ecs error: "An error occurred (ClusterNotFoundException) when calling the..."

Question

I've defined a cluster in ECS and failed to clean it up properly. I've terminated EC2 instances that are associated with this cluster which get recreated. No clusters/repos/services appear in my ECS console. In fact, when I go to this service through the console, I see the getting started wizard. I've started some digging with the CLI.

When issuing the commands:

• aws ecs list-container-instances
• aws ecs list-services
• aws ecs list-tasks

I see the message An error occurred (ClusterNotFoundException) when calling the ____ operation: Cluster not found. (even when including my region).

When issuing the command:

• aws ecs describe-clusters

I get the result:

{
    "clusters": [],
    "failures": [
        {
            "arn": "arn:aws:ecs:us-east-1:123456789012:cluster/default",
            "reason": "MISSING"
        }
    ]
}

Any ideas on how I can clean up my mess would be much appreciated. Thanks!

Answer 1

There was a CloudFormation listing this cluster in its configuration. Even though this cluster was not visible in the ECS console, a CloudFormation stack was creating EC2 instances using the deleted cluster configuration. The CloudFormation stack was responsible for these EC2 instances. Deleting the stack solved this issue.