Exam Professional Cloud DevOps Engineer topic 1 question 142 discussion

https://cloud.google.com/kubernetes-engine/docs/concepts/about-container-images#disadvantages_of_image_tags Because the code change is not known, it may be possible that the image was updated with same tag and now it's not working, so pointing using the tag won't solve the issue as it will always point to the latest digest sha256 (which is faulty). So we must point the deployment to the sha256 digest of the previously working container.

Using the SHA256 digest ensures that you specifically deploy the exact version of the container that was previously working as intended, regardless of any changes made to the latest tag.

To update your Google Kubernetes Engine (GKE) cluster to run a version of the container that functions as intended, despite the unknown change in the latest container image, the recommended approach is (option B). Alter the deployment to point to the sha256 digest of the previously working container. Using the sha256 digest provides a precise and immutable reference to a specific version of the container image, ensuring that the exact image that was known to work is deployed. This approach eliminates any ambiguity associated with using tags like "latest" and provides a reliable way to rollback to a known-good state. By referencing the sha256 digest, you maintain control over the version of the container image deployed in the cluster and can effectively address issues arising from unanticipated changes in the latest tag.

Vote B

This question looks to tease out the knowledge of tag vs digest while deploying containers. The best approach is to figure out the previously functional digest and apply to deployment. Tag is mutable, using a tag like latest in deployment is confusing and prone to cause deployment inconsistency. https://cloud.google.com/kubernetes-engine/docs/concepts/about-container-images

https://cloud.google.com/kubernetes-engine/docs/concepts/about-container-images

Answer D seems correct. https://cloud.google.com/kubernetes-engine/docs/how-to/updating-apps