AWS SDK Route53 ruby sample. Register the new record sets. http://docs.aws.amazon.com/AWSRubySDK/latest/frames.html http://docs.aws.amazon.com/Route53/latest/APIReference/API_ChangeResourceRecordSets.html#API_ChangeResourceRecordSets_Examples

r53sample.rb

r53 = AWS::Route53.new(
  :access_key_id => 'aws-key-id',
  :secret_access_key => 'aws-secret-key')

response = r53.client.list_resource_record_sets(
  :hosted_zone_id => "zone-id",
  :start_record_name => 'xxx.example.com', 
  :start_record_type => 'CNAME'
)
puts response[:resource_record_sets].map{|r| r[:name]}

change1 = { 
  :action => 'CREATE',
  :resource_record_set => {
    :name => "sub-domain-name.example.com",
    :type => "CNAME",
    :ttl => 600,
    :resource_records => [{:value => "example.com"}]
}}

change2 = { 
  :action => 'CREATE',
  :resource_record_set => {
    :name => "sub-domain-name.example.com",
    :type => "A",
    :ttl => 600,
    :resource_records => [{:value => "XX.XX.XX.XX"}]
}}

r53.client.change_resource_record_sets({
  :hosted_zone_id => '/hostedzone/XXXXXXXXXXXX',
  :change_batch => {
    :changes => [change1, change2]
  }
})