Using custom-named ECS / Fargate services: CloudFormation cannot update a stack when a custom-named resource requires replacing

❓ General Issue

Hi! I think we need some advice how the AWS CDK is meant to be used when generating Fargate services. Lately, after CDK updates we have been seen a lot of following errors:

CloudFormation cannot update a stack when a custom-named resource requires replacing. Rename cluster-name\app-name and update the stack again.
--
  | Physical ID:arn:aws:ecs:eu-central-1:account-id:service/cluster-name/app-name

So far, we have manually named all of our services with simplified names. For example, the mentioned app-name.

If we use CDK generated names we see env-name-app-nameService70147683-W8VL0MQANBBH.

new ecs.FargateService(stack, `${prefix}-${service.name}`, {
      cluster,
      taskDefinition,
      // uncomment to fix the name
      // serviceName: service.name,
      desiredCount: service.desiredCount,
      enableECSManagedTags: true,
      propagateTags: ecs.PropagatedTagSource.SERVICE,
    })

The problem comes from our deployment pipeline which uses fixed names for services since the service name is the only proper identifier provided by AWS in this case:

# Repeat for each service and environment
      - Name: UpdateDev
        Actions:
        - Name: DeployImage
          InputArtifacts:
            - Name: BuildOutput
          ActionTypeId: {Category: Deploy, Owner: AWS, Version: 1, Provider: ECS}
          RoleArn: !Sub arn:aws:iam::${AccountNumber}:role/deploy-role
          Configuration:
            ClusterName: !Sub cluster-name
            ServiceName: !Ref ServiceName
            FileName: imagedefinitions.json

It seems difficult to me to find a workaround for this issue since the service names for CodePipeline deployment are not known (?) before the stacks have been initialized or deployed. We have one account for deployment tools and separate accounts for testing and production environments.

The Question

What would be the “official” way to proceed without fixed names and still be able to use the CDK generated service names in deployment pipeline which is deployed in different account before any other stacks are deployed?

Environment

• CDK CLI Version: 1.10.0
• Module Version: 1.10.0
• OS: MacOS
• Language: TypeScript

[piradeepk]

@markusl, this is because CloudFormation attempts to bring up the new version of your ECS/Fargate service prior to deleting the old service (this only happens on replacement). If the new service creation fails, your old service will be used to rollback.

Since you’re using a custom named resource, it is unable to create the new service with the same resource names (due to collisions). Would it make sense to have a version/revision/unique identifier appended to the end of your resource name?

[markusl]

Let’s close the issue if there is nothing CDK team can do to help the situation.