API key of the bot user
-	// BotAPIKey is the API key of the bot user
+	Domain    string `yaml:"domain"`      // Domain of the Zulip server
-	BotAPIKey string `yaml:"bot-api-key"`
+	ChannelID string `yaml:"channel-id"`  // ID of the channel to send the message to
-	// Domain is the domain of the Zulip server
+}
-	Domain string `yaml:"domain"`
+
-	// ChannelID is the ID of the channel to send the message to
+func (cfg *Config) Validate() error {
-	ChannelID string `yaml:"channel-id"`
+	if len(cfg.BotEmail) == 0 {
+		return ErrBotEmailNotSet
+	}
+	if len(cfg.BotAPIKey) == 0 {
+		return ErrBotAPIKeyNotSet
+	}
+	if len(cfg.Domain) == 0 {
+		return ErrDomainNotSet
+	}
+	if len(cfg.ChannelID) == 0 {
+		return ErrChannelIDNotSet
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.BotEmail) > 0 {
+		cfg.BotEmail = override.BotEmail
+	}
+	if len(override.BotAPIKey) > 0 {
+		cfg.BotAPIKey = override.BotAPIKey
+	}
+	if len(override.Domain) > 0 {
+		cfg.Domain = override.Domain
+	}
+	if len(override.ChannelID) > 0 {
+		cfg.ChannelID = override.ChannelID
+	}
 }
 
 // AlertProvider is the configuration necessary for sending an alert using Zulip
 type AlertProvider struct {
-	Config `yaml:",inline"`
+	DefaultConfig Config `yaml:",inline"`
+
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
 	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
 	// Overrides is a list of Override that may be prioritized over the default configuration
 	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
 type Override struct {
-	Config
 	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
 }
 
-func (provider *AlertProvider) validateConfig(conf *Config) bool {
+// Validate the provider's configuration
-	return len(conf.BotEmail) > 0 && len(conf.BotAPIKey) > 0 && len(conf.Domain) > 0 && len(conf.ChannelID) > 0
+func (provider *AlertProvider) Validate() error {
-}
-
-// IsValid returns whether the provider's configuration is valid
-func (provider *AlertProvider) IsValid() bool {
 	registeredGroups := make(map[string]bool)
 	if provider.Overrides != nil {
 		for _, override := range provider.Overrides {
-			isAlreadyRegistered := registeredGroups[override.Group]
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" {
-			if isAlreadyRegistered || override.Group == "" || !provider.validateConfig(&override.Config) {
+				return ErrDuplicateGroupOverride
-				return false
 			}
 			registeredGroups[override.Group] = true
 		}
 	}
-	return provider.validateConfig(&provider.Config)
+	return provider.DefaultConfig.Validate()
-}
-
-// getChannelIdForGroup returns the channel ID for the provided group
-func (provider *AlertProvider) getChannelIdForGroup(group string) string {
-	for _, override := range provider.Overrides {
-		if override.Group == group {
-			return override.ChannelID
-		}
-	}
-	return provider.ChannelID
-}
-
-// buildRequestBody builds the request body for the provider
-func (provider *AlertProvider) buildRequestBody(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) string {
-	var message string
-	if resolved {
-		message = fmt.Sprintf("An alert for **%s** has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
-	} else {
-		message = fmt.Sprintf("An alert for **%s** has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
-	}
-
-	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
-		message += "\n> " + alertDescription + "\n"
-	}
-
-	for _, conditionResult := range result.ConditionResults {
-		var prefix string
-		if conditionResult.Success {
-			prefix = ":check:"
-		} else {
-			prefix = ":cross_mark:"
-		}
-		message += fmt.Sprintf("\n%s - `%s`", prefix, conditionResult.Condition)
-	}
-
-	postData := map[string]string{
-		"type":    "channel",
-		"to":      provider.getChannelIdForGroup(ep.Group),
-		"topic":   "Gatus",
-		"content": message,
-	}
-	bodyParams := url.Values{}
-	for field, value := range postData {
-		bodyParams.Add(field, value)
-	}
-	return bodyParams.Encode()
 }
 
 // Send an alert using the provider
 func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
-	buffer := bytes.NewBufferString(provider.buildRequestBody(ep, alert, result, resolved))
+	cfg, err := provider.GetConfig(ep.Group, alert)
-	zulipEndpoint := fmt.Sprintf("https://%s/api/v1/messages", provider.Domain)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBufferString(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	zulipEndpoint := fmt.Sprintf("https://%s/api/v1/messages", cfg.Domain)
 	request, err := http.NewRequest(http.MethodPost, zulipEndpoint, buffer)
 	if err != nil {
 		return err
 	}
-	request.SetBasicAuth(provider.BotEmail, provider.BotAPIKey)
+	request.SetBasicAuth(cfg.BotEmail, cfg.BotAPIKey)
 	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	request.Header.Set("User-Agent", "Gatus")
 	response, err := client.GetHTTPClient(nil).Do(request)
@@ -126,7 +118,66 @@ func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, r
 	return nil
 }
 
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) string {
+	var message string
+	if resolved {
+		message = fmt.Sprintf("An alert for **%s** has been resolved after passing successfully %d time(s) in a row", ep.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("An alert for **%s** has been triggered due to having failed %d time(s) in a row", ep.DisplayName(), alert.FailureThreshold)
+	}
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		message += "\n> " + alertDescription + "\n"
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = ":check:"
+		} else {
+			prefix = ":cross_mark:"
+		}
+		message += fmt.Sprintf("\n%s - `%s`", prefix, conditionResult.Condition)
+	}
+	return url.Values{
+		"type":    {"channel"},
+		"to":      {cfg.ChannelID},
+		"topic":   {"Gatus"},
+		"content": {message},
+	}.Encode()
+}
+
 // GetDefaultAlert returns the provider's default alert configuration
 func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}

