Close #74: Add maintenance window

README.md

@@ -47,6 +47,7 @@ For more details, see [Usage](#usage)
     - [Configuring Twilio alerts](#configuring-twilio-alerts)
     - [Configuring custom alerts](#configuring-custom-alerts)
     - [Setting a default alert](#setting-a-default-alert)
+  - [Maintenance](#maintenance)
 - [Deployment](#deployment)
   - [Docker](#docker)
   - [Helm Chart](#helm-chart)
@@ -736,6 +737,37 @@ services:
       - type: pagerduty
 ```
 
+### Maintenance
+If you have maintenance windows, you may not want to be annoyed by alerts. 
+To do that, you'll have to use the maintenance configuration:
+
+| Parameter               | Description                                                                   | Default         |
+|:----------------------- |:----------------------------------------------------------------------------- |:--------------- |
+| `maintenance.enabled`   | Whether the maintenance period is enabled                                     | `true`          |
+| `maintenance.start`     | Time at which the maintenance window starts in `hh:mm` format (e.g. `23:00`)  | Required `""`   |
+| `maintenance.duration`  | Duration of the maintenance window (e.g. `1h`, `30m`)                         | Required `""`   |
+| `maintenance.every`     | Days on which the maintenance period applies (e.g. `[Monday, Thursday]`).<br />If left empty, the maintenance window applies every day | `[]` |
+**Note that the maintenance configuration uses UTC.**
+
+
+Here's an example:
+```yaml
+maintenance:
+  start: 23:00
+  duration: 1h
+  every: [Monday, Thursday]
+```
+Note that you can also specify each day on separate lines:
+```yaml
+maintenance:
+  start: 23:00
+  duration: 1h
+  every:
+    - Monday
+    - Thursday
+```
+
+
 
 ## Deployment
 Many examples can be found in the [examples](examples) folder, but this section will focus on the most popular ways of deploying Gatus.

config/config.go

@@ -10,6 +10,7 @@ import (
 	"github.com/TwinProduction/gatus/alerting"
 	"github.com/TwinProduction/gatus/alerting/alert"
 	"github.com/TwinProduction/gatus/alerting/provider"
+	"github.com/TwinProduction/gatus/config/maintenance"
 	"github.com/TwinProduction/gatus/core"
 	"github.com/TwinProduction/gatus/security"
 	"github.com/TwinProduction/gatus/storage"
@@ -82,6 +83,9 @@ type Config struct {
 	// UI is the configuration for the UI
 	UI *UIConfig `yaml:"ui"`
 
+	// Maintenance is the configuration for creating a maintenance window in which no alerts are sent
+	Maintenance *maintenance.Config `yaml:"maintenance"`
+
 	filePath        string    // path to the file from which config was loaded from
 	lastFileModTime time.Time // last modification time
 }
@@ -172,6 +176,9 @@ func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 		if err := validateUIConfig(config); err != nil {
 			return nil, err
 		}
+		if err := validateMaintenanceConfig(config); err != nil {
+			return nil, err
+		}
 		if err := validateStorageConfig(config); err != nil {
 			return nil, err
 		}
@@ -201,6 +208,17 @@ func validateStorageConfig(config *Config) error {
 	return nil
 }
 
+func validateMaintenanceConfig(config *Config) error {
+	if config.Maintenance == nil {
+		config.Maintenance = maintenance.GetDefaultConfig()
+	} else {
+		if err := config.Maintenance.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func validateUIConfig(config *Config) error {
 	if config.UI == nil {
 		config.UI = GetDefaultUIConfig()

config/config_test.go

@@ -43,6 +43,11 @@ func TestParseAndValidateConfigBytes(t *testing.T) {
 	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
 storage:
   file: %s
+maintenance:
+  enabled: true
+  start: 00:00
+  duration: 4h
+  every: [Monday, Thursday]
 ui:
   title: Test
 services:
@@ -79,6 +84,9 @@ services:
 	if config.UI == nil || config.UI.Title != "Test" {
 		t.Error("Expected Config.UI.Title to be Test")
 	}
+	if mc := config.Maintenance; mc == nil || mc.Start != "00:00" || !mc.IsEnabled() || mc.Duration != 4*time.Hour || len(mc.Every) != 2 {
+		t.Error("Expected Config.Maintenance to be configured properly")
+	}
 	if len(config.Services) != 3 {
 		t.Error("Should have returned two services")
 	}

config/maintenance/maintenance.go

@@ -0,0 +1,133 @@
+package maintenance
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var (
+	errInvalidMaintenanceStartFormat = errors.New("invalid maintenance start format: must be hh:mm, between 00:00 and 23:59 inclusively (e.g. 23:00)")
+	errInvalidMaintenanceDuration    = errors.New("invalid maintenance duration: must be bigger than 0 (e.g. 30m)")
+	errInvalidDayName                = fmt.Errorf("invalid value specified for 'on'. supported values are %s", longDayNames)
+
+	longDayNames = []string{
+		"Sunday",
+		"Monday",
+		"Tuesday",
+		"Wednesday",
+		"Thursday",
+		"Friday",
+		"Saturday",
+	}
+)
+
+// Config allows for the configuration of a maintenance period.
