AWS stack output ECR image name

Question

I'm using cloudformation to create a set of ECR repositories to use in my root script. For the task defintions I need to have the image names of these created repositories in a format like this:

{ACC_NR}.dkr.ecr.eu-central-1.amazonaws.com/{REPO_NAME}

When I output the created ECR in the outputs I only have 2 options. I can either get the {REPO_NAME} without the rest of the information in front of it or I will get the ARN, which contains more or less the same information but structured differently.

What is the best way to get the image name in a variable inside a CF template? Basically I need the string that you would get when nagivating to the ECR and pressing the "copy" button next to the repository.

Answer 1

You can construct the ARN you require "manually". For example, to add it as an output to a stack that creates AWS::ECR::Repository, you could do the following:

Resources:

    MyECRRepo:
        Type: AWS::ECR::Repository
        Properties:
            # some properties

Outputs:

    MyARN:
        Value: !Sub "${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/{MyECRRepo}"