Alertmanager middleware for Uptime Kuma push monitor

What is this?

This binary allows you to use Uptime Kuma as a Dead Mans Snitch for your Prometheus Alertmanager. If your Alertmanager stops sending alerts, Uptime Kuma will send you a notification.

Why does this need an extra middleware?

Alertmanager allows you to configure webhooks to send alerts to. All webhook alerts from Alertmanager are sent using the HTTP POST method. Uptime Kuma has a Push Monitor, that listens only for HTTP GET requests. This middleware listens for POST requests on port 8081 and the /push path and forwards them to Uptime Kuma as plain GET requests.

How to use

Configure this middleware as a sidecar container in your Alertmanager deployment. Then send alerts to this middleware to forward them to Uptime Kuma.

The binary requires the following environment variables:

Variable	Description
UPTIME_KUMA_URL	The URL to your Uptime Kuma instance. This URL should be the push monitor URL.
GET_RETRIES	How often a GET request should be retried if it fails. Default is 3.

Example with kube-prometheus-stack

Configure a push monitor in your Uptime Kuma instance.

Add a secret with the Uptime Kuma push URL.

apiVersion: v1
kind: Secret
metadata:
    name: uptime-kuma-url
    namespace: monitoring
type: Opaque
stringData:
    # Required
    UPTIME_KUMA_URL: "https://uptime-kuma.example.com/api/push/XXXXXXX"
    # Optional
    GET_RETRIES: 3

Add this middleware as a sidecar container to your Alertmanager deployment. Use the secret as an environment variable.

alertmanager:
    alertmanagerSpec:
    # Sidecar middleware to push watchdog alerts to uptime-kuma
        containers:
        - name: alertmanager-uptime-kuma-push
            image: ghcr.io/natrontech/alertmanager-uptime-kuma-push:0.0.3
            ports:
            - containerPort: 8081
            envFrom:
            - secretRef:
                name: uptime-kuma-url

Add a new receiver for the Watchdog alert to your Alertmanager configuration. We don't send resolved because the Watchdog alert is always firing.

route:
    routes:
        - receiver: Dead Mans Snitch Uptime Kuma
          matchers:
            - alertname =~ "InfoInhibitor|Watchdog"
          group_wait: 0s
          group_interval: 50s
          repeat_interval: 1m
receivers:
    - name: Dead Mans Snitch Uptime Kuma
      webhook_configs:
        - url: http://localhost:8081/push
          send_resolved: false