Get AWS ECS service instance IPs

get_ecs_service_instance_ips.sh

function get_ecs_service_instance_ips () {
  local cluster_name=$1
  local service_name=$2
  local tasks
  local container_arns
  local ec2_instance_ids

  # Get tasks
  tasks=$(aws --output json \
    ecs list-tasks \
    --cluster "${cluster_name}" \
    --service-name "${service_name}" | \
    jq '.taskArns[]' | sed 's@.*task/@@' | tr -d '"' | tr "\n" " ")

  # Get container arns
  container_arns=$(aws --output json \
    ecs describe-tasks \
    --cluster "${cluster_name}" \
    --tasks ${tasks} | \
    jq '.tasks[].containerInstanceArn' | tr -d '"' | tr "\n" " ")

  # Get EC2 instance ids
  ec2_instance_ids=$(aws --output json \
    ecs describe-container-instances \
    --cluster "${cluster_name}" \
    --container-instances ${container_arns} | \
    jq '.containerInstances[].ec2InstanceId' | tr -d '"' | tr "\n" " ")

  # Get EC2 instance ips
  ec2_instance_private_ips=$(aws --output json \
    ec2 describe-instances \
    --instance-ids ${ec2_instance_ids} | \
    jq '.Reservations[].Instances[].PrivateIpAddress' | tr -d '"')

  echo "Cluster: ${cluster_name}"
  echo "Service: ${service_name}"
  echo "ec2_instance_ids: ${ec2_instance_ids}"
  echo "ec2_instance_private_ips:"
  echo "${ec2_instance_private_ips}"
}