pass custom headers to http notifications. (#357)

* pass custom headers to http notifications.

* pass custom headers to http notifications.

* add notifiers headers test.

core/internal/notifier/http.go

@@ -175,6 +175,10 @@ func (module *HTTPNotifier) Notify(status *protocol.ConsumerGroupStatus, eventID
 	}
 	req.Header.Set("Content-Type", "application/json")
 
+	for header, value := range viper.GetStringMapString("notifier." + module.name + ".headers") {
+		req.Header.Set(header, value)
+	}
+
 	resp, err := module.httpClient.Do(req)
 	if err != nil {
 		logger.Error("failed to send", zap.Error(err))

core/internal/notifier/http_test.go

@@ -40,6 +40,7 @@ func fixtureHTTPNotifier() *HTTPNotifier {
 	viper.Set("notifier.test.template-open", "template_open")
 	viper.Set("notifier.test.template-close", "template_close")
 	viper.Set("notifier.test.send-close", false)
+	viper.Set("notifier.test.headers", map[string]string{"Token": "testtoken"})
 
 	return &module
 }
@@ -91,6 +92,10 @@ func TestHttpNotifier_Notify_Open(t *testing.T) {
 		assert.Len(t, headers, 1, "Expected to receive exactly one Content-Type header")
 		assert.Equalf(t, "application/json", headers[0], "Expected Content-Type header to be 'application/json', not '%v'", headers[0])
 
+		tokenHeaders, ok := r.Header["Token"]
+		assert.True(t, ok, "Expected to receive Token header")
+		assert.Equalf(t, "testtoken", tokenHeaders[0], "Expected Token header to be 'testtoken', not '%v'", tokenHeaders[0])
+
 		decoder := json.NewDecoder(r.Body)
 		var req HTTPRequest
 		err := decoder.Decode(&req)
@@ -138,6 +143,10 @@ func TestHttpNotifier_Notify_Close(t *testing.T) {
 		assert.Len(t, headers, 1, "Expected to receive exactly one Content-Type header")
 		assert.Equalf(t, "application/json", headers[0], "Expected Content-Type header to be 'application/json', not '%v'", headers[0])
 
+		tokenHeaders, ok := r.Header["Token"]
+		assert.True(t, ok, "Expected to receive Token header")
+		assert.Equalf(t, "testtoken", tokenHeaders[0], "Expected Token header to be 'testtoken', not '%v'", tokenHeaders[0])
+
 		decoder := json.NewDecoder(r.Body)
 		var req HTTPRequest
 		err := decoder.Decode(&req)