alerting/provider/zulip/zulip_test.go

@@ -1,6 +1,7 @@
 package zulip
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -12,237 +13,84 @@ import (
 	"github.com/TwiN/gatus/v5/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertProvider_Validate(t *testing.T) {
-	testCase := []struct {
+	scenarios := []struct {
-		name          string
+		Name          string
-		alertProvider AlertProvider
+		AlertProvider AlertProvider
-		expected      bool
+		ExpectedError error
 	}{
 		{
-			name:          "Empty provider",
+			Name:          "Empty provider",
-			alertProvider: AlertProvider{},
+			AlertProvider: AlertProvider{},
-			expected:      false,
+			ExpectedError: ErrBotEmailNotSet,
 		},
 		{
-			name: "Empty channel id",
+			Name: "Empty channel id",
-			alertProvider: AlertProvider{
+			AlertProvider: AlertProvider{
-				Config: Config{
+				DefaultConfig: Config{
 					BotEmail:  "something",
 					BotAPIKey: "something",
 					Domain:    "something",
 				},
 			},
-			expected: false,
+			ExpectedError: ErrChannelIDNotSet,
 		},
 		{
-			name: "Empty domain",
+			Name: "Empty domain",
-			alertProvider: AlertProvider{
+			AlertProvider: AlertProvider{
-				Config: Config{
+				DefaultConfig: Config{
 					BotEmail:  "something",
 					BotAPIKey: "something",
 					ChannelID: "something",
 				},
 			},
-			expected: false,
+			ExpectedError: ErrDomainNotSet,
 		},
 		{
-			name: "Empty bot api key",
+			Name: "Empty bot api key",
-			alertProvider: AlertProvider{
+			AlertProvider: AlertProvider{
-				Config: Config{
+				DefaultConfig: Config{
 					BotEmail:  "something",
 					Domain:    "something",
 					ChannelID: "something",
 				},
 			},
-			expected: false,
+			ExpectedError: ErrBotAPIKeyNotSet,
 		},
 		{
-			name: "Empty bot email",
+			Name: "Empty bot email",
-			alertProvider: AlertProvider{
+			AlertProvider: AlertProvider{
-				Config: Config{
+				DefaultConfig: Config{
 					BotAPIKey: "something",
 					Domain:    "something",
 					ChannelID: "something",
 				},
 			},
-			expected: false,
+			ExpectedError: ErrBotEmailNotSet,
 		},
 		{
-			name: "Valid provider",
+			Name: "Valid provider",
-			alertProvider: AlertProvider{
+			AlertProvider: AlertProvider{
-				Config: Config{
+				DefaultConfig: Config{
 					BotEmail:  "something",
 					BotAPIKey: "something",
 					Domain:    "something",
 					ChannelID: "something",
 				},
 			},
-			expected: true,
+			ExpectedError: nil,
 		},
 	}
-	for _, tc := range testCase {
+	for _, scenario := range scenarios {
-		t.Run(tc.name, func(t *testing.T) {
+		t.Run(scenario.Name, func(t *testing.T) {
-			if tc.alertProvider.IsValid() != tc.expected {
+			if err := scenario.AlertProvider.Validate(); !errors.Is(err, scenario.ExpectedError) {
-				t.Errorf("IsValid assertion failed (expected %v, got %v)", tc.expected, !tc.expected)
+				t.Errorf("ExpectedError error %v, got %v", scenario.ExpectedError, err)
 			}
 		})
 	}
 }
 
-func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
-	validConfig := Config{
-		BotEmail:  "something",
-		BotAPIKey: "something",
-		Domain:    "something",
-		ChannelID: "something",
-	}
-
-	testCase := []struct {
-		name          string
-		alertProvider AlertProvider
-		expected      bool
-	}{
-		{
-			name: "Empty group",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Config: validConfig,
-						Group:  "",
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Empty override config",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group: "something",
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Empty channel id",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group: "something",
-						Config: Config{
-							BotEmail:  "something",
-							BotAPIKey: "something",
-							Domain:    "something",
-						},
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Empty domain",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group: "something",
-						Config: Config{
-							BotEmail:  "something",
-							BotAPIKey: "something",
-							ChannelID: "something",
-						},
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Empty bot api key",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group: "something",
-						Config: Config{
-							BotEmail:  "something",
-							Domain:    "something",
-							ChannelID: "something",
-						},
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Empty bot email",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group: "something",
-						Config: Config{
-							BotAPIKey: "something",
-							Domain:    "something",
-							ChannelID: "something",
-						},
-					},
-				},
-			},
-			expected: false,
-		},
-		{
-			name: "Valid provider",
-			alertProvider: AlertProvider{
-				Config: validConfig,
-				Overrides: []Override{
-					{
-						Group:  "something",
-						Config: validConfig,
-					},
-				},
-			},
-			expected: true,
-		},
-	}
-	for _, tc := range testCase {
-		t.Run(tc.name, func(t *testing.T) {
-			if tc.alertProvider.IsValid() != tc.expected {
-				t.Errorf("IsValid assertion failed (expected %v, got %v)", tc.expected, !tc.expected)
-			}
-		})
-	}
-}
-
-func TestAlertProvider_GetChannelIdForGroup(t *testing.T) {
-	provider := AlertProvider{
-		Config: Config{
-			ChannelID: "default",
-		},
-		Overrides: []Override{
-			{
-				Group:  "group1",
-				Config: Config{ChannelID: "group1"},
-			},
-			{
-				Group:  "group2",
-				Config: Config{ChannelID: "group2"},
-			},
-		},
-	}
-	if provider.getChannelIdForGroup("") != "default" {
-		t.Error("Expected default channel ID")
-	}
-	if provider.getChannelIdForGroup("group2") != "group2" {
-		t.Error("Expected group2 channel ID")
-	}
-}
-
-func TestAlertProvider_BuildRequestBody(t *testing.T) {
 	basicConfig := Config{
 		BotEmail:  "bot-email",
 		BotAPIKey: "bot-api-key",
@@ -266,13 +114,13 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 		{
 			name: "Resolved alert with no conditions",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:         basicAlert,
 			resolved:      true,
 			hasConditions: false,
 			expectedBody: url.Values{
-				"content": {`An alert for **endpoint-name** has been resolved after passing successfully 2 time(s) in a row
+				"content": {`An alert for **endpoint-Name** has been resolved after passing successfully 2 time(s) in a row
 > Description
 `},
 				"to":    {"channel-id"},
@@ -283,13 +131,13 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 		{
 			name: "Resolved alert with conditions",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:         basicAlert,
 			resolved:      true,
 			hasConditions: true,
 			expectedBody: url.Values{
-				"content": {`An alert for **endpoint-name** has been resolved after passing successfully 2 time(s) in a row
+				"content": {`An alert for **endpoint-Name** has been resolved after passing successfully 2 time(s) in a row
 > Description
 
 :check: - ` + "`[CONNECTED] == true`" + `
@@ -303,13 +151,13 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 		{
 			name: "Failed alert with no conditions",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:         basicAlert,
 			resolved:      false,
 			hasConditions: false,
 			expectedBody: url.Values{
-				"content": {`An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row
+				"content": {`An alert for **endpoint-Name** has been triggered due to having failed 3 time(s) in a row
 > Description
 `},
 				"to":    {"channel-id"},
@@ -320,13 +168,13 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 		{
 			name: "Failed alert with conditions",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:         basicAlert,
 			resolved:      false,
 			hasConditions: true,
 			expectedBody: url.Values{
-				"content": {`An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row
+				"content": {`An alert for **endpoint-Name** has been triggered due to having failed 3 time(s) in a row
 > Description
 
 :cross_mark: - ` + "`[CONNECTED] == true`" + `
@@ -349,7 +197,8 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 				}
 			}
 			body := tc.provider.buildRequestBody(
-				&endpoint.Endpoint{Name: "endpoint-name"},
+				&tc.provider.DefaultConfig,
+				&endpoint.Endpoint{Name: "endpoint-Name"},
 				&tc.alert,
 				&endpoint.Result{
 					ConditionResults: conditionResults,
@@ -369,10 +218,10 @@ func TestAlertProvider_BuildRequestBody(t *testing.T) {
 
 func TestAlertProvider_GetDefaultAlert(t *testing.T) {
 	if (&AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
-		t.Error("expected default alert to be not nil")
+		t.Error("ExpectedError default alert to be not nil")
 	}
 	if (&AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
-		t.Error("expected default alert to be nil")
+		t.Error("ExpectedError default alert to be nil")
 	}
 }
 
