rubywebsocketcelluloid

Ruby: Connect to remote WebSocket


I'm trying to connect to remote websocket using Celluloid and Websocket client based on celluloid (gem 'celluloid-websocket-client'). The main advantage of this client for me is that I can use callbacks in the form of class methods instead of blocks.

require 'celluloid/websocket/client'
class WSConnection
  include Celluloid

  def initialize(url)
    @ws_client = Celluloid::WebSocket::Client.new url, Celluloid::Actor.current
  end

  # When WebSocket is opened, register callbacks
  def on_open
    puts "Websocket connection opened"
  end

  # When raw WebSocket message is received
  def on_message(msg)
    puts "Received message: #{msg}"
  end

  # When WebSocket is closed
  def on_close(code, reason)
    puts "WebSocket connection closed: #{code.inspect}, #{reason.inspect}"
  end

end

m = WSConnection.new('wss://foo.bar')

while true; sleep; end

The expected output is

"Websocket connection opened"

However, I don't get any output at all. What could be the problem?

I am using

gem 'celluloid-websocket-client', '0.0.2'
rails 4.2.1
ruby 2.1.3

Solution

  • As you noticed in the comments, the gem had no SSL support. That is the trouble. To expound on the answer, here is a resolution, and also some next steps of what to expect for the future:


    [ now ] Override methods in Celluloid::WebSocket::Client::Connection

    This is an example injection to provide SSL support to the current gem. Mine is actually highly modified, but this shows you the basic solution:

    def initialize(url, handler=nil)
      @url = url
      @handler = handler || Celluloid::Actor.current
      #de If you want an auto-start:
      start
    end
    
    def start
      uri = URI.parse(@url)
      port = uri.port || (uri.scheme == "ws" ? 80 : 443)
      @socket.close rescue nil
      @socket = Celluloid::IO::TCPSocket.new(uri.host, port)
      @socket = Celluloid::IO::SSLSocket.new(@socket) if port == 443
      @socket.connect
      @client = ::WebSocket::Driver.client(self)
      async.run
    end
    

    The above sends ripple effects through the other methods however, for example, @handler is used to hold the calling actor, which also has the emitter methods on it. Like I said, my version is very different from the stock gem because I got fed up with it and reworked mine. But then:


    [ soon ] Use Reel::IO::Client and avoid near certain brain damage.

    There are exciting things going on with WebSocket support, and a gem is coming to refactor both server and client implementations of websockets. No more monkeypatches required!

    All websocket functionality is being extracted from Reel and being combined with a websocket-driver abstraction, as Reel::IO... in both ::Server and ::Client varieties.

    Interestingly, this is prompted by Rails which is moving away from EventMachine to Celluloid::IO for websockets:

    A prealpha is online for preview: https://github.com/celluloid/reel-io