update_ecs_agent

function update_ecs_agent () {
  local cluster_name=$1
  local container_arns
  local container_arn
  # Get container instances
  container_arns=$(aws --output json \
    ecs list-container-instances \
    --cluster "${cluster_name}" | \
    jq '.containerInstanceArns[]' | tr -d '"' | tr "\n" " ")
  for container_arn in ${container_arns}; do
    echo "Update ${container_arn}"
    aws ecs update-container-agent \
      --cluster "${cluster_name}" --container-instance "${container_arn}" >/dev/null
  done
}