@@ -380,16 +229,16 @@ func TestAlertProvider_Send(t *testing.T) {
 	defer client.InjectHTTPClient(nil)
 	validateRequest := func(req *http.Request) {
 		if req.URL.String() != "https://custom-domain/api/v1/messages" {
-			t.Errorf("expected url https://custom-domain.zulipchat.com/api/v1/messages, got %s", req.URL.String())
+			t.Errorf("ExpectedError url https://custom-domain.zulipchat.com/api/v1/messages, got %s", req.URL.String())
 		}
 		if req.Method != http.MethodPost {
-			t.Errorf("expected POST request, got %s", req.Method)
+			t.Errorf("ExpectedError POST request, got %s", req.Method)
 		}
 		if req.Header.Get("Content-Type") != "application/x-www-form-urlencoded" {
-			t.Errorf("expected Content-Type header to be application/x-www-form-urlencoded, got %s", req.Header.Get("Content-Type"))
+			t.Errorf("ExpectedError Content-Type header to be application/x-www-form-urlencoded, got %s", req.Header.Get("Content-Type"))
 		}
 		if req.Header.Get("User-Agent") != "Gatus" {
-			t.Errorf("expected User-Agent header to be Gatus, got %s", req.Header.Get("User-Agent"))
+			t.Errorf("ExpectedError User-Agent header to be Gatus, got %s", req.Header.Get("User-Agent"))
 		}
 	}
 	basicConfig := Config{
@@ -413,7 +262,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		{
 			name: "resolved",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:    basicAlert,
 			resolved: true,
@@ -426,7 +275,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		{
 			name: "resolved error",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:    basicAlert,
 			resolved: true,
@@ -439,7 +288,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		{
 			name: "triggered",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:    basicAlert,
 			resolved: false,
@@ -452,7 +301,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		{
 			name: "triggered error",
 			provider: AlertProvider{
-				Config: basicConfig,
+				DefaultConfig: basicConfig,
 			},
 			alert:    basicAlert,
 			resolved: false,
@@ -467,7 +316,7 @@ func TestAlertProvider_Send(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			client.InjectHTTPClient(&http.Client{Transport: tc.mockRoundTripper})
 			err := tc.provider.Send(
-				&endpoint.Endpoint{Name: "endpoint-name"},
+				&endpoint.Endpoint{Name: "endpoint-Name"},
 				&tc.alert,
 				&endpoint.Result{
 					ConditionResults: []*endpoint.ConditionResult{
@@ -478,10 +327,155 @@ func TestAlertProvider_Send(t *testing.T) {
 				tc.resolved,
 			)
 			if tc.expectedError && err == nil {
-				t.Error("expected error, got none")
+				t.Error("ExpectedError error, got none")
 			}
 			if !tc.expectedError && err != nil {
-				t.Errorf("expected no error, got: %v", err)
+				t.Errorf("ExpectedError no error, got: %v", err)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetConfig(t *testing.T) {
+	scenarios := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		InputAlert     alert.Alert
+		ExpectedOutput Config
+	}{
+		{
+			Name: "provider-no-overrides",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					BotEmail:  "default-bot-email",
+					BotAPIKey: "default-bot-api-key",
+					Domain:    "default-domain",
+					ChannelID: "default-channel-id",
+				},
+				Overrides: nil,
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
+				BotEmail:  "default-bot-email",
+				BotAPIKey: "default-bot-api-key",
+				Domain:    "default-domain",
+				ChannelID: "default-channel-id",
+			},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					BotEmail:  "default-bot-email",
+					BotAPIKey: "default-bot-api-key",
+					Domain:    "default-domain",
+					ChannelID: "default-channel-id",
+				},
+				Overrides: []Override{
+					{
+						Group:  "group",
+						Config: Config{ChannelID: "group-channel-id"},
+					},
+				},
+			},
+			InputGroup: "",
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
+				BotEmail:  "default-bot-email",
+				BotAPIKey: "default-bot-api-key",
+				Domain:    "default-domain",
+				ChannelID: "default-channel-id",
+			},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					BotEmail:  "default-bot-email",
+					BotAPIKey: "default-bot-api-key",
+					Domain:    "default-domain",
+					ChannelID: "default-channel-id",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						Config: Config{
+							BotEmail:  "group-bot-email",
+							BotAPIKey: "group-bot-api-key",
+							Domain:    "group-domain",
+							ChannelID: "group-channel-id",
+						},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{},
+			ExpectedOutput: Config{
+				BotEmail:  "group-bot-email",
+				BotAPIKey: "group-bot-api-key",
+				Domain:    "group-domain",
+				ChannelID: "group-channel-id",
+			},
+		},
+		{
+			Name: "provider-with-group-override-and-alert-override--alert-override-should-take-precedence",
+			Provider: AlertProvider{
+				DefaultConfig: Config{
+					BotEmail:  "default-bot-email",
+					BotAPIKey: "default-bot-api-key",
+					Domain:    "default-domain",
+					ChannelID: "default-channel-id",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						Config: Config{
+							BotEmail:  "group-bot-email",
+							BotAPIKey: "group-bot-api-key",
+							Domain:    "group-domain",
+							ChannelID: "group-channel-id",
+						},
+					},
+				},
+			},
+			InputGroup: "group",
+			InputAlert: alert.Alert{ProviderOverride: map[string]any{
+				"bot-email":   "alert-bot-email",
+				"bot-api-key": "alert-bot-api-key",
+				"domain":      "alert-domain",
+				"channel-id":  "alert-channel-id",
+			}},
+			ExpectedOutput: Config{
+				BotEmail:  "alert-bot-email",
+				BotAPIKey: "alert-bot-api-key",
+				Domain:    "alert-domain",
+				ChannelID: "alert-channel-id",
+			},
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			got, err := scenario.Provider.GetConfig(scenario.InputGroup, &scenario.InputAlert)
+			if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+			if got.BotEmail != scenario.ExpectedOutput.BotEmail {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.BotEmail, got.BotEmail)
+			}
+			if got.BotAPIKey != scenario.ExpectedOutput.BotAPIKey {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.BotAPIKey, got.BotAPIKey)
+			}
+			if got.Domain != scenario.ExpectedOutput.Domain {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.Domain, got.Domain)
+			}
+			if got.ChannelID != scenario.ExpectedOutput.ChannelID {
+				t.Errorf("expected %s, got %s", scenario.ExpectedOutput.ChannelID, got.ChannelID)
+			}
+			// Test ValidateOverrides as well, since it really just calls GetConfig
+			if err = scenario.Provider.ValidateOverrides(scenario.InputGroup, &scenario.InputAlert); err != nil {
+				t.Errorf("unexpected error: %s", err)
 			}
 		})
 	}

config/config.go

@@ -22,6 +22,7 @@ import (
 	"github.com/TwiN/gatus/v5/security"
 	"github.com/TwiN/gatus/v5/storage"
 	"github.com/TwiN/logr"
+	"github.com/gofiber/fiber/v2/log"
 	"gopkg.in/yaml.v3"
 )
 
