aws_ecs: TaskDefinition constraint.type 'distinctInstance' is not supported

[IllarionovDimitri]

Describe the bug

According to the documentation ecs.Ec2Taskdefinition supports placement_constraints attribute (which looks kinda redundant, because ecs.Ec2Service supports both placement_constraints and placement_strategies)

ecs.Ec2TaskDefinition(
  self,
  id",
  family="ecs-family",
  task_role=task_role,
  placement_constraints=[ecs.PlacementConstraint.distinct_instances()],
)

Stack deployment raises following exception

Resource handler returned message: "Invalid request provided: Create TaskDefinition: constraint.type 'distinctInstance' is not supported. (Service: AmazonECS; Status Code: 400; Error Code: ClientException; Request ID: 71214110-96ed-4631-a83e-74a3
8206a8db; Proxy: null)" (RequestToken: 59dedc0b-cb70-0b09-c0f5-9b580c5fe3da, HandlerErrorCode: InvalidRequest)

Expected Behavior

Either the ecs.Ec2Taskdefinition can be properly deployed with set placement_constraints attribute or it can be only defined in ecs.Ec2Service (regarding redundancy I am no quite sure, probably there are cases where definition of placement_constraints in ecs.Ec2Taskdefinition also makes sense)

Current Behavior

Error during stack deployment if placement_constraints is defined in ecs.Ec2Taskdefinition

Reproduction Steps

Define placement_constraints as follows in ecs.Ec2Taskdefinition and deploy the esc stack ()there is no error with cdk synth or cdk ls)

ecs.Ec2TaskDefinition(
  self,
  id",
  family="ecs-family",
  task_role=task_role,
  placement_constraints=[ecs.PlacementConstraint.distinct_instances()],
)

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.83.0

Framework Version

No response

Node.js Version

18

OS

Ubuntu 20.04.5 LTS

Language

Python

Language Version

3.10.6

Other information

No response

[peterwoodworth]

It looks like we should clarify this in the docs. You can specify distinctInstances when creating a Service, or running a task. You can specify memberOf when doing the previous two actions, or when creating a task or new revision. See the docs here

In CloudFormation this is reflected in being only able to specify memberOf for TaskDefinition, and being able to specify both for Service. This is also reflected in the API model as having different types for TaskDefinitionPlacementConstraint and PlacementConstraint.

[IllarionovDimitri]

understood.

at least in docs for Python CDK both Ec2Service and Ec2TaskDefinition implement the placement_constraints as (Optional[Sequence[[PlacementConstraint]]), so there is no TaskDefinitionPlacementConstraint, only the PlacementConstrain, which implements both distinct_instances() and member_of() class methods

[peterwoodworth]

Sorry I wasn't clear, we don't separate these in our API, I was describing how they are separated in both CloudFormation and the actual ECS API. I don't think we need to separate these on our end, but we should put in the docstring and make a check at synth time that there are some invalid configurations.

[github-actions]

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