Dear Miguel:

Hello

This is from your video streaming page + emit , server side (i removed the Return):

@app.route('/video_feed')
def video_feed():
       socketio.emit('from_flask', Response(gen(), mimetype='multipart/x-mixed-replace; 
                                                boundary=frame'),namespace='/test')

here the problems are Response and the Generator mixing with the event-driven SocketIO

client

 socket.on('from_flask', function (data) { 
          $("#image").attr("src",data) ;
           });

html

<img id="image" src="video_feed">

Would you please help me ? i know something is wrong here but i cant't figure it

Thanks a million for your great work

Hello Miguel, My requirement. I'm building an app for a chatbot. The flask app will receive messages from the front-end via javascript socket-io and query that message to a remote NLP model through API. When I'm running the app with flask run command the api works correctly but when I run it with gunicorn --worker-class eventlet -w 1 module:app the API doesn't work. Since my server isn't showing any errors. Neither it is crashing it just returns the default message which I have written to print if the API isn't run.

Hi Miguel,

I'm encountering with eventlet + redis, after receiving the following error, it won't be able to do an "emit"/"send" events to the future clients anymore

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/local/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/usr/local/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "/home/vf/env/lib/python3.5/site-packages/socketio/pubsub_manager.py", line 143, in _thread
    self._handle_emit(data)
  File "/home/vf/env/lib/python3.5/site-packages/socketio/pubsub_manager.py", line 101, in _handle_emit
    callback=callback)
  File "/home/vf/env/lib/python3.5/site-packages/socketio/base_manager.py", line 103, in emit
    self.server._emit_internal(sid, event, data, namespace, id)
  File "/home/vf/env/lib/python3.5/site-packages/socketio/server.py", line 322, in _emit_internal
    binary=binary))
  File "/home/vf/env/lib/python3.5/site-packages/socketio/server.py", line 333, in _send_packet
    self.eio.send(sid, encoded_packet, binary=False)
  File "/home/vf/env/lib/python3.5/site-packages/engineio/server.py", line 158, in send
    self._get_socket(sid).send(packet.Packet(packet.MESSAGE, data=data,
  File "/home/vf/env/lib/python3.5/site-packages/engineio/server.py", line 344, in _get_socket
    raise KeyError('Session is disconnected')
KeyError: 'Session is disconnected'

Trying to emit from a Celery task in Flask. Not sure if this is possible. Here's my simplified code:

@celery.task()
def do_stuff():
    logger.info('emmittting')
    socketio.emit('my response', {'data': user_cache_key})

I'm using Gunicorn + Celery + SocketIO + Redis (broker + result backend for Celery). Is this even possible? I'm not sure if gevent can communicate to/from a celery worker.

I'm hoping to use websockets to track the progress of long-running Celery tasks.

Hi Miguel,

really awesome project.

I have a problem when use the Flask-SocketIO. I wanna start a background task automatic when the socketio server begins to run. The background task can continuously broadcast the message to client by using emit(). But the socketio.start_background_task() is not a decorator, it seems cannot start the background task with the socketio server starting. Moreover, I have a requirement which is starting some background tasks in right time. Are you planning to become the method start_background_task() to a decorator, and integrate a APScheduler compatibility?

Thanks! Keep up the good work!

Hi, when using Flask-SocketIO I occasionally get the following error on the backend

Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/gevent-1.1b5-py2.7-macosx-10.6-intel.egg/gevent/pywsgi.py", line 792, in handle_one_response
    self.run_application()
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/gevent-1.1b5-py2.7-macosx-10.6-intel.egg/gevent/pywsgi.py", line 778, in run_application
    self.result = self.application(self.environ, self.start_response)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/flask_socketio/__init__.py", line 37, in __call__
    start_response)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/engineio/middleware.py", line 47, in __call__
    return self.engineio_app.handle_request(environ, start_response)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/socketio/server.py", line 303, in handle_request
    return self.eio.handle_request(environ, start_response)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/engineio/server.py", line 242, in handle_request
    socket = self._get_socket(sid)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/engineio/server.py", line 340, in _get_socket
    raise KeyError('Session is disconnected')

It seems to be related to the server being occupied and so being unable to deal with emits from the front-end, but I actually don't do any emits from the front-end, any suggestions?