@@ -421,14 +422,20 @@ func validateAlertingConfig(alertingConfig *alerting.Config, endpoints []*endpoi
 	for _, alertType := range alertTypes {
 		alertProvider := alertingConfig.GetAlertingProviderByAlertType(alertType)
 		if alertProvider != nil {
-			if alertProvider.IsValid() {
+			if err := alertProvider.Validate(); err == nil {
 				// Parse alerts with the provider's default alert
 				if alertProvider.GetDefaultAlert() != nil {
 					for _, ep := range endpoints {
 						for alertIndex, endpointAlert := range ep.Alerts {
 							if alertType == endpointAlert.Type {
 								logr.Debugf("[config.validateAlertingConfig] Parsing alert %d with default alert for provider=%s in endpoint with key=%s", alertIndex, alertType, ep.Key())
-								provider.ParseWithDefaultAlert(alertProvider.GetDefaultAlert(), endpointAlert)
+								provider.MergeProviderDefaultAlertIntoEndpointAlert(alertProvider.GetDefaultAlert(), endpointAlert)
+								// Validate the endpoint alert's overrides, if applicable
+								if len(endpointAlert.ProviderOverride) > 0 {
+									if err = alertProvider.ValidateOverrides(ep.Group, endpointAlert); err != nil {
+										log.Warnf("[config.validateAlertingConfig] endpoint with key=%s has invalid overrides for provider=%s: %s", ep.Key(), alertType, err.Error())
+									}
+								}
 							}
 						}
 					}
@@ -436,14 +443,20 @@ func validateAlertingConfig(alertingConfig *alerting.Config, endpoints []*endpoi
 						for alertIndex, endpointAlert := range ee.Alerts {
 							if alertType == endpointAlert.Type {
 								logr.Debugf("[config.validateAlertingConfig] Parsing alert %d with default alert for provider=%s in endpoint with key=%s", alertIndex, alertType, ee.Key())
-								provider.ParseWithDefaultAlert(alertProvider.GetDefaultAlert(), endpointAlert)
+								provider.MergeProviderDefaultAlertIntoEndpointAlert(alertProvider.GetDefaultAlert(), endpointAlert)
+								// Validate the endpoint alert's overrides, if applicable
+								if len(endpointAlert.ProviderOverride) > 0 {
+									if err = alertProvider.ValidateOverrides(ee.Group, endpointAlert); err != nil {
+										log.Warnf("[config.validateAlertingConfig] endpoint with key=%s has invalid overrides for provider=%s: %s", ee.Key(), alertType, err.Error())
+									}
+								}
 							}
 						}
 					}
 				}
 				validProviders = append(validProviders, alertType)
 			} else {
-				logr.Warnf("[config.validateAlertingConfig] Ignoring provider=%s because configuration is invalid", alertType)
+				logr.Warnf("[config.validateAlertingConfig] Ignoring provider=%s due to error=%s", alertType, err.Error())
 				invalidProviders = append(invalidProviders, alertType)
 				alertingConfig.SetAlertingProviderToNil(alertProvider)
 			}

config/config_test.go

@@ -11,10 +11,13 @@ import (
 	"github.com/TwiN/gatus/v5/alerting"
 	"github.com/TwiN/gatus/v5/alerting/alert"
 	"github.com/TwiN/gatus/v5/alerting/provider"
+	"github.com/TwiN/gatus/v5/alerting/provider/awsses"
 	"github.com/TwiN/gatus/v5/alerting/provider/custom"
 	"github.com/TwiN/gatus/v5/alerting/provider/discord"
 	"github.com/TwiN/gatus/v5/alerting/provider/email"
+	"github.com/TwiN/gatus/v5/alerting/provider/gitea"
 	"github.com/TwiN/gatus/v5/alerting/provider/github"
+	"github.com/TwiN/gatus/v5/alerting/provider/gitlab"
 	"github.com/TwiN/gatus/v5/alerting/provider/googlechat"
 	"github.com/TwiN/gatus/v5/alerting/provider/gotify"
 	"github.com/TwiN/gatus/v5/alerting/provider/jetbrainsspace"
@@ -30,6 +33,7 @@ import (
 	"github.com/TwiN/gatus/v5/alerting/provider/teamsworkflows"
 	"github.com/TwiN/gatus/v5/alerting/provider/telegram"
 	"github.com/TwiN/gatus/v5/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v5/alerting/provider/zulip"
 	"github.com/TwiN/gatus/v5/client"
 	"github.com/TwiN/gatus/v5/config/endpoint"
 	"github.com/TwiN/gatus/v5/config/web"
@@ -198,8 +202,8 @@ endpoints:
 			expectedConfig: &Config{
 				Metrics: true,
 				Alerting: &alerting.Config{
-					Discord: &discord.AlertProvider{WebhookURL: "https://discord.com/api/webhooks/xxx/yyy"},
+					Discord: &discord.AlertProvider{DefaultConfig: discord.Config{WebhookURL: "https://discord.com/api/webhooks/xxx/yyy"}},
-					Slack:   &slack.AlertProvider{WebhookURL: "https://hooks.slack.com/services/xxx/yyy/zzz", DefaultAlert: &alert.Alert{Enabled: &yes}},
+					Slack:   &slack.AlertProvider{DefaultConfig: slack.Config{WebhookURL: "https://hooks.slack.com/services/xxx/yyy/zzz"}, DefaultAlert: &alert.Alert{Enabled: &yes}},
 				},
 				ExternalEndpoints: []*endpoint.ExternalEndpoint{
 					{
@@ -481,7 +485,7 @@ endpoints:
 		t.Error("expected no error, got", err.Error())
 	}
 	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
+		t.Fatal("DefaultConfig shouldn't have been nil")
 	}
 	if config.Metrics {
 		t.Error("Metrics should've been false by default")
@@ -786,7 +790,7 @@ endpoints:
 	if config.Alerting == nil {
 		t.Fatal("config.Alerting shouldn't have been nil")
 	}
-	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
+	if config.Alerting.Slack == nil || config.Alerting.Slack.Validate() != nil {
 		t.Fatal("Slack alerting config should've been valid")
 	}
 	// Endpoints
@@ -1037,63 +1041,64 @@ endpoints:
 	if config.Alerting == nil {
 		t.Fatal("config.Alerting shouldn't have been nil")
 	}
-	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
+
+	if config.Alerting.Slack == nil || config.Alerting.Slack.Validate() != nil {
 		t.Fatal("Slack alerting config should've been valid")
 	}
 	if config.Alerting.Slack.GetDefaultAlert() == nil {
 		t.Fatal("Slack.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Slack.WebhookURL != "http://example.com" {
+	if config.Alerting.Slack.DefaultConfig.WebhookURL != "http://example.com" {
-		t.Errorf("Slack webhook should've been %s, but was %s", "http://example.com", config.Alerting.Slack.WebhookURL)
+		t.Errorf("Slack webhook should've been %s, but was %s", "http://example.com", config.Alerting.Slack.DefaultConfig.WebhookURL)
 	}
 
