Release Infrastructure

Add unless: condition to any new workflow

This is a brain dump of the infrastructure we use to release React-Native.

We use CircleCI workflows to publish our release to npm. Here are some brief points about that:

• CircleCI allows configuration of the following (ordered from largest superset to smallest)
  • pipelines - We only have one, react-native
  • workflows - These are the ones configured here
  • jobs - These are configured here
  • steps - Every job has a certain number of steps
• We have 2 workflows dedicated to releases: package_release, publish_release
• We first run package_release that basically just runs this script: https://github.com/facebook/react-native/blob/main/scripts/prepare-package-for-release.js
• In prepare-package-for-release.js we commit the changes, which triggers the publish_release workflow. CircleCI allows triggers of git tags or branch pushes

To trigger package_release workflow, we leverage the CircleCI API. However, there are limitations to the CircleCI API where you cannot trigger a workflow individually, you can only trigger at a pipeline level.

The suggestion to trigger a single workflow is to add a conditional on every other workflow that is always true. See this: https://support.circleci.com/hc/en-us/articles/360050351292-How-to-trigger-a-workflow-via-CircleCI-API-v2

**Important ** That means that whenever you add a new workflow, you should add:

  my_new_workflow:
    unless: << pipeline.parameters.run_package_release_workflow_only >>
    ...