It also reconnects after about a half-second, but it's still not great UX-wise

I'm new in developing and Flask I had 2 projects during my course , the error occurs in the second one only and only when socket.io exist , it's an empty project but Flask behaves very weird.

for example, every time I run Flask without socket IO it reads something like this

D:\WORK\study sc5\project1\project1>flask run
Serving Flask app "hello"
Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

in project 2 we had to work with socket.io and I know it's the reason because I deleted its line and the weird behavior were gone , also no errors when I ran the socket IO application I get

D:\WORK\study sc5\project2\project2>flask run
 * Serving Flask-SocketIO app "application"

that is it after a while I get

[WinError 10053] An established connection was aborted by the software in your host machine
Sun Oct  7 23:47:57 2018 {'REMOTE_ADDR': '127.0.0.1', 'REMOTE_PORT': '56449', 'HTTP_HOST': '127.0.0.1:5000', (hidden keys: 23)} failed with ConnectionAbortedError

with that said here is my simple python code

import os, passlib ,requests ,time

from flask import Flask, session , render_template , request,redirect,url_for
from flask_socketio import SocketIO, emit ,join_room, leave_room , Namespace
from datetime import date , datetime
from flask_session import Session
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from passlib.hash import sha256_crypt


engine = create_engine("postgres:**************************",echo=True)
db = scoped_session(sessionmaker(bind=engine))



app = Flask(__name__)
app.config["SECRET_KEY"] = 'secrettt'
#sess.init_app(app)
socketio = SocketIO(app)

class NRoom:
    def __init__(self,Rowner,Rname,Rpw):
        self.Rowner = Rowner
        self.Rname = Rname
        self.Rpw = Rpw


class MyCustomNamespace(Namespace):
def on_connect(self):
    pass

def on_disconnect(self):
    pass

def on_my_event(self, data):
    emit('my_response', data)

socketio.on_namespace(MyCustomNamespace('/test'))


@socketio.on('message')
def handle(msg):
    print(f'\n\n\n Message:{msg}\n\n\n' )
    send(msg, broadcast=True)


@app.route("/")
def index():
    return render_template("index.html")

@app.route("/guest" , methods = ["GET" , "POST"])
def guest():

    if request.method == "POST":
    nickname = request.form.get("guestname")
    session["user"] = nickname
    print(f"\n\n\n {nickname} \n\n\n\n ")

    return redirect(url_for('guest',guestname=nickname))
else:


    return render_template("guest.html")

index html file

<!DOCTYPE html>
    <html>
        <head>
            <meta charset="utf-8">
            <meta name="viewport" content="width=device-width">
            <title>welcome bk</title>
        </head>
        <body>
            <script type="text/javascript" src="{{url_for('static', filename='javascript.js')}}"></script>
            <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/socket.io/1.3.6/socket.io.min.js"></script>
            <script type="text/javascript" charset="utf-8">

            var socket = io.connect('http://' + document.domain + ':' + location.port);
            socket.on('connect', function() {
            socket.emit('my event', {data: 'I\'m connected!'});
            });
        </script>


        <script>

                document.addEventListener('DOMCOntentLoaded',function(){

                    var socket = io.connect('http://127.0.0.1:5000');

                    socket.on('connect',function() {
                        socket.send("test socketio have passed ! ");

                    });
                });

        </script>
        <form action="{{ url_for('login') }}">
             <input type="submit" value="login" />
        </form>

        <form action="{{ url_for('regist') }}">
             <input type="submit" value="regist" />
        </form>


        <form action="{{ url_for('guest') }}">
             <input type="submit" value="login as guest" />
        </form>
    </body>
</html>

tested it with chrome and Firefox

I have been planning to deploy a flask-SocketIO application into production using uwsgi server behind Nginx

Versions including relevant dependencies of my virtual environment:-

OS:-  Ubuntu 16.04.3 LTS
uWsgi:-   2.0.15 
nginx:-   1.12.2
python:- 2.7.12
Falsk:-   0.12.2
Flask-SocketIO:-  2.9.2
gevent:- 1.2.2

I am intended to run the uwsgi server through systemd and load the uwsgi configurations from a .ini file.