-	if config.Alerting.PagerDuty == nil || !config.Alerting.PagerDuty.IsValid() {
+	if config.Alerting.PagerDuty == nil || config.Alerting.PagerDuty.Validate() != nil {
 		t.Fatal("PagerDuty alerting config should've been valid")
 	}
 	if config.Alerting.PagerDuty.GetDefaultAlert() == nil {
 		t.Fatal("PagerDuty.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.PagerDuty.IntegrationKey != "00000000000000000000000000000000" {
+	if config.Alerting.PagerDuty.DefaultConfig.IntegrationKey != "00000000000000000000000000000000" {
-		t.Errorf("PagerDuty integration key should've been %s, but was %s", "00000000000000000000000000000000", config.Alerting.PagerDuty.IntegrationKey)
+		t.Errorf("PagerDuty integration key should've been %s, but was %s", "00000000000000000000000000000000", config.Alerting.PagerDuty.DefaultConfig.IntegrationKey)
 	}
 
-	if config.Alerting.Pushover == nil || !config.Alerting.Pushover.IsValid() {
+	if config.Alerting.Pushover == nil || config.Alerting.Pushover.Validate() != nil {
 		t.Fatal("Pushover alerting config should've been valid")
 	}
 	if config.Alerting.Pushover.GetDefaultAlert() == nil {
 		t.Fatal("Pushover.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Pushover.ApplicationToken != "000000000000000000000000000000" {
+	if config.Alerting.Pushover.DefaultConfig.ApplicationToken != "000000000000000000000000000000" {
-		t.Errorf("Pushover application token should've been %s, but was %s", "000000000000000000000000000000", config.Alerting.Pushover.ApplicationToken)
+		t.Errorf("Pushover application token should've been %s, but was %s", "000000000000000000000000000000", config.Alerting.Pushover.DefaultConfig.ApplicationToken)
 	}
-	if config.Alerting.Pushover.UserKey != "000000000000000000000000000000" {
+	if config.Alerting.Pushover.DefaultConfig.UserKey != "000000000000000000000000000000" {
-		t.Errorf("Pushover user key should've been %s, but was %s", "000000000000000000000000000000", config.Alerting.Pushover.UserKey)
+		t.Errorf("Pushover user key should've been %s, but was %s", "000000000000000000000000000000", config.Alerting.Pushover.DefaultConfig.UserKey)
 	}
 
-	if config.Alerting.Mattermost == nil || !config.Alerting.Mattermost.IsValid() {
+	if config.Alerting.Mattermost == nil || config.Alerting.Mattermost.Validate() != nil {
 		t.Fatal("Mattermost alerting config should've been valid")
 	}
 	if config.Alerting.Mattermost.GetDefaultAlert() == nil {
 		t.Fatal("Mattermost.GetDefaultAlert() shouldn't have returned nil")
 	}
 
-	if config.Alerting.Messagebird == nil || !config.Alerting.Messagebird.IsValid() {
+	if config.Alerting.Messagebird == nil || config.Alerting.Messagebird.Validate() != nil {
 		t.Fatal("Messagebird alerting config should've been valid")
 	}
 	if config.Alerting.Messagebird.GetDefaultAlert() == nil {
 		t.Fatal("Messagebird.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Messagebird.AccessKey != "1" {
+	if config.Alerting.Messagebird.DefaultConfig.AccessKey != "1" {
-		t.Errorf("Messagebird access key should've been %s, but was %s", "1", config.Alerting.Messagebird.AccessKey)
+		t.Errorf("Messagebird access key should've been %s, but was %s", "1", config.Alerting.Messagebird.DefaultConfig.AccessKey)
 	}
-	if config.Alerting.Messagebird.Originator != "31619191918" {
+	if config.Alerting.Messagebird.DefaultConfig.Originator != "31619191918" {
-		t.Errorf("Messagebird originator field should've been %s, but was %s", "31619191918", config.Alerting.Messagebird.Originator)
+		t.Errorf("Messagebird originator field should've been %s, but was %s", "31619191918", config.Alerting.Messagebird.DefaultConfig.Originator)
 	}
-	if config.Alerting.Messagebird.Recipients != "31619191919" {
+	if config.Alerting.Messagebird.DefaultConfig.Recipients != "31619191919" {
-		t.Errorf("Messagebird to recipients should've been %s, but was %s", "31619191919", config.Alerting.Messagebird.Recipients)
+		t.Errorf("Messagebird to recipients should've been %s, but was %s", "31619191919", config.Alerting.Messagebird.DefaultConfig.Recipients)
 	}
 
-	if config.Alerting.Discord == nil || !config.Alerting.Discord.IsValid() {
+	if config.Alerting.Discord == nil || config.Alerting.Discord.Validate() != nil {
 		t.Fatal("Discord alerting config should've been valid")
 	}
 	if config.Alerting.Discord.GetDefaultAlert() == nil {
@@ -1105,98 +1110,98 @@ endpoints:
 	if config.Alerting.Discord.GetDefaultAlert().SuccessThreshold != 15 {
 		t.Errorf("Discord default alert success threshold should've been %d, but was %d", 15, config.Alerting.Discord.GetDefaultAlert().SuccessThreshold)
 	}
-	if config.Alerting.Discord.WebhookURL != "http://example.org" {
+	if config.Alerting.Discord.DefaultConfig.WebhookURL != "http://example.org" {
-		t.Errorf("Discord webhook should've been %s, but was %s", "http://example.org", config.Alerting.Discord.WebhookURL)
+		t.Errorf("Discord webhook should've been %s, but was %s", "http://example.org", config.Alerting.Discord.DefaultConfig.WebhookURL)
 	}
 	if config.Alerting.GetAlertingProviderByAlertType(alert.TypeDiscord) != config.Alerting.Discord {
 		t.Error("expected discord configuration")
 	}
 
-	if config.Alerting.Telegram == nil || !config.Alerting.Telegram.IsValid() {
+	if config.Alerting.Telegram == nil || config.Alerting.Telegram.Validate() != nil {
 		t.Fatal("Telegram alerting config should've been valid")
 	}
 	if config.Alerting.Telegram.GetDefaultAlert() == nil {
 		t.Fatal("Telegram.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Telegram.Token != "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11" {
+	if config.Alerting.Telegram.DefaultConfig.Token != "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11" {
-		t.Errorf("Telegram token should've been %s, but was %s", "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", config.Alerting.Telegram.Token)
+		t.Errorf("Telegram token should've been %s, but was %s", "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", config.Alerting.Telegram.DefaultConfig.Token)
 	}
-	if config.Alerting.Telegram.ID != "0123456789" {
+	if config.Alerting.Telegram.DefaultConfig.ID != "0123456789" {
-		t.Errorf("Telegram ID should've been %s, but was %s", "012345689", config.Alerting.Telegram.ID)
+		t.Errorf("Telegram ID should've been %s, but was %s", "012345689", config.Alerting.Telegram.DefaultConfig.ID)
 	}
 
-	if config.Alerting.Twilio == nil || !config.Alerting.Twilio.IsValid() {
+	if config.Alerting.Twilio == nil || config.Alerting.Twilio.Validate() != nil {
 		t.Fatal("Twilio alerting config should've been valid")
 	}
 	if config.Alerting.Twilio.GetDefaultAlert() == nil {
 		t.Fatal("Twilio.GetDefaultAlert() shouldn't have returned nil")
 	}
 
