Send Alertmanager alerts to a channel

Alertmanager sends alerts to Freesbe through a webhook receiver. You need a Freesbe admin and someone who can edit alertmanager.yml and reload Alertmanager.

Before you start

• Make the channel first, such as #infra-alerts, and add the people on call.
• Check your alerting rules have a severity label and a summary annotation. Add a description for the card’s details and runbook_url for a link.

In Freesbe

1. Open Workspace settings → Integrations & apps → Integrations → Monitoring and click Connect under Alertmanager.
2. Name it (Production Prometheus), pick the channel and Alerts to post.
3. Click Connect Alertmanager and copy the Freesbe URL. It’s shown once.

In Alertmanager

Add a receiver and route alerts to it:

receivers:
  - name: freesbe-infra
    webhook_configs:
      - url: "https://api.freesbe.net/hooks/monitoring/alertmanager/…"
        send_resolved: true

route:
  receiver: default
  routes:
    - receiver: freesbe-infra
      matchers:
        - team = "infra"
      continue: true

send_resolved: true turns cards green. continue: true keeps sending the alerts to your other receivers too. Then reload Alertmanager (curl -X POST http://localhost:9093/-/reload).

Turn on the Silence button (optional)

Freesbe silences alerts through Alertmanager’s API, so it needs Alertmanager reachable over HTTPS from the internet, usually behind a proxy that asks for a sign-in. In the connection’s settings, fill in Alertmanager address and, in API token, the proxy’s bearer token or user:password. Freesbe checks it before saving.

Check it works

Open the connection’s ⋯ menu and click Send a test alert for a sample card, or fire a real test alert with amtool alert add test_alert severity=warning --annotation=summary="Test from Prometheus".

See Grafana and Alertmanager for everything the cards show.