High-performance WebSockets for your Flask apps powered by uWSGI. Low-level uWSGI WebSocket API access and flexible high-level abstractions for building complex WebSocket applications with Flask. Supports several different concurrency models including Gevent. Inspired by Flask-Sockets.
from flask import Flask
from flask.ext.uwsgi_websocket import GeventWebSocket
app = Flask(__name__)
ws = GeventWebSocket(app)
@ws.route('/echo')
def echo(ws):
while True:
msg = ws.receive()
ws.send(msg)
if __name__ == '__main__':
app.run(gevent=100)
Preferred method of installation is via pip:
$ pip install Flask-uWSGI-WebSocket
You can use uWSGI's built-in HTTP router to get up and running quickly:
$ uwsgi --master --http :8080 --http-websockets --wsgi echo:app
...which is what app.run
does after wrapping your Flask app:
app.run(debug=True, host='localhost', port=8080, master=true, processes=8)
uWSGI supports several concurrency models, in particular it has nice support for Gevent. If you want to use Gevent, import flask.ext.uwsgi_websocket.GeventWebSocket
and configure uWSGI to use the gevent loop engine:
$ uwsgi --master --http :8080 --http-websockets --gevent 100 --wsgi echo:app
...or:
app.run(debug=True, gevent=100)
Note that you cannot use multiple threads with gevent loop engine.
For production you'll probably want to run uWSGI behind Haproxy or nginx, instead of using the built-int HTTP router. Explore the uWSGI documentation for more detail about the various concurrency and deployment options.
It's possible to take advantage of Flask's interactive debugger by installing werkzeug's DebuggedApplication
middleware:
from werkzeug.debug import DebuggedApplication
app.wsgi_app = DebuggedApplication(app.wsgi_app, True)
...and running uWSGI with only a single worker:
$ uwsgi --master --http :8080 --http-websockets --wsgi-file --workers 1 --threads 8 app.py
If you use app.run(debug=True)
or export FLASK_UWSGI_DEBUG
, Flask-uWSGI-Websocket will do this automatically for you.
There are several examples available here.
Applies WebSocketMiddleware
to your Flask App, allowing you to decorate routes with the route
method, turning them into WebSocket handlers.
Additionally monkey-patches app.run
, to run your app directly in uWSGI.
route(url)
run(debug, host, port, **kwargs)
**kwargs
are passed to uWSGI as command line arguments.
WebSocket Middleware which automatically performs WebSocket handshake and passes WebSocketClient
instances to your route.
Exposes the uWSGI WebSocket API.
recv()
(alias WebSocket.receive()
)
recv_nb()
send(msg)
send_binary(msg)
recv_nb()
send_from_sharedarea(id, pos)
send_binary_from_sharedarea(id, pos)
Fancier WebSocket abstraction that takes advantage of Gevent loop engine. Requires uWSGI to be run with --uwsgi
option.
Automatically performs WebSocket handshake and passes a GeventWebSocketClient
instance to your route.
WebSocket client abstraction with fully non-blocking methods.
receive()
send(msg)
close()
connected
Normally websocket routes happen outside of the normal request context. You can get a request context in your websocket handler by using app.request_context
:
app = Flask(__name__)
ws = GeventWebSocket(app)
@ws.route('/websocket')
def websocket(ws):
with app.request_context(ws.environ):
print request.args