-	if config.Alerting.Teams == nil || !config.Alerting.Teams.IsValid() {
+	if config.Alerting.Teams == nil || config.Alerting.Teams.Validate() != nil {
 		t.Fatal("Teams alerting config should've been valid")
 	}
 	if config.Alerting.Teams.GetDefaultAlert() == nil {
 		t.Fatal("Teams.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.JetBrainsSpace == nil || !config.Alerting.JetBrainsSpace.IsValid() {
+
+	if config.Alerting.JetBrainsSpace == nil || config.Alerting.JetBrainsSpace.Validate() != nil {
 		t.Fatal("JetBrainsSpace alerting config should've been valid")
 	}
-
 	if config.Alerting.JetBrainsSpace.GetDefaultAlert() == nil {
 		t.Fatal("JetBrainsSpace.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.JetBrainsSpace.Project != "foo" {
+	if config.Alerting.JetBrainsSpace.DefaultConfig.Project != "foo" {
-		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "foo", config.Alerting.JetBrainsSpace.Project)
+		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "foo", config.Alerting.JetBrainsSpace.DefaultConfig.Project)
 	}
-	if config.Alerting.JetBrainsSpace.ChannelID != "bar" {
+	if config.Alerting.JetBrainsSpace.DefaultConfig.ChannelID != "bar" {
-		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "bar", config.Alerting.JetBrainsSpace.ChannelID)
+		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "bar", config.Alerting.JetBrainsSpace.DefaultConfig.ChannelID)
 	}
-	if config.Alerting.JetBrainsSpace.Token != "baz" {
+	if config.Alerting.JetBrainsSpace.DefaultConfig.Token != "baz" {
-		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "baz", config.Alerting.JetBrainsSpace.Token)
+		t.Errorf("JetBrainsSpace webhook should've been %s, but was %s", "baz", config.Alerting.JetBrainsSpace.DefaultConfig.Token)
 	}
 
-	if config.Alerting.Email == nil || !config.Alerting.Email.IsValid() {
+	if config.Alerting.Email == nil || config.Alerting.Email.Validate() != nil {
 		t.Fatal("Email alerting config should've been valid")
 	}
 	if config.Alerting.Email.GetDefaultAlert() == nil {
 		t.Fatal("Email.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Email.From != "from@example.com" {
+	if config.Alerting.Email.DefaultConfig.From != "from@example.com" {
-		t.Errorf("Email from should've been %s, but was %s", "from@example.com", config.Alerting.Email.From)
+		t.Errorf("Email from should've been %s, but was %s", "from@example.com", config.Alerting.Email.DefaultConfig.From)
 	}
-	if config.Alerting.Email.Username != "from@example.com" {
+	if config.Alerting.Email.DefaultConfig.Username != "from@example.com" {
-		t.Errorf("Email username should've been %s, but was %s", "from@example.com", config.Alerting.Email.Username)
+		t.Errorf("Email username should've been %s, but was %s", "from@example.com", config.Alerting.Email.DefaultConfig.Username)
 	}
-	if config.Alerting.Email.Password != "hunter2" {
+	if config.Alerting.Email.DefaultConfig.Password != "hunter2" {
-		t.Errorf("Email password should've been %s, but was %s", "hunter2", config.Alerting.Email.Password)
+		t.Errorf("Email password should've been %s, but was %s", "hunter2", config.Alerting.Email.DefaultConfig.Password)
 	}
-	if config.Alerting.Email.Host != "mail.example.com" {
+	if config.Alerting.Email.DefaultConfig.Host != "mail.example.com" {
-		t.Errorf("Email host should've been %s, but was %s", "mail.example.com", config.Alerting.Email.Host)
+		t.Errorf("Email host should've been %s, but was %s", "mail.example.com", config.Alerting.Email.DefaultConfig.Host)
 	}
-	if config.Alerting.Email.Port != 587 {
+	if config.Alerting.Email.DefaultConfig.Port != 587 {
-		t.Errorf("Email port should've been %d, but was %d", 587, config.Alerting.Email.Port)
+		t.Errorf("Email port should've been %d, but was %d", 587, config.Alerting.Email.DefaultConfig.Port)
 	}
-	if config.Alerting.Email.To != "recipient1@example.com,recipient2@example.com" {
+	if config.Alerting.Email.DefaultConfig.To != "recipient1@example.com,recipient2@example.com" {
-		t.Errorf("Email to should've been %s, but was %s", "recipient1@example.com,recipient2@example.com", config.Alerting.Email.To)
+		t.Errorf("Email to should've been %s, but was %s", "recipient1@example.com,recipient2@example.com", config.Alerting.Email.DefaultConfig.To)
 	}
-	if config.Alerting.Email.ClientConfig == nil {
+	if config.Alerting.Email.DefaultConfig.ClientConfig == nil {
 		t.Fatal("Email client config should've been set")
 	}
-	if config.Alerting.Email.ClientConfig.Insecure {
+	if config.Alerting.Email.DefaultConfig.ClientConfig.Insecure {
 		t.Error("Email client config should've been secure")
 	}
 
-	if config.Alerting.Gotify == nil || !config.Alerting.Gotify.IsValid() {
+	if config.Alerting.Gotify == nil || config.Alerting.Gotify.Validate() != nil {
 		t.Fatal("Gotify alerting config should've been valid")
 	}
 	if config.Alerting.Gotify.GetDefaultAlert() == nil {
 		t.Fatal("Gotify.GetDefaultAlert() shouldn't have returned nil")
 	}
-	if config.Alerting.Gotify.ServerURL != "https://gotify.example" {
+	if config.Alerting.Gotify.DefaultConfig.ServerURL != "https://gotify.example" {
-		t.Errorf("Gotify server URL should've been %s, but was %s", "https://gotify.example", config.Alerting.Gotify.ServerURL)
+		t.Errorf("Gotify server URL should've been %s, but was %s", "https://gotify.example", config.Alerting.Gotify.DefaultConfig.ServerURL)
 	}
-	if config.Alerting.Gotify.Token != "**************" {
+	if config.Alerting.Gotify.DefaultConfig.Token != "**************" {
-		t.Errorf("Gotify token should've been %s, but was %s", "**************", config.Alerting.Gotify.Token)
+		t.Errorf("Gotify token should've been %s, but was %s", "**************", config.Alerting.Gotify.DefaultConfig.Token)
 	}
 
 	// External endpoints
@@ -1405,6 +1410,8 @@ endpoints:
      - type: slack
        enabled: false
        failure-threshold: 30
+       provider-override:
+         webhook-url: https://example.com
    conditions:
      - "[STATUS] == 200"
 `))
@@ -1418,7 +1425,7 @@ endpoints:
 	if config.Alerting == nil {
 		t.Fatal("config.Alerting shouldn't have been nil")
 	}
-	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
+	if config.Alerting.Slack == nil || config.Alerting.Slack.Validate() != nil {
 		t.Fatal("Slack alerting config should've been valid")
 	}
 	// Endpoints
@@ -1546,17 +1553,18 @@ endpoints:
 	if config.Alerting.Custom == nil {
 		t.Fatal("Custom alerting config shouldn't have been nil")
 	}
-	if !config.Alerting.Custom.IsValid() {
+	if err = config.Alerting.Custom.Validate(); err != nil {
 		t.Fatal("Custom alerting config should've been valid")
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(true) != "RESOLVED" {
+	cfg, _ := config.Alerting.Custom.GetConfig("", &alert.Alert{ProviderOverride: map[string]any{"client": map[string]any{"insecure": true}}})
-		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for RESOLVED should've been 'RESOLVED', got", config.Alerting.Custom.GetAlertStatePlaceholderValue(true))
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, true) != "RESOLVED" {
+		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for RESOLVED should've been 'RESOLVED', got", config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, true))
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(false) != "TRIGGERED" {
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, false) != "TRIGGERED" {
-		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for TRIGGERED should've been 'TRIGGERED', got", config.Alerting.Custom.GetAlertStatePlaceholderValue(false))
+		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for TRIGGERED should've been 'TRIGGERED', got", config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, false))
 	}
-	if config.Alerting.Custom.ClientConfig.Insecure {
+	if !cfg.ClientConfig.Insecure {
-		t.Errorf("ClientConfig.Insecure should have been %v, got %v", false, config.Alerting.Custom.ClientConfig.Insecure)
+		t.Errorf("ClientConfig.Insecure should have been %v, got %v", true, cfg.ClientConfig.Insecure)
 	}
 }
 
