How to fix Error: Error creating ECS Cluster: ClusterContainsServicesException in Terraform

Before attempting deletion, check what services are currently deployed:

aws ecs list-services --cluster <cluster-name> --region <region>
aws ecs describe-services --cluster <cluster-name> --services <service-name> --region <region>

This shows all active services and their status (ACTIVE, DRAINING, INACTIVE).

Delete the ECS services before attempting to delete the cluster. In Terraform, ensure aws_ecs_service resources are defined and will be destroyed first:

resource "aws_ecs_service" "example" {
  name            = "example-service"
  cluster         = aws_ecs_cluster.example.id
  task_definition = aws_ecs_task_definition.example.arn
  desired_count   = 1
}

resource "aws_ecs_cluster" "example" {
  name = "example-cluster"
}

Terraform will automatically destroy services before the cluster due to implicit dependencies.

If you have complex dependencies, add explicit depends_on to ensure proper destruction order:

resource "aws_ecs_cluster" "example" {
  name = "example-cluster"

  depends_on = [
    aws_ecs_service.example
  ]
}

This ensures services and their IAM policies are cleaned up before the cluster.

If services are stuck in DRAINING state, scale down the desired task count:

aws ecs update-service --cluster <cluster-name> --service <service-name> --desired-count 0 --region <region>

Wait for tasks to fully drain before proceeding with cluster deletion.

If using EC2 launch type, deregister all container instances from the cluster:

aws ecs list-container-instances --cluster <cluster-name> --region <region>
aws ecs deregister-container-instance --cluster <cluster-name> --container-instance <instance-arn> --force --region <region>

Remove all capacity provider associations before deletion.

After all services and instances are removed, retry the Terraform destroy:

terraform destroy

If the destroy still hangs, you may need to wait a few minutes for AWS to fully propagate the service deletions (eventual consistency), then run destroy again.