cascade-example-rollback-dispatch

A minimal cascade example whose purpose is to prove the repository_dispatch rollback entry point live.

The manifest declares two environments (staging, then prod), one build, and one deploy, and opts the generated rollback workflow into a repository_dispatch trigger:

rollback:
  repository_dispatch:
    types: [rollback-requested]

With that opt-in, cascade-rollback.yaml carries both the manual (workflow_dispatch) and the external (repository_dispatch) entry points, and each rollback parameter is read as github.event.inputs.<key> || github.event.client_payload.<key> so an external system can drive the same rollback by calling the dispatches API.

Rollback targets prod, the promoted-into environment. The first environment (staging) tracks trunk and is never promoted into, so it carries no rollback history and is reverted with a merge to trunk rather than a rollback. prod gains its history from promotion, which is why the ring has two environments.

What the scenario suite proves

scenario-suite.yaml seeds staging on a merge and promotes it to prod, advances staging and promotes a second version to prod (leaving the earlier version in prod's deploy-history ring), then fires a real repository_dispatch rollback:

gh api "repos/$REPO/dispatches" -X POST \
  -f event_type=rollback-requested \
  -f 'client_payload[environment]=prod' \
  -F 'client_payload[dry_run]=false'

It then asserts the real effect: prod reverts to the prior deploy's SHA and version and is marked diverged (ref=rollback/prod). This is the only live coverage of the client_payload coalesce path.

Layout

• .github/manifest.yaml - the cascade manifest (staging then prod, rollback dispatch on).
• .github/workflows/orchestrate.yaml, promote.yaml, cascade-hotfix.yaml, cascade-rollback.yaml - generated by cascade generate-workflow; do not edit by hand.
• .github/workflows/build-app.yaml, deploy-app.yaml - the build and deploy callbacks the pipeline drives.
• .github/workflows/scenario-suite.yaml - the live validation driver.
• src/ - the source of record a merge changes to drive orchestrate.

Regenerate the workflows after a manifest change:

cascade generate-workflow --config .github/manifest.yaml --force