Alerting: Notification channel http api enhancements (#16219)

Now returns uid in response to get notification channel by id.
Adds GET/PUT/DELETE support for notification channel by uid, 
  /api/alert-notifications/uid/:uid.
Break apart alerting and alert notification http api docs in two 
  pages and update documentation to make it up to date
  with current implementation.

Fixes #16012

pkg/api/alerting.go

@@ -208,6 +208,31 @@ func GetAlertNotificationByID(c *m.ReqContext) Response {
 		Id:    c.ParamsInt64("notificationId"),
 	}
 
+	if query.Id == 0 {
+		return Error(404, "Alert notification not found", nil)
+	}
+
+	if err := bus.Dispatch(query); err != nil {
+		return Error(500, "Failed to get alert notifications", err)
+	}
+
+	if query.Result == nil {
+		return Error(404, "Alert notification not found", nil)
+	}
+
+	return JSON(200, dtos.NewAlertNotification(query.Result))
+}
+
+func GetAlertNotificationByUID(c *m.ReqContext) Response {
+	query := &m.GetAlertNotificationsWithUidQuery{
+		OrgId: c.OrgId,
+		Uid:   c.Params("uid"),
+	}
+
+	if query.Uid == "" {
+		return Error(404, "Alert notification not found", nil)
+	}
+
 	if err := bus.Dispatch(query); err != nil {
 		return Error(500, "Failed to get alert notifications", err)
 	}
@@ -239,6 +264,17 @@ func UpdateAlertNotification(c *m.ReqContext, cmd m.UpdateAlertNotificationComma
 	return JSON(200, dtos.NewAlertNotification(cmd.Result))
 }
 
+func UpdateAlertNotificationByUID(c *m.ReqContext, cmd m.UpdateAlertNotificationWithUidCommand) Response {
+	cmd.OrgId = c.OrgId
+	cmd.Uid = c.Params("uid")
+
+	if err := bus.Dispatch(&cmd); err != nil {
+		return Error(500, "Failed to update alert notification", err)
+	}
+
+	return JSON(200, dtos.NewAlertNotification(cmd.Result))
+}
+
 func DeleteAlertNotification(c *m.ReqContext) Response {
 	cmd := m.DeleteAlertNotificationCommand{
 		OrgId: c.OrgId,
@@ -252,6 +288,19 @@ func DeleteAlertNotification(c *m.ReqContext) Response {
 	return Success("Notification deleted")
 }
 
+func DeleteAlertNotificationByUID(c *m.ReqContext) Response {
+	cmd := m.DeleteAlertNotificationWithUidCommand{
+		OrgId: c.OrgId,
+		Uid:   c.Params("uid"),
+	}
+
+	if err := bus.Dispatch(&cmd); err != nil {
+		return Error(500, "Failed to delete alert notification", err)
+	}
+
+	return Success("Notification deleted")
+}
+
 //POST /api/alert-notifications/test
 func NotificationTest(c *m.ReqContext, dto dtos.NotificationTestCommand) Response {
 	cmd := &alerting.NotificationTestCommand{

pkg/api/api.go

@@ -350,6 +350,9 @@ func (hs *HTTPServer) registerRoutes() {
 			alertNotifications.Put("/:notificationId", bind(m.UpdateAlertNotificationCommand{}), Wrap(UpdateAlertNotification))
 			alertNotifications.Get("/:notificationId", Wrap(GetAlertNotificationByID))
 			alertNotifications.Delete("/:notificationId", Wrap(DeleteAlertNotification))
+			alertNotifications.Get("/uid/:uid", Wrap(GetAlertNotificationByUID))
+			alertNotifications.Put("/uid/:uid", bind(m.UpdateAlertNotificationWithUidCommand{}), Wrap(UpdateAlertNotificationByUID))
+			alertNotifications.Delete("/uid/:uid", Wrap(DeleteAlertNotificationByUID))
 		}, reqEditorRole)
 
 		apiRoute.Get("/annotations", Wrap(GetAnnotations))