Query: vpc_subnets_for_ecs_cluster

select
  s.subnet_id as subnet_id
from
  aws_ecs_container_instance as i
  right join
    aws_ec2_instance as c
    on c.instance_id = i.ec2_instance_id
  right join
    aws_vpc_subnet as s
    on s.subnet_id = c.subnet_id
where
  i.cluster_arn = $1;