+// During this maintenance period, no alerts will be sent.
+//
+// Uses UTC.
+type Config struct {
+	Enabled  *bool         `yaml:"enabled"`  // Whether the maintenance period is enabled. Enabled by default if nil.
+	Start    string        `yaml:"start"`    // Time at which the maintenance period starts (e.g. 23:00)
+	Duration time.Duration `yaml:"duration"` // Duration of the maintenance period (e.g. 4h)
+
+	// Every is a list of days of the week during which maintenance period applies.
+	// See longDayNames for list of valid values.
+	// Every day if empty.
+	Every []string `yaml:"every"`
+
+	durationToStartFromMidnight time.Duration
+	timeLocation                *time.Location
+}
+
+func GetDefaultConfig() *Config {
+	defaultValue := false
+	return &Config{
+		Enabled: &defaultValue,
+	}
+}
+
+// IsEnabled returns whether maintenance is enabled or not
+func (c Config) IsEnabled() bool {
+	if c.Enabled == nil {
+		return true
+	}
+	return *c.Enabled
+}
+
+// ValidateAndSetDefaults validates the maintenance configuration and sets the default values if necessary.
+//
+// Must be called once in the application's lifecycle before IsUnderMaintenance is called, since it
+// also sets durationToStartFromMidnight.
+func (c *Config) ValidateAndSetDefaults() error {
+	if c == nil || !c.IsEnabled() {
+		// Don't waste time validating if maintenance is not enabled.
+		return nil
+	}
+	for _, day := range c.Every {
+		isDayValid := false
+		for _, longDayName := range longDayNames {
+			if day == longDayName {
+				isDayValid = true
+				break
+			}
+		}
+		if !isDayValid {
+			return errInvalidDayName
+		}
+	}
+	var err error
+	c.durationToStartFromMidnight, err = hhmmToDuration(c.Start)
+	if err != nil {
+		return err
+	}
+	if c.Duration <= 0 || c.Duration >= 24*time.Hour {
+		return errInvalidMaintenanceDuration
+	}
+	return nil
+}
+
+// IsUnderMaintenance checks whether the services that Gatus monitors are within the configured maintenance window
+func (c Config) IsUnderMaintenance() bool {
+	if !c.IsEnabled() {
+		return false
+	}
+	now := time.Now().UTC()
+	dayWhereMaintenancePeriodWouldStart := now.Add(-c.Duration).Truncate(24 * time.Hour)
+	hasMaintenanceEveryDay := len(c.Every) == 0
+	hasMaintenancePeriodScheduledForThatWeekday := sort.SearchStrings(c.Every, dayWhereMaintenancePeriodWouldStart.Weekday().String()) != len(c.Every)
+	if !hasMaintenanceEveryDay && !hasMaintenancePeriodScheduledForThatWeekday {
+		// The day when the maintenance period would start is not scheduled
+		// to have any maintenance, so we can just return false.
