elastic beanstalk環境にあるインスタンスのprivate ipをリストで取得する

ruby

env = JSON.parse(`aws elasticbeanstalk describe-environment-resources --environment-name hogehoge`)
instance_ids = env['EnvironmentResources']['Instances'].map {|instance| instance['Id']}
reservations = JSON.parse(`aws ec2 describe-instances --instance-ids #{instance_ids.join(' ')}`)
private_ips = reservations['Reservations'].flat_map{|reservation| reservation['Instances']}.map{|instance| instance['PrivateIpAddress']}