@@ -1583,7 +1591,7 @@ endpoints:
 		t.Error("expected no error, got", err.Error())
 	}
 	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
+		t.Fatal("DefaultConfig shouldn't have been nil")
 	}
 	if config.Alerting == nil {
 		t.Fatal("config.Alerting shouldn't have been nil")
@@ -1591,13 +1599,14 @@ endpoints:
 	if config.Alerting.Custom == nil {
 		t.Fatal("Custom alerting config shouldn't have been nil")
 	}
-	if !config.Alerting.Custom.IsValid() {
+	if err = config.Alerting.Custom.Validate(); err != nil {
 		t.Fatal("Custom alerting config should've been valid")
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(true) != "operational" {
+	cfg, _ := config.Alerting.Custom.GetConfig("", &alert.Alert{})
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, true) != "operational" {
 		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for RESOLVED should've been 'operational'")
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(false) != "partial_outage" {
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, false) != "partial_outage" {
 		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for TRIGGERED should've been 'partial_outage'")
 	}
 }
@@ -1623,7 +1632,7 @@ endpoints:
 		t.Error("expected no error, got", err.Error())
 	}
 	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
+		t.Fatal("DefaultConfig shouldn't have been nil")
 	}
 	if config.Alerting == nil {
 		t.Fatal("config.Alerting shouldn't have been nil")
@@ -1631,13 +1640,14 @@ endpoints:
 	if config.Alerting.Custom == nil {
 		t.Fatal("Custom alerting config shouldn't have been nil")
 	}
-	if !config.Alerting.Custom.IsValid() {
+	if err := config.Alerting.Custom.Validate(); err != nil {
 		t.Fatal("Custom alerting config should've been valid")
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(true) != "RESOLVED" {
+	cfg, _ := config.Alerting.Custom.GetConfig("", &alert.Alert{})
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, true) != "RESOLVED" {
 		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for RESOLVED should've been 'RESOLVED'")
 	}
-	if config.Alerting.Custom.GetAlertStatePlaceholderValue(false) != "partial_outage" {
+	if config.Alerting.Custom.GetAlertStatePlaceholderValue(cfg, false) != "partial_outage" {
 		t.Fatal("ALERT_TRIGGERED_OR_RESOLVED placeholder value for TRIGGERED should've been 'partial_outage'")
 	}
 }
@@ -1813,7 +1823,7 @@ endpoints:
 		t.Error("expected no error, got", err.Error())
 	}
 	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
+		t.Fatal("DefaultConfig shouldn't have been nil")
 	}
 	if config.Security == nil {
 		t.Fatal("config.Security shouldn't have been nil")
@@ -1846,7 +1856,7 @@ endpoints:
 		t.Error("expected no error, got", err.Error())
 	}
 	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
+		t.Fatal("DefaultConfig shouldn't have been nil")
 	}
 	if config.Endpoints[0].URL != "https://twin.sh/health" {
 		t.Errorf("URL should have been %s", "https://twin.sh/health")
@@ -1868,10 +1878,13 @@ func TestParseAndValidateConfigBytesWithNoEndpoints(t *testing.T) {
 
 func TestGetAlertingProviderByAlertType(t *testing.T) {
 	alertingConfig := &alerting.Config{
+		AWSSimpleEmailService: &awsses.AlertProvider{},
 		Custom:                &custom.AlertProvider{},
 		Discord:               &discord.AlertProvider{},
 		Email:                 &email.AlertProvider{},
+		Gitea:                 &gitea.AlertProvider{},
 		GitHub:                &github.AlertProvider{},
+		GitLab:                &gitlab.AlertProvider{},
 		GoogleChat:            &googlechat.AlertProvider{},
 		Gotify:                &gotify.AlertProvider{},
 		JetBrainsSpace:        &jetbrainsspace.AlertProvider{},
@@ -1884,18 +1897,22 @@ func TestGetAlertingProviderByAlertType(t *testing.T) {
 		Pushover:              &pushover.AlertProvider{},
 		Slack:                 &slack.AlertProvider{},
 		Telegram:              &telegram.AlertProvider{},
-		Twilio:         &twilio.AlertProvider{},
 		Teams:                 &teams.AlertProvider{},
 		TeamsWorkflows:        &teamsworkflows.AlertProvider{},
+		Twilio:                &twilio.AlertProvider{},
+		Zulip:                 &zulip.AlertProvider{},
 	}
 	scenarios := []struct {
 		alertType alert.Type
 		expected  provider.AlertProvider
 	}{
+		{alertType: alert.TypeAWSSES, expected: alertingConfig.AWSSimpleEmailService},
 		{alertType: alert.TypeCustom, expected: alertingConfig.Custom},
 		{alertType: alert.TypeDiscord, expected: alertingConfig.Discord},
 		{alertType: alert.TypeEmail, expected: alertingConfig.Email},
+		{alertType: alert.TypeGitea, expected: alertingConfig.Gitea},
 		{alertType: alert.TypeGitHub, expected: alertingConfig.GitHub},
+		{alertType: alert.TypeGitLab, expected: alertingConfig.GitLab},
 		{alertType: alert.TypeGoogleChat, expected: alertingConfig.GoogleChat},
 		{alertType: alert.TypeGotify, expected: alertingConfig.Gotify},
 		{alertType: alert.TypeJetBrainsSpace, expected: alertingConfig.JetBrainsSpace},
@@ -1908,9 +1925,10 @@ func TestGetAlertingProviderByAlertType(t *testing.T) {
 		{alertType: alert.TypePushover, expected: alertingConfig.Pushover},
 		{alertType: alert.TypeSlack, expected: alertingConfig.Slack},
 		{alertType: alert.TypeTelegram, expected: alertingConfig.Telegram},
-		{alertType: alert.TypeTwilio, expected: alertingConfig.Twilio},
 		{alertType: alert.TypeTeams, expected: alertingConfig.Teams},
 		{alertType: alert.TypeTeamsWorkflows, expected: alertingConfig.TeamsWorkflows},
+		{alertType: alert.TypeTwilio, expected: alertingConfig.Twilio},
+		{alertType: alert.TypeZulip, expected: alertingConfig.Zulip},
 	}
 	for _, scenario := range scenarios {
 		t.Run(string(scenario.alertType), func(t *testing.T) {

