Use PutLifeCyclePolicy with an AWS SDK or CLI

To create a lifecycle policy

The following put-lifecycle-policy example creates a lifecycle policy for the specified repository in the default registry for an account.

aws ecr put-lifecycle-policy \
    --repository-name "project-a/amazon-ecs-sample" \
    --lifecycle-policy-text "file://policy.json"

Contents of policy.json:

{
   "rules": [
       {
           "rulePriority": 1,
           "description": "Expire images older than 14 days",
           "selection": {
               "tagStatus": "untagged",
               "countType": "sinceImagePushed",
               "countUnit": "days",
               "countNumber": 14
           },
           "action": {
               "type": "expire"
           }
       }
   ]
}

Output:

{
   "registryId": "<aws_account_id>",
   "repositoryName": "project-a/amazon-ecs-sample",
   "lifecyclePolicyText": "{\"rules\":[{\"rulePriority\":1,\"description\":\"Expire images older than 14 days\",\"selection\":{\"tagStatus\":\"untagged\",\"countType\":\"sinceImagePushed\",\"countUnit\":\"days\",\"countNumber\":14},\"action\":{\"type\":\"expire\"}}]}"
}

For more information, see Lifecycle Policies in the Amazon ECR User Guide.

class ECRWrapper:
    def __init__(self, ecr_client: client):
        self.ecr_client = ecr_client

    @classmethod
    def from_client(cls) -> "ECRWrapper":
        """
        Creates a ECRWrapper instance with a default Amazon ECR client.

        :return: An instance of ECRWrapper initialized with the default Amazon ECR client.
        """
        ecr_client = boto3.client("ecr")
        return cls(ecr_client)


    def put_lifecycle_policy(self, repository_name: str, lifecycle_policy_text: str):
        """
        Puts a lifecycle policy for an ECR repository.

        :param repository_name: The name of the repository to put the lifecycle policy for.
        :param lifecycle_policy_text: The lifecycle policy text to put.
        """
        try:
            self.ecr_client.put_lifecycle_policy(
                repositoryName=repository_name,
                lifecyclePolicyText=lifecycle_policy_text,
            )
            print(f"Put lifecycle policy for repository {repository_name}.")
        except ClientError as err:
            logger.error(
                "Couldn't put lifecycle policy for repository %s. Here's why %s",
                repository_name,
                err.response["Error"]["Message"],
            )
            raise

Example that puts an expiration date policy.

    def put_expiration_policy(self):
        """
        Puts an expiration policy on the ECR repository.
        """
        policy_json = {
            "rules": [
                {
                    "rulePriority": 1,
                    "description": "Expire images older than 14 days",
                    "selection": {
                        "tagStatus": "any",
                        "countType": "sinceImagePushed",
                        "countUnit": "days",
                        "countNumber": 14,
                    },
                    "action": {"type": "expire"},
                }
            ]
        }

        self.ecr_wrapper.put_lifecycle_policy(
            self.repository_name, json.dumps(policy_json)
        )