Mongrel2 handlers

mongrel2_config.py

handler = Handler(
  send_spec = "tcp://*:9999",
  send_ident = "7B0A2BF9-0DB2-4FEB-AD90-75C649B859FC",
  recv_spec = "tcp://*:9998",
  recv_ident = ""
)

main = Server(
    uuid="242DABD4-D5BE-4D16-A042-D4985C8095BD",
    access_log="/logs/access.log",
    error_log="/logs/error.log",
    chroot="./",
    default_host="localhost",
    name="test",
    pid_file="/run/mongrel2.pid",
    port=6767,
    hosts = [
        Host(name="localhost", routes={
            "/": handler
        })
    ]
)

servers = [main]

simple_handler.rb

require 'eventmachine'
require 'em-zeromq'
require 'json'
require 'securerandom'

EM.run do





context = EM::ZeroMQ::Context.new(1)

requests = context.socket(ZMQ::PULL)
requests.connect('tcp://127.0.0.1:9999')

responses = context.socket(ZMQ::PUB)
responses.connect('tcp://127.0.0.1:9998')
responses.setsockopt(ZMQ::IDENTITY, SecureRandom.uuid)

requests.on :message do |msg|
  #SERVER_UUID CLIENT_ID PATH N:HEADERS_JSON, N:BODY,
  #7B0A2BF9-0DB2-4FEB-AD90-75C649B859FC 3 / 29:{"Content-Type":"text/plain"}, 13:Hello handler
  uuid, id, path, rest =  msg.copy_out_string.split(' ', 4)

  netstrings = []
  until rest.empty?                           #6:{JSON},15:hello my friend,
    length = rest[/\A\d+/]                    #6       #15
    rest.slice!(0, length.length+1)           #6:      #15:
    netstrings << rest.slice!(0, length.to_i) #{JSON}  #hello my friend
    rest.slice!(0)                            #,       #,
  end

  headers, body = netstrings
  headers = JSON.parse(headers)

  p headers
  p body

  response_body = 'Hello, Mongrel2!'
  response_body = "HTTP/1.1 200 OK\r\nConnection: close\r\nContent-Length: #{response_body.bytesize}\r\n\r\n#{response_body}"
  #Response format: SERVER_UUID N:CLIENT_IDS, BODY
  #7B0A2BF9-0DB2-4FEB-AD90-75C649B859FC 1:3, Hello Mongrel2!
  response = '%s %d:%s, %s' % [uuid, id.size, id, response_body]
  responses.send_msg(response)
end






end#EM.run

sse_handler.rb

require 'eventmachine'
require 'em-zeromq'
require 'json'
require 'securerandom'

EM.run do





context = EM::ZeroMQ::Context.new(1)

requests = context.socket(ZMQ::PULL)
requests.connect('tcp://127.0.0.1:9999')

responses = context.socket(ZMQ::PUB)
responses.connect('tcp://127.0.0.1:9998')
responses.setsockopt(ZMQ::IDENTITY, SecureRandom.uuid)

clients = []

requests.on :message do |msg|
  uuid, id, path, rest =  msg.copy_out_string.split(' ', 4)

  netstrings = []
  until rest.empty?                           #6:{JSON},15:hello my friend,
    length = rest[/\A\d+/]                    #6       #15
    rest.slice!(0, length.length+1)           #6:      #15:
    netstrings << rest.slice!(0, length.to_i) #{JSON}  #hello my friend
    rest.slice!(0)                            #,       #,
  end

  headers, body = netstrings
  headers = JSON.parse(headers)

  #When a client disconnects, a special METHOD header with value JSON is sent by Mongrel2
  #The body is a JSON document with "type":"disconnect"
  if headers['METHOD'] == 'JSON' && JSON.parse(body)['type'] == 'disconnect'
    clients.delete(id) #Remove client's id from list of connected clients
    puts "Client #{id} disconnected (#{clients.size} clients left)"
  else
    clients << id #First contact, add client's id to list of connected clients

    response_headers = {'Content-Type' => 'text/event-stream'} #SSE MIME type
    response_body = "HTTP/1.1 200 OK\r\n#{response_headers.map{|k,v| "#{k}: #{v}" }.join("\r\n")}\r\n\r\n"
    response = '%s %d:%s, %s' % [uuid, id.size, id, response_body]
    responses.send_msg(response)

    puts "Client #{id} connected (currently #{clients.size} clients)"
  end
end

c = 0
EM.add_periodic_timer 1 do
  event = "event: counter\r\ndata: #{c+=1}\r\n\r\n" #SSE event
  ids = clients.join(' ')
  #                                     UUID of server from config             Send to all connected clients
  responses.send_msg('%s %d:%s, %s' % ['7B0A2BF9-0DB2-4FEB-AD90-75C649B859FC', ids.size, ids, event])
end






end#EM.run

websockets_handler.rb

require 'eventmachine'
require 'em-zeromq'
require 'json'
require 'securerandom'
require 'base64'

EM.run do





context = EM::ZeroMQ::Context.new(1)

requests = context.socket(ZMQ::PULL)
requests.connect('tcp://127.0.0.1:9999')

responses = context.socket(ZMQ::PUB)
responses.connect('tcp://127.0.0.1:9998')
responses.setsockopt(ZMQ::IDENTITY, SecureRandom.uuid)

clients = {}
require 'em-websocket'

requests.on :message do |msg|
  uuid, id, path, rest =  msg.copy_out_string.split(' ', 4)

  netstrings = []
  until rest.empty?                           #6:{JSON},15:hello my friend,
    length = rest[/\A\d+/]                    #6       #15
    rest.slice!(0, length.length+1)           #6:      #15:
    netstrings << rest.slice!(0, length.to_i) #{JSON}  #hello my friend
    rest.slice!(0)                            #,       #,
  end

  headers, body = netstrings
  headers = JSON.parse(headers)

  if headers['METHOD'] == 'WEBSOCKET_HANDSHAKE'
    clients[id] = {websocket: EM::WebSocket::Connection.new(id, {})} #One per client
    #Override send_data to use responses ZMQ socket
    (class << clients[id][:websocket];self;end).send(:define_method, :send_data){|d| responses.send_msg('%s %d:%s, %s' % [uuid, id.size, id, d]) }
    headers.delete_if{|k,v| k =~ /\A[A-Z]+\Z/ }#Delete Mongrel2 custom headers
    http = "GET / HTTP/1.1\r\n#{headers.map{|k,v| "#{k}: #{v}" }.join("\r\n")}\r\n\r\n#{body}"
    clients[id][:websocket].receive_data(http)#Pass HTTP on to em-websocket connection instance
  elsif headers['METHOD'] == 'WEBSOCKET'
    data = JSON.parse(body)
    if data['type'] == 'join'
      clients[id][:name] = data['name']
      clients.each{|i,h| h[:websocket].send(JSON.generate(type: 'join', name:clients[id][:name])) }
      puts "#{data['name']} joined"
    elsif data['type'] == 'message'
      clients.each{|i,h| h[:websocket].send(JSON.generate(type: 'message', name:clients[id][:name], message:data['message'])) }
      puts "#{clients[id][:name]} said: #{data['message']}"
    end
  else
    puts "Received HTTP request"
    response_body = "HTTP/1.1 418 I'm a teapot\r\nContent-Length: 0\r\nConnection: close\r\n\r\nNot really, I'm a WebSocket"
    responses.send_msg('%s %d:%s, %s' % [uuid, id.size, id, response_body])
  end
end






end#EM.run