Here's my wsgi.py file:

from server import app
if __name__ == "__main__":
    app.run()

Here's the configuration file myproject.ini for uwsgi

[uwsgi]
module = wsgi:app

http = :5000
gevent = 1000
http-websockets = true

master = true
processes = 5

socket = myproject.sock
chmod-socket = 660
vacuum = true

die-on-term = true

Here's the myproject.service file in /etc/systemd/system

[Unit]
Description=uWSGI instance to serve myproject
After=network.target

[Service]
User=user
Group=www-data
WorkingDirectory=/home/user/myproject
Environment="PATH=/home/user/myproject/virtual_frame/bin"
ExecStart=/home/user/myproject/virtual_frame/bin/uwsgi --ini myproject.ini

[Install]
WantedBy=multi-user.target

And, finally my nginx configuration file:

 server {
    listen 80;
    server_name 10.11.201.82:5000;

    location / {
        include uwsgi_params;
        uwsgi_pass unix:/home/user/myproject/myproject.sock;
        uwsgi_ignore_client_abort on;
    }

    location /socket.io {
        include proxy_params;
        proxy_http_version 1.1;
        proxy_buffering off;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_pass http://10.11.201.82:5000/socket.io;
    }

}

Errors:-

Actually I'm getting different errors from several times.

1) IOError: unable to complete websocket handshake

Here's my project status while running:_

user@user-HVM-domU:~/myproject$ sudo journalctl -u myproject -n 20
-- Logs begin at শনি 2018-02-03 09:52:05 +06, end at রবি 2018-02-04 15:27:48 +06. --
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/flask/app.py", line 1997, i
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     return self.wsgi_app(environ, start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/flask_socketio/__init__.py"
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/engineio/middleware.py", li
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     return self.engineio_app.handle_request(environ, start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/socketio/server.py", line 3
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     return self.eio.handle_request(environ, start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/engineio/server.py", line 2
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     environ, start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/engineio/socket.py", line 8
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/engineio/socket.py", line 1
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     return ws(environ, start_response)
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:   File "/home/user/myproject/virtual_frame/local/lib/python2.7/site-packages/engineio/async_gevent_uwsgi
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]:     uwsgi.websocket_handshake()
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]: IOError: unable to complete websocket handshake
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]: [pid: 23604|app: 0|req: 21/79] 10.11.201.82 () {50 vars in 1028 bytes} [Sun Feb  4 15:27:39 2018] GET /s
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]: [pid: 23604|app: 0|req: 22/80] 10.11.201.82 () {38 vars in 784 bytes} [Sun Feb  4 15:27:39 2018] GET /so
ফেব্রু 04 15:27:39 user-HVM-domU uwsgi[23592]: [pid: 23604|app: 0|req: 23/81] 10.11.201.82 () {42 vars in 845 bytes} [Sun Feb  4 15:27:39 2018]

2) IOError: write error: uwsgi_response_writev_headers_and_body_do(): Broken pipe [core/writer.

