This sample shows how to automatically post GitHub commits to a Slack channel using an HTTPS Cloud Function.

Further reading:

• Slack Webhooks API: https://api.slack.com/incoming-webhooks
• Firebase SDK: https://firebase.google.com/docs/functions
• GitHub Webhooks: https://developer.github.com/webhooks/creating/

See file functions/index.js for the code.

The dependencies are listed in functions/package.json.

To test this integration:

• Create a Firebase Project using the Firebase Developer Console
• Enable billing on your project by switching to the Blaze plan. See pricing for more details. This is required to be able to do requests to non-Google services.
• Configure this sample to use your project using firebase use --add and select your project.
• Install dependencies locally by running: cd functions; npm install; cd -
• Add a WebHook to your GitHub repo with the following settings:
  • Payload URL: https://us-central1-<FIREBASE_PROJECT_ID>.cloudfunctions.net/githubWebhook
  • Content type: application/json
  • Secret: A_SECRET_YOU_DEFINE
  • Which events would you like to trigger this webhook? Just the push event.
• Add an Incoming Webhook to your Slack channel and take note of the Webhook URL.
• Set the slack.webhook_url and github.secret Google Cloud environment variables to match the email and password of the Gmail account used to send emails. For this use:

  firebase functions:config:set slack.webhook_url="https://hooks.slack.com/services/..." github.secret="A_SECRET_YOU_DEFINED_WHEN_SETTING_UP_THE_GITHUB_WEBHOOK"
• Deploy your project using firebase deploy
• Push a commit to your GitHub repo