Implement container health alerts (#1679)

* Implement container health alerts, including a database migration for alert names and UI updates.

* Add bulk container alerts and improve alerting logic

* Implement container-specific alerts with new database collections, API endpoints, and UI components.

internal/alerts/alerts_api.go

@@ -117,3 +117,119 @@ func DeleteUserAlerts(e *core.RequestEvent) error {
 
 	return e.JSON(http.StatusOK, map[string]any{"success": true, "count": numDeleted})
 }
+
+// UpsertUserContainerAlerts handles API request to create or update container alerts for a user
+// across multiple containers (POST /api/beszel/user-container-alerts)
+func UpsertUserContainerAlerts(e *core.RequestEvent) error {
+	userID := e.Auth.Id
+
+	reqData := struct {
+		Min        uint8    `json:"min"`
+		Value      float64  `json:"value"`
+		Name       string   `json:"name"`
+		Systems    []string `json:"systems"`
+		Containers []string `json:"containers"`
+		Overwrite  bool     `json:"overwrite"`
+	}{}
+	err := e.BindBody(&reqData)
+	if err != nil || userID == "" || reqData.Name == "" || len(reqData.Systems) == 0 || len(reqData.Containers) == 0 {
+		return e.BadRequestError("Bad data", err)
+	}
+
+	containerAlertsCollection, err := e.App.FindCachedCollectionByNameOrId("container_alerts")
+	if err != nil {
+		return err
+	}
+
+	err = e.App.RunInTransaction(func(txApp core.App) error {
+		for _, systemId := range reqData.Systems {
+			for _, containerId := range reqData.Containers {
+				// find existing matching alert
+				alertRecord, err := txApp.FindFirstRecordByFilter(containerAlertsCollection,
+					"system={:system} && container={:container} && name={:name} && user={:user}",
+					dbx.Params{"system": systemId, "container": containerId, "name": reqData.Name, "user": userID})
+
+				if err != nil && !errors.Is(err, sql.ErrNoRows) {
+					return err
+				}
+
+				// skip if alert already exists and overwrite is not set
+				if !reqData.Overwrite && alertRecord != nil {
+					continue
+				}
+
+				// create new alert if it doesn't exist
+				if alertRecord == nil {
+					alertRecord = core.NewRecord(containerAlertsCollection)
+					alertRecord.Set("user", userID)
+					alertRecord.Set("system", systemId)
+					alertRecord.Set("container", containerId)
+					alertRecord.Set("name", reqData.Name)
+				}
+
+				alertRecord.Set("value", reqData.Value)
+				alertRecord.Set("min", reqData.Min)
+
+				if err := txApp.SaveNoValidate(alertRecord); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+
+	if err != nil {
+		return err
+	}
+
+	return e.JSON(http.StatusOK, map[string]any{"success": true})
+}
+
+// DeleteUserContainerAlerts handles API request to delete container alerts for a user
+// across multiple containers (DELETE /api/beszel/user-container-alerts)
+func DeleteUserContainerAlerts(e *core.RequestEvent) error {
+	userID := e.Auth.Id
+
+	reqData := struct {
+		AlertName  string   `json:"name"`
+		Systems    []string `json:"systems"`
+		Containers []string `json:"containers"`
+	}{}
+	err := e.BindBody(&reqData)
+	if err != nil || userID == "" || reqData.AlertName == "" || len(reqData.Systems) == 0 || len(reqData.Containers) == 0 {
+		return e.BadRequestError("Bad data", err)
+	}
+
+	var numDeleted uint16
+
+	err = e.App.RunInTransaction(func(txApp core.App) error {
+		for _, systemId := range reqData.Systems {
+			for _, containerId := range reqData.Containers {
+				// Find existing alert to delete
+				alertRecord, err := txApp.FindFirstRecordByFilter("container_alerts",
+					"system={:system} && container={:container} && name={:name} && user={:user}",
+					dbx.Params{"system": systemId, "container": containerId, "name": reqData.AlertName, "user": userID})
+
+				if err != nil {
+					if errors.Is(err, sql.ErrNoRows) {
+						// alert doesn't exist, continue to next container
+						continue
+					}
+					return err
+				}
+
+				if err := txApp.Delete(alertRecord); err != nil {
+					return err
+				}
+				numDeleted++
+			}
+		}
+		return nil
+	})
+
+	if err != nil {
+		return err
+	}
+
+	return e.JSON(http.StatusOK, map[string]any{"success": true, "count": numDeleted})
+}