ফেব্রু 04 15:16:53 user-HVM-domU uwsgi[23421]: [pid: 23433|app: 0|req: 52/94] 10.11.201.82 () {42 vars in 845 bytes} [Sun Feb  4 15:16:38 2018] POST /s
ফেব্রু 04 15:16:53 user-HVM-domU uwsgi[23421]: [pid: 23433|app: 0|req: 52/95] 10.11.201.82 () {38 vars in 783 bytes} [Sun Feb  4 15:16:30 2018] GET /so
ফেব্রু 04 15:16:55 user-HVM-domU uwsgi[23421]: [pid: 23433|app: 0|req: 54/96] 10.11.201.82 () {42 vars in 843 bytes} [Sun Feb  4 15:16:55 2018] POST /s
ফেব্রু 04 15:16:55 user-HVM-domU uwsgi[23421]: [pid: 23433|app: 0|req: 54/97] 10.11.201.82 () {38 vars in 783 bytes} [Sun Feb  4 15:16:53 2018] GET /so
ফেব্রু 04 15:17:08 user-HVM-domU uwsgi[23421]: Sun Feb  4 15:17:08 2018 - uwsgi_response_writev_headers_and_body_do(): Broken pipe [core/writer.c line 
ফেব্রু 04 15:17:08 user-HVM-domU uwsgi[23421]: IOError: write error
ফেব্রু 04 15:17:08 user-HVM-domU uwsgi[23421]: [pid: 23433|app: 0|req: 55/98] 10.11.201.82 () {44 vars in 867 bytes} [Sun Feb  4 15:16:08 2018] GET /so

3) Nginx error log

Last 20 line of /var/log/nginx/error.log

2018/02/04 15:24:42 [error] 23563#23563: *109 upstream prematurely closed connection while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=websocket&sid=b95aa3f7a7374706a7d09d857c1e69fe HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=websocket&sid=b95aa3f7a7374706a7d09d857c1e69fe", host: "10.11.201.82"
2018/02/04 15:25:40 [error] 23560#23560: *83 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=polling&t=1517736280486-2&sid=998d555f29cc49f3949bf080b5c2820c HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736280486-2&sid=998d555f29cc49f3949bf080b5c2820c", host: "10.11.201.82", referrer: "http://10.11.201.82/"
2018/02/04 15:25:49 [error] 23563#23563: *98 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=polling&t=1517736289238-36&sid=6535da975fee43bdb49be5f061e04522 HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736289238-36&sid=6535da975fee43bdb49be5f061e04522", host: "10.11.201.82", referrer: "http://10.11.201.82/"
2018/02/04 15:25:50 [error] 23563#23563: *138 upstream prematurely closed connection while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=polling&t=1517736290606-40&sid=c13d0711b34b49cb8d5d973642369c33 HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736290606-40&sid=c13d0711b34b49cb8d5d973642369c33", host: "10.11.201.82", referrer: "http://10.11.201.82/"
2018/02/04 15:25:54 [error] 23563#23563: *143 upstream prematurely closed connection while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=polling&t=1517736294273-52&sid=aec315362ea644fe93035f7d8c5519a6 HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736294273-52&sid=aec315362ea644fe93035f7d8c5519a6", host: "10.11.201.82", referrer: "http://10.11.201.82/"
2018/02/04 15:25:56 [error] 23560#23560: *83 upstream prematurely closed connection while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "GET /socket.io/?EIO=3&transport=polling&t=1517736346555-72&sid=933777c0ced64dc4a459b1ebe33a0d21 HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736346555-72&sid=933777c0ced64dc4a459b1ebe33a0d21", host: "10.11.201.82", referrer: "http://10.11.201.82/"
2018/02/04 15:25:56 [error] 23560#23560: *83 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 10.11.201.82, server: 10.11.201.82, request: "POST /socket.io/?EIO=3&transport=polling&t=1517736356497-73&sid=933777c0ced64dc4a459b1ebe33a0d21 HTTP/1.1", upstream: "http://10.11.201.82:5000/socket.io/?EIO=3&transport=polling&t=1517736356497-73&sid=933777c0ced64dc4a459b1ebe33a0d21", host: "10.11.201.82", referrer: "http://10.11.201.82/

Miguel I've tried launching your example on folder and uploaded it up to heroku. here https://test-socketz.herokuapp.com/

I changed this line 13 on the index.html

var socket = io.connect('https://' + document.domain + ':' + location.port + namespace); from http to https since heroku complains if it's only on http

besides that I did not change anything. the app will keep disconnecting and reconnecting and clicking echo will sometimes work and sometimes not work.

I just got weird behaviour, after which server broke down, but that might not be the reason...