+		return false
+	}
+	startOfMaintenancePeriod := dayWhereMaintenancePeriodWouldStart.Add(c.durationToStartFromMidnight)
+	endOfMaintenancePeriod := startOfMaintenancePeriod.Add(c.Duration)
+	return now.After(startOfMaintenancePeriod) && now.Before(endOfMaintenancePeriod)
+}
+
+func hhmmToDuration(s string) (time.Duration, error) {
+	if len(s) != 5 {
+		return 0, errInvalidMaintenanceStartFormat
+	}
+	var hours, minutes int
+	var err error
+	if hours, err = extractNumericalValueFromPotentiallyZeroPaddedString(s[:2]); err != nil {
+		return 0, err
+	}
+	if minutes, err = extractNumericalValueFromPotentiallyZeroPaddedString(s[3:5]); err != nil {
+		return 0, err
+	}
+	duration := (time.Duration(hours) * time.Hour) + (time.Duration(minutes) * time.Minute)
+	if hours < 0 || hours > 23 || minutes < 0 || minutes > 59 || duration < 0 || duration >= 24*time.Hour {
+		return 0, errInvalidMaintenanceStartFormat
+	}
+	return duration, nil
+}
+
+func extractNumericalValueFromPotentiallyZeroPaddedString(s string) (int, error) {
+	return strconv.Atoi(strings.TrimPrefix(s, "0"))
+}

config/maintenance/maintenance_test.go

@@ -0,0 +1,193 @@
+package maintenance
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"testing"
+	"time"
+)
+
+func TestGetDefaultConfig(t *testing.T) {
+	if *GetDefaultConfig().Enabled {
+		t.Fatal("expected default config to be disabled by default")
+	}
+}
+
+func TestConfig_Validate(t *testing.T) {
+	yes, no := true, false
+	scenarios := []struct {
+		name          string
+		cfg           *Config
+		expectedError error
+	}{
+		{
+			name:          "nil",
+			cfg:           nil,
+			expectedError: nil,
+		},
+		{
+			name: "disabled",
+			cfg: &Config{
+				Enabled: &no,
+			},
+			expectedError: nil,
+		},
+		{
+			name: "invalid-day",
+			cfg: &Config{
+				Every: []string{"invalid-day"},
+			},
+			expectedError: errInvalidDayName,
+		},
+		{
+			name: "invalid-day",
+			cfg: &Config{
+				Every: []string{"invalid-day"},
+			},
+			expectedError: errInvalidDayName,
+		},
+		{
+			name: "invalid-start-format",
+			cfg: &Config{
+				Start: "0000",
+			},
+			expectedError: errInvalidMaintenanceStartFormat,
+		},
+		{
+			name: "invalid-start-hours",
+			cfg: &Config{
+				Start: "25:00",
+			},
+			expectedError: errInvalidMaintenanceStartFormat,
+		},
+		{
+			name: "invalid-start-minutes",
+			cfg: &Config{
+				Start: "0:61",
+			},
+			expectedError: errInvalidMaintenanceStartFormat,
+		},
+		{
+			name: "invalid-start-minutes-non-numerical",
+			cfg: &Config{
+				Start: "00:zz",
+			},
+			expectedError: strconv.ErrSyntax,
+		},
+		{
+			name: "invalid-start-hours-non-numerical",
+			cfg: &Config{
+				Start: "zz:00",
+			},
+			expectedError: strconv.ErrSyntax,
+		},
+		{
+			name: "invalid-duration",
+			cfg: &Config{
+				Start:    "23:00",
+				Duration: 0,
+			},
+			expectedError: errInvalidMaintenanceDuration,
+		},
+		{
+			name: "every-day-at-2300",
+			cfg: &Config{
+				Start:    "23:00",
+				Duration: time.Hour,
+			},
+			expectedError: nil,
+		},
+		{
+			name: "every-monday-at-0000",
+			cfg: &Config{
+				Start:    "00:00",
+				Duration: 30 * time.Minute,
+				Every:    []string{"Monday"},
+			},
+			expectedError: nil,
+		},
+		{
+			name: "every-friday-and-sunday-at-0000-explicitly-enabled",
+			cfg: &Config{
+				Enabled:  &yes,
+				Start:    "08:00",
+				Duration: 8 * time.Hour,
+				Every:    []string{"Friday", "Sunday"},
+			},
+			expectedError: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			err := scenario.cfg.ValidateAndSetDefaults()
+			if !errors.Is(err, scenario.expectedError) {
+				t.Errorf("expected %v, got %v", scenario.expectedError, err)
+			}
+		})
+	}
+}
+
+func TestConfig_IsUnderMaintenance(t *testing.T) {
+	yes, no := true, false
+	now := time.Now().UTC()
+	scenarios := []struct {
+		name     string
+		cfg      *Config
+		expected bool
+	}{
+		{
+			name: "disabled",
+			cfg: &Config{
+				Enabled: &no,
+			},
+			expected: false,
+		},
+		{
+			name: "under-maintenance-explicitly-enabled",
+			cfg: &Config{
+				Enabled:  &yes,
+				Start:    fmt.Sprintf("%02d:00", now.Hour()),
+				Duration: 2 * time.Hour,
+			},
+			expected: true,
+		},
+		{
+			name: "under-maintenance",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", now.Hour()),
+				Duration: 2 * time.Hour,
+			},
+			expected: true,
+		},
+		{
+			name: "not-under-maintenance",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", now.Add(-5*time.Hour).Hour()),
