Add an ECR lifecycle policy expiring images with the matching tag after 15 days

Why the Answer Is Correct

The requirement is to store container images and automatically delete those carrying a specific tag once they exceed fifteen days of age. Amazon Elastic Container Registry is the repository service for container images, and ECR lifecycle policies are designed precisely for automated image retention management: a policy rule can select images by tag pattern, which includes matching a specific tag value or selecting untagged images, and can set an expiration expressed in days after which the matching images are expired automatically (A). Because the policy is evaluated and enforced by the service itself, no scheduled job, script, or additional infrastructure is required, which satisfies the most-operational-efficiency requirement. Srikantha enumerated exactly these capabilities, matching images by tag including specific values and specifying age conditions. A is the correct answer.

Why the Other Options Are Wrong

B creates a repository in AWS CodeArtifact and adds a repository policy to expire old assets with the matching tag after fifteen days. CodeArtifact is a repository for software packages and dependencies such as npm, Maven, NuGet, and PyPI packages; it has no concept of container images, image tags, or image layers, so the objects described cannot be stored or expired there. C creates a bucket in Amazon S3 and adds a bucket lifecycle policy to expire objects with the matching tag. An S3 lifecycle rule can expire objects by prefix or object tags, but the container images are held in ECR as managed image versions, and copying them into S3 to expire them would create unmanaged duplicates outside the registry while providing no benefit. D creates an EC2 Image Builder container recipe and adds a build component to expire the container with the matching tag after fifteen days. EC2 Image Builder is a service for building, distributing, and updating images; it provides no capability to expire or delete existing images based on tag and age, and a build component customizes the build rather than performing retention management. A is correct.

Community Comment Notes

Community voted A unanimously. Srikantha explained that ECR supports lifecycle policies that automatically manage container image retention, matching images by tags including specific values or untagged, and specifying age conditions for expiration. matt200 selected A and described the repository plus lifecycle policy approach directly. uncledana noted that the requirement is to automatically manage container images based on a specific tag and age, and that ECR lifecycle policies are specifically designed for that. No alternative received support.