AWS AutoScaling group のインスタンス一覧を ruby で取得する

require 'aws-sdk-v1'

AWS::config(
  access_key_id: 'xxxxxxxxxxxxxxxxxxx',
  secret_access_key: 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
  region: 'ap-northeast-1',
)

auto_scaling = AWS::AutoScaling.new

instance_ids = auto_scaling.groups['staging_web'].auto_scaling_instances.map(&:instance_id).to_a

response = AWS::EC2::Client.new.describe_instances instance_ids:instance_ids
for reservation in response[:reservation_set]
  for instance in reservation[:instances_set]
    puts instance[:dns_name]
  end
end