Any Success with Sinatra Working Together with Eventmachine Websockets

Any success with Sinatra working together with EventMachine WebSockets?

Did not try it, but should not be too hard:

require 'em-websocket'
require 'sinatra/base'
require 'thin'

EM.run do
  class App < Sinatra::Base
    # Sinatra code here
  end

  EM::WebSocket.start(:host => '0.0.0.0', :port => 3001) do
    # Websocket code here
  end

  # You could also use Rainbows! instead of Thin.
  # Any EM based Rack handler should do.
  Thin::Server.start App, '0.0.0.0', 3000
end

Also, Cramp has a websocket implementation that works directly with Thin/Rainbows! you might be able to extract, so you won't even need to run the server on another port.

Accessing an EventMachine channel from a Sinatra route

In case others don't know what we're talking about in the comments, here's an example of using a class instance variable in the way I suggested. This runs, but I don't know if it does what's expected:

require 'em-websocket'
require 'sinatra'
require 'haml'

module Example

  def self.em_channel
    @em_channel ||= EM::Channel.new
  end

  EventMachine.run do

    class App < Sinatra::Base
      configure do
        enable :inline_templates
      end

      get '/' do
        haml :index
      end

      get '/test' do
        Example.em_channel.push "Test request hit endpoint"
        status 200
      end
    end


    EventMachine::WebSocket.start :host => '0.0.0.0', :port => 8080 do |socket|
      socket.onopen do
        sid = Example.em_channel.subscribe { |msg| socket.send msg }
        Example.em_channel.push "Subscriber ID #{sid} connected!"

        socket.onmessage do |msg|
          Example.em_channel.push "Subscriber <#{sid}> sent message: #{msg}"
        end

        socket.onclose do
          Example.em_channel.unsubscribe(sid)
        end
      end
    end

    App.run!
  end
end

__END__

@@ layout
%html
  = yield

@@ index
%div.title Hello world.

Use eventmachine with sinatra, why it will always quit?

Just run your Sinatra app under thin server and it will be fired with Eventmachine

padrino && websockets

Maybe you need to install daemons:

Edit your Gemfile:

# Adding this
gem 'daemons'

Install missing gems:

$ bundle install

EventMachine WebSockets - Subscribe ws to EM channels vs Keeping sockets in collection

The EventMachine::Channel class is simply an abstraction that handles the iteration of a subscribers array. If you look at the Ruby source code for EventMachine::Channel#push, you see it is similar to what you propose:

def push(*items)
  items = items.dup
  EM.schedule { @subs.values.each { |s| items.each { |i| s.call i } } }
end

In fact, if you don't need to duplicate your items array, it is actually slower than manually iterating the list. However, I doubt that the performance impact is significant. EventMachine::Channel is simply an abstraction that makes managing lists of clients easier.

EventMachine Web-socket Client TLS Connections

It turns out that currently EventMachine::WebSocketClient does NOT support wss:// connections. The server does, but that is a separate project.

I ended up using faye-websocket-ruby which does support wss://

There are examples in the README.md on how to use.

---

Related Topics