[AWS::ECS::Service] - [BUG] - changing from LaunchType to CapacityProviderStrategy fails through Cloudformation

[allixsenos]

Name of the resource

AWS::ECS::Service

Resource Name

No response

Issue Description

Going from LaunchType to CapacityProviderStrategy on an ECS Service that has a defined ServiceName fails through Cloudformation because it tries to recreate the Service.

The same action can be performed in-place through the AWS ECS web console without any issue.

Recreating the resource is unnecessary and makes it impossible to execute this change through Cloudformation short of doing an unnecessary rename operation.

Expected Behavior

Cloudformation should reconfigure the ECS Service in place and not try to recreate it.

Observed Behavior

Cloudformation tries to recreate the ECS Service which then fails because the name is statically defined.

Test Cases

1. define an ECS Service with a fixed name using FARGATE Launch Type

  Service:
    Type: AWS::ECS::Service
    DependsOn: LoadBalancerRule
    Properties:
      ServiceName: "myservicename"
      Cluster: "default"
      LaunchType: FARGATE
      DeploymentConfiguration:
        MaximumPercent: 200
        MinimumHealthyPercent: 100
      HealthCheckGracePeriodSeconds: 40
      DesiredCount: 2
      EnableExecuteCommand: true
      NetworkConfiguration:
        AwsvpcConfiguration:
          SecurityGroups:
            - !ImportValue 'awesome-vpc:SecurityGroupVeryPermissive'
          Subnets:
            - !ImportValue 'awesome-vpc:SubnetPrivateOne'
            - !ImportValue 'awesome-vpc:SubnetPrivateTwo'
      TaskDefinition: !Ref TaskDefinition
      LoadBalancers:
        - ContainerName: haproxy
          ContainerPort: !Ref HaproxyListenPort
          TargetGroupArn: !Ref TargetGroup
      EnableECSManagedTags: true
      PropagateTags: SERVICE

2. once deployed, remove LaunchType: FARGATE and add

      CapacityProviderStrategy:
        - CapacityProvider: FARGATE_SPOT
          Base: 0
          Weight: 1

Observed error:

Resource handler returned message: "Resource of type 'AWS::ECS::Service' with identifier 'myservice' already exists." (RequestToken: XYZ, HandlerErrorCode: AlreadyExists)

Executing the same change via ECS Console works fine.

Other Details

No response