How to use ECS placementConstraints in CloudFormation - amazon-web-services

Question

I am trying to use placementConstraints in my service definition using CloudFormation, but it does not exist as property in the AWS::ECS::Service resource. Is there a workaround?
ECS Service: http://docs.aws.amazon.com/AmazonECS/latest/developerguide/service_definition_paramters.html
CloudFormation ECS Service Resource: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-service.html

Answer 1

PlacementConstraint exists as a property of AWS::ECS::Service at the time of this writing. Quoting from AWS docs:
PlacementConstraint is a property of the AWS::ECS::Service resource
that specifies the placement constraints for the tasks in the service
to associate with an Amazon EC2 Container Service (Amazon ECS)
service.
Ref:
[1] http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ecs-service-placementconstraints-placementconstraint.html
[2] http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-service.html#cfn-ecs-service-placementconstraints

Answer 2

This works for me ! If you using yaml wrong indentation can lead to this error.
ApplicationService:
Type: AWS::ECS::Service
DependsOn:
- ALBListener
- ApplicationTaskDefinition
- ALBTargetGroup
Properties:
Cluster:
'Fn::ImportValue': !Sub ecs-${EnvironmentName}-clustername
DesiredCount: 15
LoadBalancers:
- ContainerName: !Sub ${AWS::StackName}-app
ContainerPort: 8080
TargetGroupArn: !Ref ALBTargetGroup
Role:
'Fn::ImportValue': !Sub ecs-${EnvironmentName}-servicerole-arn
TaskDefinition: !Ref ApplicationTaskDefinition
PlacementConstraints:
- Expression: attribute:ecs.instance-type == t2.medium
Type: memberOf
PlacementStrategies:
- Type: spread
Field: attribute:ecs.availability-zone
If this not working for you please post your cfn file here !