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Alertmanager

Overview​

You can forward alerts from Prometheus Alertmanager a to Causely by adding a webhook receiver. Once connected, Causely ingests your existing alerts, links them to the right services, and applies causal analysis to show the real underlying issues.

This means you can:

  • Keep using your current alerting rules.
  • See alerts mapped to services and dependencies inside Causely.
  • Automatically identify which alerts are symptoms and which point to the actual causes.

Add Causely as a webhook receiver in Alertmanager​

If you are using the Prometheus Operator, add the following AlertmanagerConfig to forward alerts to Causely’s mediator.

kind: AlertmanagerConfig
spec:
  route:
    group_by: ['alertname', 'pod', 'namespace'] # how alerts are grouped
    repeat_interval: 3h # how often repeated alerts are sent
    receiver: 'causely-mediator-webhook' # send all alerts here
  receivers:
    - name: 'causely-mediator-webhook'
      webhook_configs:
        - url: 'http://mediator.causely:9093/api/v1/alerts' # mediator endpoint
          send_resolved: true # send firing + resolved states

Enabling Alertmanager as a Data Source​

Add the following to your values.yaml to enable Alertmanager ingestion in the mediator:

mediator:
  alertmanager:
    enabled: true
    port: 9093
    alert_mappings: [] # optional; see examples below

Optional: Map Alerts to Entities and Attributes​

Use alert_mappings to map Alertmanager alerts to Causely symptoms. For example, the following maps the Error Rate High alert to the RequestErrorRate_High symptom of the Service Entity:

alert_mappings:
  - alert_name: 'Error Rate High'
    symptom: 'RequestErrorRate_High'
    entity:
      service: {}
    discovery:
      - kubernetes_pod:
          namespace: 'namespace'
          pod_name: 'pod'
        conditions:
          - regex_not_match:
              label: 'pod'
              regex: '^.*-exporter.*$'

Without an alert_mappings entry, Causely will automatically map error and latency-type alerts—based on keyword matching—to the corresponding Causely Service symptoms.

Example Alert Payload​

An example alert from Alertmanager that Causely can ingest:

[
  {
    "labels": {
      "alertname": "HighErrorRate",
      "severity": "warning",
      "service": "causely-analysis",
      "namespace": "production"
    },
    "annotations": {
      "summary": "Error rate above 5% for 10m"
    },
    "startsAt": "2025-08-11T13:30:56Z",
    "endsAt": "0001-01-01T00:00:00Z",
    "generatorURL": "http://prometheus/graph?g0.expr=...",
    "fingerprint": "047235cd648d8d01"
  }
]

This alert would be mapped automatically to the high error rate symptom of the causely-analysis service.