flask-sock 0.1.0

WebSocket support for Flask

flask-sock

WebSocket support for Flask (and possibly other WSGI frameworks). What makes this package different than other WebSocket servers is that it does not require a greenlet based server (gevent, eventlet) to work. This server is compatible with Werkzeug (Flask's development web server) and Gunicorn.

Installation

pip install flask-sock

Example

from flask import Flask, render_template
from flask_sock import Sock

app = Flask(__name__)
sock = Sock(app)


@sock.route('/echo')
def echo(ws):
    while True:
        data = ws.receive()
        ws.send(data)

Running

To run an application that uses this package, you need to use a supported web server. At this time the supported servers are:

• Werkzeug (Flask development server)
• Gunicorn

Running with Werkzeug

Werkzeug supports WebSocket routing in version 2, which at this time hasn't been officially released. You can install a supported release candidate with the following command:

pip install "werkzeug>=2.0.0rc3"

To run your application use the normal method that you always use. Both the flask run and app.run() methods of starting the Flask application should work.

Running with Gunicorn

To use this package with Gunicorn you need to keep in mind that each active WebSocket client will use up a worker. The most practical way to run a WebSocket server is to use the --threads option to allocate the number of clients that you need:

gunicorn -b :5000 --threads 100 module:app

It is also okay to use multiple workers, each with a number of allocated threads:

gunicorn -b :5000 --workers 4 --threads 100 module:app