Listing EC2 instances

instances.rb

# using EC2 client
ec2 = Aws::EC2::Client.new
ec2.describe_instances.each_page do |resp|
  resp.reservations.each do |reservation|
    reservation.instances.each do |intsance|
      puts instance.instance_id
    end
  end
end

# using EC2 resource interface
ec2 = Aws::EC2::Resource.new
ec2.instances.each do |instance|
  puts instance.id
end