Engineering Handbook

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Deployments ​

Our main platforms of choice are Heroku and Cloudflare. Using managed services helps us minimise ops tasks, and keeps us focused on the application layer.

Continuous deployment ​

Where possible we operate a continuous deployment policy, which means that changes are deployed to production as and when they are ready.

Rails app ​

When CI checks pass on main the production deployment auto-deploys.

Review apps ​

For our main codebase, we have review apps enabled. This means every PR gets its own deployment environment. When a review app is deployed, it takes a copy of the staging app database.

Staging lock policy ​

By default the staging deployment is configured to auto-deploy from the main branch (as per production). Sometimes it's necessary to upgrade a review up to staging – for instance, when the feature being tested requires a *bbcmaestro.com domain, or for testing the staging track of the mobile app.

In this instance we operate a "stacking lock" policy.

Steps ​

  1. Announce that staging has changed on #engineering-staging-lock
  2. Deploy your branch to staging
  3. (after testing) Revert staging to main
  4. Release lock on #engineering-staging-lock

Step 1: Announce staging is locked ​

  • Go to #engineering-staging-lock in Slack and type /lock
  • Select ‘Lock staging environment’
  • Fill in the form with yourself, an expected end time to your testing, and any other details for other developers, then click Submit.

Step 2: Deploy your branch to staging ​

  • Go to Heroku and find the staging deployment
  • Disable automatic deploys
  • Under ‘Manual Deploy’ select the branch you want to deploy and click ‘Deploy branch'
  • Wait for the build to finish, you can now test your code on Staging

Step 3: (after testing) revert staging back to main ​

  • Enable automatic deploys
  • After re-enabling automatic deploys you will need to manually redeploy the main branch to bring things back in line with production.

Step 4: Release the staging lock ​

  • Go to the slack channel #engineering-staging-lock
  • Click ‘Unlock now’ against your staging lock

Mobile app ​

[TODO]