ECS Service Incorrectly Marked as Changed if it has a Placement Strategy

[pnquest]

Terraform Version

v0.9.11

Affected Resource(s)

• aws_ecs_service

Terraform Configuration Files

resource "aws_ecs_service" "service" {
    name = "${var.task_name}${var.environment}"
    cluster = "${var.cluster_id}"
    task_definition = "${module.tsk.task_arn}"
    desired_count = "${var.task_desired_count}"
    iam_role = "${var.task_role_arn}"

    placement_strategy {
        type = "spread"
        field = "host"
    }
}

Expected Behavior

There was no change to the service definition, so terraform plan should have said there were no changes to apply.

Actual Behavior

Terraform thinks the placement_strategy has changed even though it did not. And re-creates the service on every apply. The only workaround I have found for this is removing the placement_strategy

Steps to Reproduce

1. Create an aws_ecs_service with the placement strategy shown in the above code and apply it.
2. Immediately run terraform plan again and it will show the service as changed.
3. You can repeat this infinitely no matter how many times you apply the supposed changes.

References

• issue 11644 in the main Terraform repo states that the issue (or something very similar) was fixed in version 0.8.6, but this is not the case.

[dcloud9]

Similar behaviour in aws_ecs_task_definition. No code change, but TF 0.11.0 and aws-provider 1.3.0 always trigger a (forces new resource) on container_definitions and id.

[bflad]

@dcloud9 I think you might be referencing a different bug that was fixed in terraform-provider-aws 1.3.1: #2339

@pnquest this should be fixed in terraform-provider-aws 0.1.3: #1025

[dcloud9]

Thanks @bflad. Will update to 1.3.1 soon.

[bflad]

Closing as the mentioned bugs should've been addressed previously (please correct me if I'm wrong): #1169 (comment)

Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!