Fix #146: Alerting causes panic with some providers

alerting/provider/pagerduty/pagerduty.go

@@ -9,6 +9,10 @@ import (
 	"github.com/TwinProduction/gatus/core"
 )
 
+const (
+	restAPIURL = "https://events.pagerduty.com/v2/enqueue"
+)
+
 // AlertProvider is the configuration necessary for sending an alert using PagerDuty
 type AlertProvider struct {
 	IntegrationKey string `yaml:"integration-key"`
@@ -37,7 +41,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		resolveKey = ""
 	}
 	return &custom.AlertProvider{
-		URL:    "https://events.pagerduty.com/v2/enqueue",
+		URL:    restAPIURL,
 		Method: http.MethodPost,
 		Body: fmt.Sprintf(`{
   "routing_key": "%s",

client/client.go

@@ -16,7 +16,10 @@ import (
 
 // GetHTTPClient returns the shared HTTP client
 func GetHTTPClient(config *Config) *http.Client {
-	return config.GetHTTPClient()
+	if config == nil {
+		return defaultConfig.getHTTPClient()
+	}
+	return config.getHTTPClient()
 }
 
 // CanCreateTCPConnection checks whether a connection can be established with a TCP service

client/client_test.go

@@ -6,12 +6,18 @@ import (
 )
 
 func TestGetHTTPClient(t *testing.T) {
-	GetHTTPClient(&Config{
+	cfg := &Config{
 		Insecure:       false,
 		IgnoreRedirect: false,
 		Timeout:        0,
-		httpClient:     nil,
-	})
+	}
+	cfg.ValidateAndSetDefaults()
+	if GetHTTPClient(cfg) == nil {
+		t.Error("expected client to not be nil")
+	}
+	if GetHTTPClient(nil) == nil {
+		t.Error("expected client to not be nil")
+	}
 }
 
 func TestPing(t *testing.T) {

client/config.go

@@ -47,7 +47,7 @@ func (c *Config) ValidateAndSetDefaults() {
 }
 
 // GetHTTPClient return a HTTP client matching the Config's parameters.
-func (c *Config) GetHTTPClient() *http.Client {
+func (c *Config) getHTTPClient() *http.Client {
 	if c.httpClient == nil {
 		c.httpClient = &http.Client{
 			Timeout: c.Timeout,

client/config_test.go

@@ -6,10 +6,10 @@ import (
 	"time"
 )
 
-func TestConfig_GetHTTPClient(t *testing.T) {
+func TestConfig_getHTTPClient(t *testing.T) {
 	insecureConfig := &Config{Insecure: true}
 	insecureConfig.ValidateAndSetDefaults()
-	insecureClient := insecureConfig.GetHTTPClient()
+	insecureClient := insecureConfig.getHTTPClient()
 	if !(insecureClient.Transport).(*http.Transport).TLSClientConfig.InsecureSkipVerify {
 		t.Error("expected Config.Insecure set to true to cause the HTTP client to skip certificate verification")
 	}
@@ -23,7 +23,7 @@ func TestConfig_GetHTTPClient(t *testing.T) {
 
 	secureConfig := &Config{IgnoreRedirect: true, Timeout: 5 * time.Second}
 	secureConfig.ValidateAndSetDefaults()
-	secureClient := secureConfig.GetHTTPClient()
+	secureClient := secureConfig.getHTTPClient()
 	if (secureClient.Transport).(*http.Transport).TLSClientConfig.InsecureSkipVerify {
 		t.Error("expected Config.Insecure set to false to cause the HTTP client to not skip certificate verification")
 	}