Google Cloud Professional Cloud DevOps Engineer — Question 138

You are investigating issues in your production application that runs on Google Kubernetes Engine (GKE). You determined that the source of the issue is a recently updated container image, although the exact change in code was not identified. The deployment is currently pointing to the latest tag. You need to update your cluster to run a version of the container that functions as intended. What should you do?

Answer options

• A. Create a new tag called stable that points to the previously working container, and change the deployment to point to the new tag.
• B. Alter the deployment to point to the sha256 digest of the previously working container.
• C. Build a new container from a previous Git tag, and do a rolling update on the deployment to the new container.
• D. Apply the latest tag to the previous container image, and do a rolling update on the deployment.

Correct answer: B

Explanation

The correct answer is B because using the sha256 digest ensures that you are precisely referencing the previous version of the container that was confirmed to work, eliminating any ambiguity with tags. Option A creates a new tag, which may not guarantee the integrity of the container used. Option C involves building a new container, which may introduce further changes, and option D does not revert to a known stable state but rather reuses the latest tag, which could still have issues.