socketry/rubydns

#!/usr/bin/env ruby
require 'rubydns'

INTERFACES = [
    [:udp, '0.0.0.0', 5300],
    [:tcp, '0.0.0.0', 5300]
]

Name = Resolv::DNS::Name
IN = Resolv::DNS::Resource::IN

# Use upstream DNS for name resolution.
UPSTREAM = RubyDNS::Resolver.new([[:udp, '8.8.8.8', 53], [:tcp, '8.8.8.8', 53]])

# Start the RubyDNS server
RubyDNS.run_server(INTERFACES) do
    match(/test.mydomain.org/, IN::A) do |transaction|
            transaction.respond!('10.0.0.80')
    end

    # Default DNS handler
    otherwise do |transaction|
            transaction.passthrough!(UPSTREAM)
     end
end