ECR private repositories should have tag immutability enabled
Description
This control verifies whether tag immutability is enabled on a private ECR repository. It passes when tag immutability is enabled and set to IMMUTABLE.
Amazon ECR Tag Immutability enables users to rely on descriptive tags as a consistent method for tracking and uniquely identifying images. An immutable tag is fixed, meaning each tag points to a unique image. This enhances reliability and scalability because a static tag will always reference the same image upon deployment. When enabled, tag immutability prevents tags from being overwritten, thereby reducing potential security risks.
For guidance on how to set up a repository with immutable tags or modify the image tag mutability settings for an existing repository, refer to the Image Tag Mutability section in the Amazon Elastic Container Registry User Guide.
