How to create an ECS task in CloudFormation before the CodePipeline is created

Question

I'm trying to define my ECS stack in Cloudformation, including the CI/CD pipeline and ECR repository. However you run into a bit of a conundrum in that:

1. To create an ECS task definition (AWS::ECS::TaskDefinition) you have to first create a populated ECR repository (AWS::ECR::Repository) so that you can specify the Image property.
2. To populate this repository you have to first create the CodePipeline (AWS::CodePipeline::Pipeline) which will run automatically on creation.
3. To create the pipeline you have to first create the ECS task definition / cluster as the pipeline needs to deploy onto it (back to step 1).

The solutions to this I can see are:

• Don't create the ECR repository in Cloudformation & pass it as a parameter to the stacks.
• Define a dummy image in the task definition to deploy the first time and then create the pipeline which will create the real ECR repository and deploy the real image.
• Create the CodeBuild project and ECR repository in a separate stack, trigger the CodeBuild project with a lambda function (I don't think it runs automatically on creation like the pipeline does), create the ECS cluster and then create the pipeline. This seems more complicated than it should be.

Are there any better ways of approaching this problem?

Answer 1

The way I do it is to ECR repository first, but still using CloudFormation. So I have two templates. One for ECR repo. And the second one for the rest. The ECR repo is passed as a parameter to the second template. But you can also export its Uri to be ImportValue in the second step. The Uri is created as follows:

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

You will also need some initial image in the repo for the task definition. This you can automate by having separated CodeBuild project (no need for CodePipeline) for this initial build.