watchdog/alerting_test.go

@@ -30,10 +30,12 @@ func TestHandleAlerting(t *testing.T) {
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			Custom: &custom.AlertProvider{
+				DefaultConfig: custom.Config{
 					URL:    "https://twin.sh/health",
 					Method: "GET",
 				},
 			},
+		},
 	}
 	enabled := true
 	ep := &endpoint.Endpoint{
@@ -108,10 +110,12 @@ func TestHandleAlertingWhenTriggeredAlertIsAlmostResolvedButendpointStartFailing
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			Custom: &custom.AlertProvider{
+				DefaultConfig: custom.Config{
 					URL:    "https://twin.sh/health",
 					Method: "GET",
 				},
 			},
+		},
 	}
 	enabled := true
 	ep := &endpoint.Endpoint{
@@ -141,10 +145,12 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedButSendOnResolvedIsFalse(t *t
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			Custom: &custom.AlertProvider{
+				DefaultConfig: custom.Config{
 					URL:    "https://twin.sh/health",
 					Method: "GET",
 				},
 			},
+		},
 	}
 	enabled := true
 	disabled := false
@@ -174,9 +180,11 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedPagerDuty(t *testing.T) {
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			PagerDuty: &pagerduty.AlertProvider{
+				DefaultConfig: pagerduty.Config{
 					IntegrationKey: "00000000000000000000000000000000",
 				},
 			},
+		},
 	}
 	enabled := true
 	ep := &endpoint.Endpoint{
@@ -208,10 +216,12 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedPushover(t *testing.T) {
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			Pushover: &pushover.AlertProvider{
+				DefaultConfig: pushover.Config{
 					ApplicationToken: "000000000000000000000000000000",
 					UserKey:          "000000000000000000000000000000",
 				},
 			},
+		},
 	}
 	enabled := true
 	ep := &endpoint.Endpoint{
@@ -250,25 +260,30 @@ func TestHandleAlertingWithProviderThatReturnsAnError(t *testing.T) {
 			AlertType: alert.TypeCustom,
 			AlertingConfig: &alerting.Config{
 				Custom: &custom.AlertProvider{
+					DefaultConfig: custom.Config{
 						URL:    "https://twin.sh/health",
 						Method: "GET",
 					},
 				},
 			},
+		},
 		{
 			Name:      "discord",
 			AlertType: alert.TypeDiscord,
 			AlertingConfig: &alerting.Config{
 				Discord: &discord.AlertProvider{
+					DefaultConfig: discord.Config{
 						WebhookURL: "https://example.com",
 					},
 				},
 			},
+		},
 		{
 			Name:      "email",
 			AlertType: alert.TypeEmail,
 			AlertingConfig: &alerting.Config{
 				Email: &email.AlertProvider{
+					DefaultConfig: email.Config{
 						From:     "from@example.com",
 						Password: "hunter2",
 						Host:     "mail.example.com",
@@ -277,89 +292,107 @@ func TestHandleAlertingWithProviderThatReturnsAnError(t *testing.T) {
 					},
 				},
 			},
+		},
 		{
 			Name:      "jetbrainsspace",
 			AlertType: alert.TypeJetBrainsSpace,
 			AlertingConfig: &alerting.Config{
 				JetBrainsSpace: &jetbrainsspace.AlertProvider{
+					DefaultConfig: jetbrainsspace.Config{
 						Project:   "foo",
 						ChannelID: "bar",
 						Token:     "baz",
 					},
 				},
 			},
+		},
 		{
 			Name:      "mattermost",
 			AlertType: alert.TypeMattermost,
 			AlertingConfig: &alerting.Config{
 				Mattermost: &mattermost.AlertProvider{
+					DefaultConfig: mattermost.Config{
 						WebhookURL: "https://example.com",
 					},
 				},
 			},
+		},
 		{
 			Name:      "messagebird",
 			AlertType: alert.TypeMessagebird,
 			AlertingConfig: &alerting.Config{
 				Messagebird: &messagebird.AlertProvider{
+					DefaultConfig: messagebird.Config{
 						AccessKey:  "1",
 						Originator: "2",
 						Recipients: "3",
 					},
 				},
 			},
+		},
 		{
 			Name:      "pagerduty",
 			AlertType: alert.TypePagerDuty,
 			AlertingConfig: &alerting.Config{
 				PagerDuty: &pagerduty.AlertProvider{
+					DefaultConfig: pagerduty.Config{
 						IntegrationKey: "00000000000000000000000000000000",
 					},
 				},
 			},
+		},
 		{
 			Name:      "pushover",
 			AlertType: alert.TypePushover,
 			AlertingConfig: &alerting.Config{
 				Pushover: &pushover.AlertProvider{
+					DefaultConfig: pushover.Config{
 						ApplicationToken: "000000000000000000000000000000",
 						UserKey:          "000000000000000000000000000000",
 					},
 				},
 			},
+		},
 		{
 			Name:      "slack",
 			AlertType: alert.TypeSlack,
 			AlertingConfig: &alerting.Config{
 				Slack: &slack.AlertProvider{
+					DefaultConfig: slack.Config{
 						WebhookURL: "https://example.com",
 					},
 				},
 			},
+		},
 		{
 			Name:      "teams",
 			AlertType: alert.TypeTeams,
 			AlertingConfig: &alerting.Config{
 				Teams: &teams.AlertProvider{
+					DefaultConfig: teams.Config{
 						WebhookURL: "https://example.com",
 					},
 				},
 			},
+		},
 		{
 			Name:      "telegram",
 			AlertType: alert.TypeTelegram,
 			AlertingConfig: &alerting.Config{
 				Telegram: &telegram.AlertProvider{
+					DefaultConfig: telegram.Config{
 						Token: "1",
 						ID:    "2",
 					},
 				},
 			},
+		},
 		{
 			Name:      "twilio",
 			AlertType: alert.TypeTwilio,
 			AlertingConfig: &alerting.Config{
 				Twilio: &twilio.AlertProvider{
+					DefaultConfig: twilio.Config{
 						SID:   "1",
 						Token: "2",
 						From:  "3",
@@ -367,12 +400,13 @@ func TestHandleAlertingWithProviderThatReturnsAnError(t *testing.T) {
 					},
 				},
 			},
+		},
 		{
 			Name:      "matrix",
 			AlertType: alert.TypeMatrix,
 			AlertingConfig: &alerting.Config{
 				Matrix: &matrix.AlertProvider{
-					ProviderConfig: matrix.ProviderConfig{
+					DefaultConfig: matrix.Config{
 						ServerURL:      "https://example.com",
 						AccessToken:    "1",
 						InternalRoomID: "!a:example.com",
@@ -437,10 +471,12 @@ func TestHandleAlertingWithProviderThatOnlyReturnsErrorOnResolve(t *testing.T) {
 	cfg := &config.Config{
 		Alerting: &alerting.Config{
 			Custom: &custom.AlertProvider{
+				DefaultConfig: custom.Config{
 					URL:    "https://twin.sh/health",
 					Method: "GET",
 				},
 			},
+		},
 	}
 	enabled := true
 	ep := &endpoint.Endpoint{