[AWS::ECS::Service] - [BUG] - Drift for Task Definition version with CODE_DEPLOY DeploymentController

[eylon-commit]

Name of the resource

AWS::ECS::Service

Resource Name

No response

Issue Description

There is an issue while using the DeploymentController of type CODE_DEPLOY which update the task definition revision number outside of CloudFormation.

The drift looks like this:
Expected: "TaskDefinition": "arn:aws:ecs:eu-west-1:xxxxxxxxx:task-definition/taskdef-qa-demo:2"
Actual: "TaskDefinition": "arn:aws:ecs:eu-west-1:xxxxxxxxxxxx:task-definition/taskdef-qa-demo:23"

Example code looks like this:
ECSServiceDemo:
Type: AWS::ECS::Service
Properties:
Cluster: !Sub cluster-${environment}-01
DeploymentController:
Type: CODE_DEPLOY
DesiredCount: 1
LaunchType: FARGATE
LoadBalancers:
- TargetGroupArn: !Ref TGDemo01
ContainerName: !Sub dkr-${environment}-demo
ContainerPort: 5022
NetworkConfiguration:
AwsvpcConfiguration:
AssignPublicIp: DISABLED
SecurityGroups:
- !Sub "{{resolve:ssm:/${environment}/security-group/id/sgr-${environment}-demo}}"
Subnets:
- !Sub "{{resolve:ssm:/${environment}/subnet/net-${environment}-app-01}}"
- !Sub "{{resolve:ssm:/${environment}/subnet/net-${environment}-app-02}}"
ServiceName: !Sub svc-${environment}-demo
TaskDefinition: !Ref TaskDefenitionDemo

The task definition was created by CloudFormation in the same stack, however, because the b/g deployment happens by CodeDeploy outside of CloudFormation, CloudFormation is probably not aware of the current revision number and it causes drift.

The Task Definition name in CloudFormation does NOT contain a revision number.

Expected Behavior

Either remove the TaskDefinition property from drift detection while the DeploymentController is of type CODE_DEPLOY, or make sure CloudFormation can update internally the revision number when DeploymentController is of type CODE_DEPLOY.

Observed Behavior

The revision number differs from the revision number configured in the stack, even though it's not specified in the template.

Test Cases

Create a Task Definition and ECS Service with DeploymentController type of CODE_DEPLOY and configure CodePipeline for CI/CD to trigger CodeDeploy, or do it manually.

Other Details

No response