Can't create ECS deployment group using CloudFormation (loadBalancerInfo error)

Question

I couldn't create ECS deployment group using CloudFormation template and got error message below.
```
For ECS deployment group, loadBalancerInfo must not contain targetGroupInfo list (Service: AmazonCodeDeploy; Status Code: 400; Error Code: InvalidLoadBalancerInfoException; Request ID: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx; Proxy: null)
```
My CFn template fragment is as follows. I commented out "TargetGroupInfoList" in response to the error message, but it didn't work. (got exactly same error message)
```
  # CodeDeploy Deployment groups
  DeploymentGroup:
    Type: AWS::CodeDeploy::DeploymentGroup
    Properties: 
      ApplicationName: !Ref DeployApplication
      DeploymentStyle:
        DeploymentType: BLUE_GREEN
        DeploymentOption: WITH_TRAFFIC_CONTROL
      BlueGreenDeploymentConfiguration:
        DeploymentReadyOption:
          ActionOnTimeout: CONTINUE_DEPLOYMENT
        TerminateBlueInstancesOnDeploymentSuccess:
          Action: TERMINATE
          TerminationWaitTimeInMinutes: 5
      DeploymentConfigName: CodeDeployDefault.OneAtATime
      DeploymentGroupName: myapp-dg
      ECSServices:
        - ClusterName: !Ref ECSCluster
          ServiceName: !GetAtt ECSService.Name
      LoadBalancerInfo:
        ElbInfoList: 
          - Name: !Ref ALB
#        TargetGroupInfoList:
#          - Name: !Ref TargetGroup01
#          - Name: !Ref TargetGroup02
      ServiceRoleArn: arn:aws:iam::xxxxxxxx:role/CodeDeployServiceRole
```
How should I define "LoadBalancerInfo" in the template?

Accepted Answer

I think the problem is you have 2 target groups.
> Adding more than one target group to the array is not supported.

Other issue is with BLUE_GREEN -deployment type being used with ECS 
> AWS CloudFormation supports blue/green deployments on the AWS Lambda compute platform only.

See https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-codedeploy-deploymentgroup-loadbalancerinfo.html

Answer

If you want to simplify this process for yourself you could use CLI tools that will take care of generating the CFN templates for your use-case. I write/maintain/use [ECS Compose-X ](https://labs.compose-x.io/apps/traefik_ecs_part1.html) which allows me to do everything in a docker compose syntax. You also could look at the CDK or Copilot. Note that Blue/Green on ECS is something that is fairly restrictive, you are better off (IMHO) setting up ALB / NLB to the service (with healthcheck) + healthcheck at the container level and let CFN deal with rolling back for you. We work that way all the time and this works like a charm.

Can't create ECS deployment group using CloudFormation (loadBalancerInfo error)

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