Nginx and Flask-socketio Websockets: Live, but Not Messaging?

Question

I'm having trouble getting Nginx to play well with the Python Flask-socketio library (which is based on gevent). Currently, as we are actively developing, I am trying to get Nginx to work only as a proxy. To send pages, I can make this work, either by directly launching the flash socket application, or by skipping the guns. One delay: messaging with websites doesn't seem to work. Pages are successfully posted and displayed. However, when I try to use websockets, they do not work. They are alive enough that websocket believes that it is connected, but they will not send a message. If I remove the Nginx proxy, they will work. Firefox gives me this error when I try to send a message:

Firefox cannot establish a connection to the server at ws: ///socket.io/1/websocket/.

If the web address is where the server is located, and the unique identifier is just a bunch of random numbers. It seems that it is doing enough to maintain a live connection (for example, the client believes that it is connected), but cannot send a message through the website. I should think that the problem is related to some part of the proxy server, but I have serious debugging problems, which can be a problem (partly because this is my first round with Flask-socketIO and nginx). The configuration file that I use for nginx:

user       <user name>;  ## This is set to the user name for the remote SSH session
worker_processes  5;

events {
  worker_connections  1024;  ## Default: 1024
}

http {
  default_type application/octet-stream;
  log_format   main '$remote_addr - $remote_user [$time_local]  $status '
    '"$request" $body_bytes_sent "$http_referer" '
    '"$http_user_agent" "$http_x_forwarded_for"';
  sendfile     on;
  server_names_hash_bucket_size 128; # this seems to be required for some vhosts

  server {
    listen 80;
    server_name _;
    location / {
        proxy_pass http://localhost:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
    }
  } 
}

websocket, . , werkzeug Proxy_Fix- Flask app.wsgi_app, wsgi. , . - - , /.

Answer 1

. -, Ubuntu, NginX gevent-socketio. :

• Ubuntu 12.04 - nginx (1.1.19 1.6.x ). ? . , websockets , 1.3.13 , .
• gevent-socketio , /socket.io. HTTP-, , ( , SSL ).
• # 1, nginx apt-get, ... nginx Ubuntu. , , . .conf .

- , :

• nginx "nginx -v". 1.4, .
• nginx.conf. , .
• , IP- nginx.conf.
• , (, socketio.js) .
• . EC2, 80 (HTTP) 443 (SSL/HTTPS).

, .

• nginx Ubuntu (full ref) :

  sudo apt-get install python-software-properties
  sudo apt-get install software-properties-common
  sudo add-apt-repository ppa:nginx/stable
  sudo apt-get update
  sudo apt-get install nginx
  

  , Windows, .

• , nginx 2013 , . nginx, gevent-socketio SSL , ( Nginx, Gevent-socketio, Node.js SSL). nginx 1.6 - ( gevent-socketio) SSL:

  user <user account, probably optional>;
  worker_processes  2;
  error_log  /var/log/nginx/error.log;
  pid        /var/run/nginx.pid;
  
  events {
      worker_connections  1024;
  }
  
  http {
      include mime.types;
      default_type       application/octet-stream;
      access_log         /var/log/nginx/access.log;
      sendfile           on;
  #   tcp_nopush         on;
      keepalive_timeout  3;
  #   tcp_nodelay        on;
  #   gzip               on;
      client_max_body_size 20m;
      index              index.html;
  
      map $http_upgrade $connection_upgrade {
              default upgrade;
              ''      close;
      }
  
      server {
        # Listen on 80 and 443
        listen 80 default;
        listen 443 ssl;  (only needed if you want SSL/HTTPS)
        server_name <your server name here, optional unless you use SSL>;
  
        # SSL Certificate (only needed if you want SSL/HTTPS)
        ssl_certificate <file location for your unified .crt file>;
        ssl_certificate_key <file location for your .key file>;
  
        # Optional: Redirect all non-SSL traffic to SSL. (if you want ONLY SSL/HTTPS)
        # if ($ssl_protocol = "") {
        #   rewrite ^ https://$host$request_uri? permanent;
        # }
  
        # Split off basic traffic to backends
        location / {
          proxy_pass http://localhost:8081; # 127.0.0.1 is preferred, actually.
          proxy_redirect off;
        }
  
        location /socket.io {
          proxy_pass          http://127.0.0.1:8081/socket.io; # 127.0.0.1 is preferred, actually.
          proxy_redirect off;
          proxy_buffering off; # Optional
          proxy_http_version 1.1;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection $connection_upgrade;
        }
      }
   }
  

• , Flask-socketio , . :

  from flask import Flask, render_template, session, request, abort
  import flask.ext.socketio
  FLASK_CORE_APP = Flask(__name__)
  FLASK_CORE_APP.config['SECRET_KEY'] = '12345' # Luggage combination
  SOCKET_IO_CORE = flask.ext.socketio.SocketIO(FLASK_CORE_APP)
  
  @FLASK_CORE_APP.route('/')
  def index():
      return render_template('index.html')
  
  @SOCKET_IO_CORE.on('message')
  def receive_message(message):
      return "Echo: %s"%(message,)
  
  SOCKET_IO_CORE.run(FLASK_CORE_APP, host=127.0.0.1, port=8081)
  

• , socketio.js, . :

  <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.16/socket.io.min.js"></script>
  <script type="text/javascript">
      var url = window.location.protocol + document.domain + ':' + location.port,
          socket = io.connect(url);
      socket.on('message', alert);
      io.emit("message", "Test")
  </script>
  

• superuser, . Amazon EC2 . .

• , . . nginx.