Core Exercises (Required)

1. Test Local Hooks: Try to commit a dummy file named kubeconfig.yaml and observe the block-secrets hook in action.
2. PR Validation: Open a pull request with an intentional YAML syntax error in a Flux manifest. Identify which CI job catches the error first.
3. Review AI Output: Analyze a CodeRabbit review comment on one of your PRs. Identify at least one pattern or “KISS” principle violation it flagged.
4. Concurrency Test: Manually trigger two overlapping workflow runs for the same environment. Verify that the concurrency group correctly manages their execution.

Challenge Exercise (Optional)

Hook Bypass Detection Trace: Deliberately bypass all local hooks using --no-verify, push to a feature branch, and document which CI layer catches the violation first. Trace the full detection path from push to pipeline failure.

Done When

You have completed this chapter when:

• You can explain the “Layered Defense” model and why each layer is necessary.
• You have successfully installed and triggered pre-commit hooks locally.
• You can trace the path of a change from workstation to cluster apply.
• You understand how to verify and approve a Terraform plan within GitHub Actions.
• You can describe the role of CodeRabbit in the automated review process.

Knowledge Check

Before finishing this chapter, complete the Quiz to verify your understanding of the guardrail principles.