Monitor GitHub Actions Scheduled Workflows with Alert24

GitHub Actions scheduled workflows (on: schedule) run silently. If a workflow is disabled, the schedule is misconfigured, or GitHub's scheduler has a hiccup, you won't know — unless you have a heartbeat. Alert24 heartbeat checks detect when your scheduled workflows stop firing.

Before you start

1. In Alert24, go to Monitoring → Add check → Heartbeat
2. Name it after your workflow (e.g., "Nightly report workflow")
3. Set Expected interval to match your cron schedule, plus some buffer:
   • Hourly → 3600 seconds
   • Daily → 86400 seconds
4. Set Grace period to at least 15 minutes (GitHub's scheduler can run up to 15 min late)
5. Save and copy the heartbeat URL

Add the ping as the last step

# .github/workflows/nightly-report.yml
name: Nightly report

on:
  schedule:
    - cron: '0 3 * * *'  # 3am UTC daily

jobs:
  run-report:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Generate report
        run: python scripts/generate_report.py

      - name: Upload to S3
        run: aws s3 sync ./reports s3://my-bucket/reports/

      - name: Ping Alert24 heartbeat
        if: success()
        run: curl -fsS --retry 3 ${{ secrets.ALERT24_HEARTBEAT_URL }}

Store your heartbeat URL as a GitHub Actions secret (ALERT24_HEARTBEAT_URL) rather than embedding the token directly.

Why use a secret for the URL

The heartbeat URL contains a token that identifies your check. While the token only grants the ability to record heartbeats (not read or write anything else), keeping it in a secret prevents it from appearing in public workflow logs.

Monitor multiple workflows independently

Each scheduled workflow should have its own Alert24 heartbeat check:

# workflow-a.yml
- name: Ping heartbeat
  if: success()
  run: curl -fsS --retry 3 ${{ secrets.ALERT24_HB_WORKFLOW_A }}

# workflow-b.yml
- name: Ping heartbeat
  if: success()
  run: curl -fsS --retry 3 ${{ secrets.ALERT24_HB_WORKFLOW_B }}

Tips

• if: success(): This ensures the heartbeat only fires when all previous steps pass. A failed step → no ping → Alert24 fires an incident.
• GitHub's scheduler: GitHub schedules workflows with up to 15-minute delay during peak times. Set your grace period to at least 15 minutes to avoid false incidents.
• Disabled repositories: If a GitHub repository is archived, scheduled workflows stop running. Alert24 will catch this after one missed interval.
• Workflow run limits: GitHub's free tier has monthly workflow run limits. If you hit the limit, workflows stop and Alert24 fires an incident — which is exactly the behavior you want.