Google Managed Alertmanager¶

This guide shows how to forward alerts from Google Managed Prometheus (GMP) managed Alertmanager to Robusta using Robusta's generic Alertmanager webhook.

Note

Every alert must carry a cluster_name label. Set it to the Robusta cluster_name configured for the target cluster, or use external when the alerts do not belong to a specific runner.

For configuring metric querying from Google Managed Prometheus, see Google Managed Prometheus. For other Alertmanager integrations, see AlertManager - external or AlertManager - in-cluster.

Requirements¶

Robusta account_id and signing_key from your generated_values.yaml file.
A GMP workspace with managed Alertmanager enabled.

Configure the Alertmanager webhook¶

Apply the following Secret in the GMP namespace (default gmp-public). Replace <ACCOUNT_ID> and <SIGNING_KEY> with your credentials.

apiVersion: v1
kind: Secret
metadata:
  name: alertmanager
  namespace: gmp-public
type: Opaque
stringData:
  alertmanager.yaml: |
    receivers:
      - name: 'robusta'
        webhook_configs:
          - url: 'https://api.robusta.dev/integrations/generic/alertmanager'
            http_config:
              authorization:
                # Replace <ACCOUNT_ID> <SIGNING_KEY>, with your account_id and signing_key
                credentials: 'Bearer <ACCOUNT_ID> <SIGNING_KEY>'
            send_resolved: true

    route:
      receiver: 'robusta'
      group_by: ['...']
      group_wait: 1s
      group_interval: 1s
      repeat_interval: 4h

Ensure alerts include `cluster_name`¶

Use an OperatorConfig to add external labels to both collection and rule evaluation so every alert contains the required cluster_name label.

apiVersion: monitoring.googleapis.com/v1
kind: OperatorConfig
metadata:
  name: config
  namespace: gmp-public
collection:
  externalLabels:
    cluster_name: gmp-demo-cluster   # Match your Robusta cluster_name, or use "external"
    location: us-central1-c
    project_id: my-gcp-project
rules:
  externalLabels:
    cluster_name: gmp-demo-cluster
    location: us-central1-c
    project_id: my-gcp-project

Deploy a demo alert¶

Create a simple alerting rule to confirm delivery to Robusta.

apiVersion: monitoring.googleapis.com/v1
kind: Rules
metadata:
  name: test-alert
  namespace: gmp-public
spec:
  groups:
    - name: test
      interval: 30s
      rules:
        - alert: TestAlertForGCPAlertmanager
          expr: vector(1)
          for: 0m
          labels:
            severity: warning
          annotations:
            summary: "Test alert to verify Alertmanager webhook"
            description: "This is a test alert. Delete the Rules resource to stop it."

Optional: verify credentials with curl¶

You can manually validate the webhook and credentials by posting a sample alert:

curl -X POST 'https://api.robusta.dev/integrations/generic/alertmanager' \
  -H 'Authorization: Bearer <ACCOUNT_ID> <SIGNING_KEY>' \
  -H 'Content-Type: application/json' \
  -d '{
  "externalURL": "https://console.cloud.google.com/monitoring",
  "groupKey": "gmp/test-alert:gmp-webhook-test-001",
  "version": "1",
  "status": "firing",
  "receiver": "robusta",
  "alerts": [
    {
      "status": "firing",
      "startsAt": "2026-01-13T13:30:50Z",
      "endsAt": "1970-01-01T00:00:00Z",
      "generatorURL": "https://console.cloud.google.com/monitoring",
      "source": "GMP",
      "description": "Test alert to verify GMP Alertmanager webhook configuration",
      "fingerprint": "gmp-test-alert-12345",
      "annotations": {
        "summary": "GMP Webhook Test Alert",
        "description": "If you see this in Robusta, the webhook URL and credentials are working correctly!"
      },
      "labels": {
        "cluster_name": "external",
        "cluster": "external",
        "alertname": "GMP_WebhookTest",
        "severity": "warning",
        "namespace": "gmp-public",
        "source": "gmp-managed-alertmanager"
      }
    }
  ]
}'

You should see the test alert in Robusta shortly after applying the resources or running the curl command.