code: def tag_instances_on_cluster(cluster_name, project='cwc'):
      
      # Get the relevant instance ids from the ecs cluster
      ecs = boto3.client('ecs')
      task_arns = ecs.list_tasks(cluster=cluster_name)['taskArns']
      if not task_arns:
          return
      tasks = ecs.describe_tasks(cluster=cluster_name, tasks=task_arns)['tasks']
      container_instances = ecs.describe_container_instances(
          cluster=cluster_name,
          containerInstances=[task['containerInstanceArn'] for task in tasks]
          )['containerInstances']
      ec2_instance_ids = [ci['ec2InstanceId'] for ci in container_instances]
  
      # Instantiate each instance to tag as a resource and create project tag
      for instance_id in ec2_instance_ids:
          tag_instance(instance_id, project=project)
      return
docs: Adds project tag to untagged instances in a given cluster.
  
      Parameters
      ----------
      cluster_name : str
          The name of the AWS ECS cluster in which running instances
          should be tagged.
      project : str
          The name of the project to tag instances with.