+				Duration: time.Hour,
+			},
+			expected: false,
+		},
+		{
+			name: "not-under-maintenance-today",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", now.Hour()),
+				Duration: time.Hour,
+				Every:    []string{now.Add(48 * time.Hour).Weekday().String()},
+			},
+			expected: false,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			if scenario.cfg.ValidateAndSetDefaults() != nil {
+				t.Fatal("validation shouldn't have returned an error")
+			}
+			isUnderMaintenance := scenario.cfg.IsUnderMaintenance()
+			if isUnderMaintenance != scenario.expected {
+				t.Errorf("expected %v, got %v", scenario.expected, isUnderMaintenance)
+				t.Logf("start=%v; duration=%v; now=%v", scenario.cfg.Start, scenario.cfg.Duration, time.Now().UTC())
+			}
+		})
+	}
+}

watchdog/watchdog.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/TwinProduction/gatus/alerting"
 	"github.com/TwinProduction/gatus/config"
+	"github.com/TwinProduction/gatus/config/maintenance"
 	"github.com/TwinProduction/gatus/core"
 	"github.com/TwinProduction/gatus/metric"
 	"github.com/TwinProduction/gatus/storage"
@@ -27,17 +28,17 @@ func Monitor(cfg *config.Config) {
 	ctx, cancelFunc = context.WithCancel(context.Background())
 	for _, service := range cfg.Services {
 		if service.IsEnabled() {
-			// To prevent multiple requests from running at the same time, we'll wait for a little bit before each iteration
+			// To prevent multiple requests from running at the same time, we'll wait for a little before each iteration
 			time.Sleep(1111 * time.Millisecond)
-			go monitor(service, cfg.Alerting, cfg.DisableMonitoringLock, cfg.Metrics, cfg.Debug, ctx)
+			go monitor(service, cfg.Alerting, cfg.Maintenance, cfg.DisableMonitoringLock, cfg.Metrics, cfg.Debug, ctx)
 		}
 	}
 }
 
 // monitor monitors a single service in a loop
-func monitor(service *core.Service, alertingConfig *alerting.Config, disableMonitoringLock, enabledMetrics, debug bool, ctx context.Context) {
+func monitor(service *core.Service, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, disableMonitoringLock, enabledMetrics, debug bool, ctx context.Context) {
 	// Run it immediately on start
-	execute(service, alertingConfig, disableMonitoringLock, enabledMetrics, debug)
+	execute(service, alertingConfig, maintenanceConfig, disableMonitoringLock, enabledMetrics, debug)
 	// Loop for the next executions
 	for {
 		select {
@@ -45,12 +46,12 @@ func monitor(service *core.Service, alertingConfig *alerting.Config, disableMoni
 			log.Printf("[watchdog][monitor] Canceling current execution of group=%s; service=%s", service.Group, service.Name)
 			return
 		case <-time.After(service.Interval):
-			execute(service, alertingConfig, disableMonitoringLock, enabledMetrics, debug)
+			execute(service, alertingConfig, maintenanceConfig, disableMonitoringLock, enabledMetrics, debug)
 		}
 	}
 }
 
-func execute(service *core.Service, alertingConfig *alerting.Config, disableMonitoringLock, enabledMetrics, debug bool) {
+func execute(service *core.Service, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, disableMonitoringLock, enabledMetrics, debug bool) {
 	if !disableMonitoringLock {
 		// By placing the lock here, we prevent multiple services from being monitored at the exact same time, which
 		// could cause performance issues and return inaccurate results
@@ -72,7 +73,11 @@ func execute(service *core.Service, alertingConfig *alerting.Config, disableMoni
 		len(result.Errors),
 		result.Duration.Round(time.Millisecond),
 	)
+	if !maintenanceConfig.IsUnderMaintenance() {
 		HandleAlerting(service, result, alertingConfig, debug)
+	} else if debug {
+		log.Println("[watchdog][execute] Not handling alerting because currently in the maintenance window")
+	}
 	if debug {
 		log.Printf("[watchdog][execute] Waiting for interval=%s before monitoring group=%s service=%s again", service.Interval, service.Group, service.Name)
 	}
@@ -83,7 +88,9 @@ func execute(service *core.Service, alertingConfig *alerting.Config, disableMoni
 
 // UpdateServiceStatuses updates the slice of service statuses
 func UpdateServiceStatuses(service *core.Service, result *core.Result) {
-	storage.Get().Insert(service, result)
+	if err := storage.Get().Insert(service, result); err != nil {
+		log.Println("[watchdog][UpdateServiceStatuses] Failed to insert data in storage:", err.Error())
+	}
 }
 
 // Shutdown stops monitoring all services