Overview

gevent-websocket

gevent-websocket is a websocket library for the gevent networking library written written and maintained by Jeffrey Gelens It is licensed under the BSD license.

from geventwebsocket.server import WebSocketServer, WebSocketApplication

class EchoApplication(WebSocketServer):
    def on_message(self, message):
        self.ws.send(message)

WebSocketServer(
    ('', 8000),
    Resource({'/': EchoApplication})
)

Installation

Install Python 2.5 or newer and Gevent and its dependencies. The latest release can be download from PyPi or by cloning the repository and running:

$ python setup.py install

The easiest way to install gevent-websocket is directly from PyPi using pip or setuptools by running the commands below:

$ pip install gevent-websocket

or:

$ easy_install gevent-websocket

This also installs the dependencies automatically.

Usage

Gevent Server

At the moment gevent-websocket has one handler based on the Pywsgi gevent Hook up the WebSocketHandler to the Pywsgi Server by setting the handler_class when creating the server instance.

from gevent import pywsgi
from geventwebsocket.handler import WebSocketHandler

server = pywsgi.WSGIServer(("", 8000), websocket_app,
    handler_class=WebSocketHandler)
server.serve_forever()

The handler enhances your WSGI app with a Websocket environment variable when the browser requests a Websocket connection.

def websocket_app(environ, start_response):
    if environ["PATH_INFO"] == '/echo':
        ws = environ["wsgi.websocket"]
        message = ws.receive()
        ws.send(message)

Gunicorn Server

Using Gunicorn it is even more easy to start a server. Only the websocket_app from the previous example is required to start the server. Start Gunicorn using the following command and worker class to enable Websocket funtionality for the application.

gunicorn -k "geventwebsocket.gunicorn.workers.GeventWebSocketWorker" wsgi:websocket_app