Broadcast TCP traffic. Spike

duplex.rb

require 'celluloid/io'

module Duplex
  class Server
    include Celluloid::IO
    finalizer :finalize

    def initialize(name, host, port)
      @name = name
      puts "[#{name}] *** Starting server on #{host}:#{port}"
      @server = TCPServer.new(host, port)
      async.run
    end

    def finalize
      @server.close if @server
    end

    def run
      loop { async.handle_connection @server.accept }
    end

    def handle_connection(socket)
      _, port, host = socket.peeraddr
      puts "[#{name}] *** Received connection from #{host}:#{port}"
      reply(socket)
    rescue EOFError
      puts "[#{name}] *** #{host}:#{port} disconnected"
      socket.close
    end

    private
    attr_reader :name
  end

  class Proxy < Server
    def initialize(host, port, *subscribers)
      @subscribers = subscribers
      super("PROXY", host, port)
    end

    def reply(socket)
      sockets = subscribers.map { |subscriber|
        host, port = subscriber
        TCPSocket.new(host, port)
      }
      loop do
        content = socket.readpartial(4096)
        sockets.each do |subscriber|
          subscriber.write(content)
        end
      end
    end

    private
    attr_reader :subscribers
  end

  class Backend < Server
    def reply(socket)
      puts "[#{name}] RECEIVED:"
      loop { puts socket.readpartial(4096) }
    end
  end
end

production = Duplex::Backend.supervise(:PRODUCTION, "127.0.0.1", 1234)

test = Duplex::Backend.supervise(:TEST, "127.0.0.1", 1235)

proxy = Duplex::Proxy.supervise("127.0.0.1", 2000,
                                   ["127.0.0.1", 1234],
                                   ["127.0.0.1", 1235])

trap("INT") { production.terminate; exit }
trap("INT") { test.terminate; exit }
trap("INT") { proxy.terminate; exit }

sleep

To test: curl http://127.0.0.1:2000/hey

To make it extra awesome, you could create a supervision group for each one so it creates a pool using all the cores on the machine :) - eat that, node!

Hehe "production" and "test" here are just stubs though. In the real world, only Duplex::Proxy would exist -- that's why it takes host and port directly, because it would broadcast to other machines. I have some other features planned!! I should write them in a Readme and push it soon.

@txus once you have something more solid, post to the ML.
I'd like to see where this heads and what we can change in celluloid to make this more of a contained unit.

The reverse path is missing, though I guess this is a PoC.