Slack notifications for GitHub Actions

Ruth Hoffmann, Max Horn, Chris Jefferson, Olexandr Konovalov, Sergio Siccha, and Wilf Wilson have access to the app GAP GH Actions Notifications. If you have access, then you can access the app via

https://api.slack.com/apps
-> Your Apps

The only feature that is needed is the Incoming Webhooks. On the Incoming Webhooks page, the webhook URLs can be managed at the bottom of the page. The webhook URLs must be stored in the gap-system/gap repository as a secret. It can then be used in an action via

- name: Send message to slack workspace
  uses: act10ns/slack@e4e71685b9b239384b0f676a63c32367f59c2522
  with: 
    status: ${{ job.status }}
  env:
    SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}