atelier/domains/devops/ci-cd.md

CI/CD — Derived Rules

Derives from domains/devops/first-principles.md P2 (Automation), P4 (Rollback First), P5 (Progressive Delivery).

The Pipeline is the Process (P2)

• If it is not in the pipeline, it does not happen. Manual deploys are a bug.
• The pipeline: lint → test → build → deploy → verify.
• Every step is scripted, versioned, and reproducible. No "run this command on the server."

Lint (P2, core C2 Clarity)

• Run the linter on every commit. Fail the build on lint errors.
• Format check (prettier, gofmt, rustfmt). Format is not a debate; it is automated.
• Security lint (eslint-plugin-security, bandit, gosec). Catch the obvious ones.

Test (P2, domains/testing)

• Unit tests in the pipeline. Fast. Every commit.
• Integration tests on merge to main. Slower. Every merge.
• E2E tests before deploy. Slowest. Every deploy candidate.

Build (P7 Immutability)

• Build once. The artifact is immutable. The same artifact goes to every environment.
• The build is reproducible: same commit → same artifact (modulo timestamps, which are stripped).
• Build artifacts are signed and stored. A deploy is a reference to an artifact, not a rebuild.

Deploy (P4 Rollback First, P5 Progressive Delivery)

• Every deploy has a rollback. The rollback is tested before the deploy.
• Progressive: canary (1% → 10% → 100%), blue-green, or feature flags.
• No big-bang deploys. A big-bang deploy is a rollback with no rehearsal.

Verify (P3 Observability)

• After deploy, verify: health checks, smoke tests, metric watching.
• A deploy is not "done" when the code is on the server. It is done when the metrics are healthy.
• Auto-rollback on metric regression. The pipeline watches; humans sleep.

What Violates CI/CD Discipline

Violation	Principle
Manual deploy script	P2 Automation
No rollback path	P4 Rollback First
Big-bang deploy to prod	P5 Progressive Delivery
Rebuild per environment	P7 Immutability
Deploy without health check	P3 Observability
No lint in CI	P2, C2