cascade-example-primary

A worked example of a cross-repo primary managed by cascade. This repository runs its own two-environment promotion pipeline (staging then prod) while also coordinating artifacts produced in two separate source repositories.

What This Repository Shows

This primary integrates with two source repositories using the two cross-repo mechanisms cascade provides:

Mechanism	How it works here
Synchronous reusable callback	The sharedlib build calls a reusable workflow that lives in cascade-example-artifact-a (uses: ...build-shared.yaml@main). Its artifact_id output is captured during the orchestrate run.
Asynchronous External Update	After each source builds, it dispatches this repo's external-update.yaml. cascade writes {deploy_name, sha, version, artifacts} into the shared manifest under state.<env>.external.<name>.

The external block in .github/manifest.yaml declares both sources:

• cascade-example-artifact-a -> deploy name artifact-a
• cascade-example-artifact-b -> deploy name artifact-b

A shared-manifest concurrency guard (cancel_in_progress: false) serializes manifest writes so that two sources updating at the same time never lose an update.

Layout

Path	Purpose
.github/manifest.yaml	Pipeline definition (envs, builds, deploys, external block, release_token).
.github/workflows/orchestrate.yaml	Generated. Builds and deploys to staging on every trunk commit.
.github/workflows/promote.yaml	Generated. Promotes staging to prod and publishes the release.
.github/workflows/external-update.yaml	Generated. Absorbs source updates into the shared manifest.
.github/workflows/build-app.yaml, deploy-app.yaml	Local callbacks for this repo's own application.
.github/workflows/deploy-artifact-a.yaml, deploy-artifact-b.yaml	Local callbacks tracking each external source.
.github/workflows/scenario-suite.yaml	End-to-end driver that validates the full cross-repo flow.

Getting Started

Prerequisites

• A CASCADE_STATE_TOKEN repository secret with contents: write and actions: write scope (the latter lets the source repos dispatch this repo's External Update workflow).

Triggering Pipelines

Push a change under src/** to start the orchestrate run, build the matrix, call the external sharedlib callback, and deploy to staging. When staging is verified, run Actions -> Promote to publish to prod.

What the Test Driver Validates

.github/workflows/scenario-suite.yaml runs weekly (and on demand) and asserts:

Job	Validates
reset	Manifest state resets cleanly.
merge-and-build	Orchestrate runs, the synchronous external callback to artifact-a fires, staging is populated, and a prerelease is created.
external-update-concurrent	artifact-a and artifact-b dispatch External Update at the same time; both {sha, version} land under state.staging.external.* with no loss.
promote-staging	prod is populated, the release is published, and external source state survives the promote.