WebSockets support

[tarcieri]

The previous Rack adapter for Reel supported WebSockets through the reel.websocket environment variable.

Should reel-rack support WebSockets? Is a Rack environment variable the way to go? Or should there be a more direct API, possibly one that can bypass all of Rack's abstraction layers and just hand your program a WebSocket independently of Rack?

I think it'd be neat if reel-rack had a more direct WebSockets API. Maybe we can figure out one that becomes a standard for all Rack web servers support.

[collin]

I'm interested in the answer to this question.

I feel like it's nice if the API could hook into the middleware stack. If I have things like authentication, or some sort of header checking etc. it would be nice to be able to just slot a websocket request in there.

Feels like maybe Rack needs to have a notion of a 'connection' handler. The http1.x handler could roughly be thought of as

def handler(request)
  [status, headers, body] = middleware.first.call(request)
end

An http 'connection' handler might look like...

def handler(connection)
  request = HTTPRequest.new(connection)
  [status, headers, body] = middleware.first.call(request)
  deliver_response status, headers, body
end

A websocket 'connection' handler would maybe look a bit more like...

def handler(connection)
  socket = WebSocketRequest.new(connection)
  [status, headers, body] = websocket_middleware.first.call(request)
  if status > 299
    deliver_response status, headers, body
 else
    socket.accept
 end
end

The WebSocketRequest class or subclass could be responsible for dealing with messages

Could allow for a new top-level configuration block in .ru files, something like..

protocol 'http' do
  use AuthenticationMiddlware
end

protocol 'websocket' do
  use AuthenticationMiddlware
end

After trying that I wanted to type out...

protocol 'websocket' do
  handshake do
    use AuthenticationMiddleware
  end

  map '/git' do
    run WebsocketGitPackUploadHandler
  end

  map '/documents' do
    use StreamingJSONParser
    use StreamingXMLParser
    use StreamingYAMLParser
    run DocumentAPI
  end
end

Could very well be 3am nonsense, but I would like to see Rack figure out websockets.

[ioquatix]

+1 any progress on this?

[ioquatix]

What would be wrong with doing something like this? https://github.com/faye/faye-websocket-ruby

App = lambda do |env|
  if Faye::WebSocket.websocket?(env)
    ws = Faye::WebSocket.new(env)

    ws.on :message do |event|
      ws.send(event.data)
    end

    ws.on :close do |event|
      p [:close, event.code, event.reason]
      ws = nil
    end

    # Return async Rack response
    ws.rack_response

  else
    # Normal HTTP request
    [200, {'Content-Type' => 'text/plain'}, ['Hello']]
  end
end

[ioquatix]

Then, kill this line and pass it along like usual:

reel-rack/lib/reel/rack/server.rb

Line 27 in 5c58e3c

request.respond :bad_request, "WebSockets not supported"

Obviously, we'd want to use the WebSocket support you've developed in conjunction with Celluloid rather than Faye (which I believe uses EventMachine).

[tarcieri]

There's a PR into Reel to use the websocket-driver from Faye