a simple server/client using dnssd (bonjour) and git-style-binaries

gistfile1.rb

#!/usr/bin/env ruby -rubygems
require 'git-style-binary/command'
require 'dnssd'
require 'set'

TestService = Struct.new(:name, :host, :port, :description) unless defined?(TestService)
TcpType = "_dnssdtest._tcp" unless defined?(TcpType)

GitStyleBinary.primary do
  version "dnssd-test"
  banner <<-eos
  Usage: #{File.basename($0)} (server|client)
  eos
  short_desc "test using dnssd (bonjour)"
  opt :name, "the name of the resource you are announcing", :type => String, :default => "dnssd-test"
  opt :description, "the description of the resource you are announcing", :type => String, :default => "a little bonjour test"

  run do |command|
    case command.argv.first
    when "server"
      def announce(name, port)
        tr = DNSSD::TextRecord.new
        tr['description'] = command[:description]

        DNSSD.register(name, TcpType, 'local', port, tr.encode) do |rr|
          puts "Registered #{name} on port #{port}. Starting service."
        end
      end
      announce command[:name], 9419
      sleep(90)
      puts "I'm tired, goodbye"

    when "client"
      def discover(timeout=5)
        waiting_thread = Thread.current

        dns = DNSSD.browse TcpType do |reply|
          DNSSD.resolve reply.name, reply.type, reply.domain do |resolve_reply|
            service = TestService.new(reply.name,
                                      resolve_reply.target,
                                      resolve_reply.port,
                                      resolve_reply.text_record['description'].to_s)
            begin
              yield service
            rescue Done
              waiting_thread.run
            end
          end
        end
        puts "Gathering for up to #{timeout} seconds..."
        sleep timeout
        dns.stop
      end

      def service_list
        list = Set.new
        discover { |obj| list << obj }
        return list
      end

      def list
        service_list.each do |service|
          puts "=== #{service.name} on #{service.host}:#{service.port} ==="
          puts " found #{service.name}"
          if service.description != '' && service.description !~ /^Unnamed repository/
            puts "   #{service.description}"
          end
          puts
        end
      end

      list

    else
      raise "please specify 'server' or 'client'"
    end
  end
end