Promotion Evidence Checklist

For every promotion, ensure you collect the following artifacts:

• Flux Reconcile Success: flux get kustomizations -n flux-system shows Ready.
• Image Policy Match: flux get image policy shows the intended immutable tag was selected.
• Deployed Digest: Use kubectl to confirm the actual digest running in production matches staging.
• Rollback Commit: Identify the specific Git SHA required to revert the change.

Core Exercises (Required)

1. Verify Image Automation: Run flux get images all -A and identify which tags Flux is currently tracking for your backend service.
2. Analyze a Policy: Look at the ImagePolicy regex in flux/apps/backend/production/image-policy.yaml. Explain how it prevents a develop-* image from accidentally being deployed.
3. Perform a Rollback: Revert the most recent image update commit in your repository and observe how Flux automatically restores the previous version in the cluster.

Challenge Exercise (Optional)

Git-Only Image Promotion: Promote a backend image from develop to production using only Git operations (no kubectl). Verify that Flux reconciles each environment in order and that the image is never rebuilt between stages.

Done When

You have completed this chapter when:

• You can explain the difference between “promotion” and “rebuild.”
• You have successfully verified Flux image automation across all three environments.
• You can demonstrate a GitOps-first rollback using a commit revert.
• You can verify the running image digest using kubectl.

Knowledge Check

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