{ 
   "Version":"2012-10-17",
   "Statement":[ 
      { 
         "Effect":"Allow",
         "Principal":{ 
            "AWS":[ 
               "arn:aws:iam::<AWS account>:role/<cluster_operator_role>"
            ],
            "Service":"ec2.amazonaws.com"
         },
         "Action":"sts:AssumeRole"
      }
   ]
}