Anyway, this looks weird:

2018-04-07 19:55:10.029414 :: DEBUG :: dashlogger :: unknown :: Disconnect event
2018-04-07 19:55:10.032317 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193/m4_30902513941193
2018-04-07 19:55:10.032526 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193 None
2018-04-07 19:55:10.061720 :: DEBUG :: dashlogger :: unknown :: Disconnect event
2018-04-07 19:55:10.064122 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193/m4_30902513941193
2018-04-07 19:55:10.064372 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193 None
2018-04-07 19:55:10.094230 :: DEBUG :: dashlogger :: unknown :: Disconnect event
2018-04-07 19:55:10.096855 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193/m4_30902513941193
2018-04-07 19:55:10.097039 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193 None
2018-04-07 19:55:10.154927 :: DEBUG :: dashlogger :: unknown :: Disconnect event
2018-04-07 19:55:10.157444 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193/m4_30902513941193
2018-04-07 19:55:10.157622 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193 None
2018-04-07 19:55:10.342673 :: DEBUG :: dashlogger :: unknown :: Disconnect event
2018-04-07 19:55:10.345215 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193/m4_30902513941193
2018-04-07 19:55:10.345395 :: DEBUG :: dashlogger :: unknown :: m4_30902513941193 None 

And it goes on for a few seconds. And not just for this client, but others as well. It just keeps disconnecting without connection events, and within milliseconds, I'm frustrated :D

Granted, there was some work going on with those clients, but there's no physical way to reconnect within 0.01 ms and lose connection again...

I'm having trouble using socket io on one of my server machines. On my server side python code logging info, it shows that the server is emitting messages to the client, but on the client side, the client doesn't seem to receive anything. and it shows the error "failed: WebSocket is closed before the connection is established." in the console followed by a series of "400 (BAD REQUEST)". It also returns "failed: Error during WebSocket handshake: Unexpected response code: 400" sometimes

I tried on my own machine and it only works when I refresh the page (the client page does not receive anything if I close it and open it again, but it does if I refresh it again).

Before Flask-WebSocketIO, I was able to start Flask like so:

app.run(
    debug=os.environ.get('FLASK_DEBUG'),
    host=os.environ.get('FLASK_RUN_HOST'),
    port=os.environ.get('FLASK_RUN_PORT'),
    ssl_context=(
        os.environ.get('FLASK_RUN_CERT'),
        os.environ.get('FLASK_RUN_KEY'),
    )
)

With Flask-WebSocketIO, I have to start it like so:

socketio.run(
    app,
    debug=os.environ.get('FLASK_DEBUG'),
    host=os.environ.get('FLASK_RUN_HOST'),
    port=int(os.environ.get('FLASK_RUN_PORT')),
    certfile=os.environ.get('FLASK_RUN_CERT'),
    keyfile=os.environ.get('FLASK_RUN_KEY'),
)

Mind int(), and ssl_context dropped in favor of certfile/keyfile.

• Without int(), I'd get: TypeError: 'str' object cannot be interpreted as an integer.
• With ssl_context, I'd end up with AttributeError: 'tuple' object has no attribute 'wrap_socket'.

Describe the solution you'd like

I would suggest updating the arguments to socketio.run() to accept the same as app.run() did for ease and comfort.

Is your feature request related to a problem? Please describe. I'm developing a little game server based on an underlying flask-socketio and the client relies on a python-socketio client

During unit testing, I want to provide my game client with a SocketIOTestClient instead of a socketio.Client thanks to socketio.test_client(...) Problem: the interface and life cycle is not exactly the same as python-socketio client, so I have to do many twists to get it compatible, namely on 3 points:

• connect(...) doesn't take a url parameter
• the mocked client is provided already connected, and subsequent calls to connect(...) are ignored, so I can't directly test my connection process
• the mocked client doesn't have an sid provided, so can't use this as a reference in the upper layers (the fame client)

Describe the solution you'd like

1. add an 'url' parameter to SocketIOTestClient.connect(...) to mimic the signature from python-socketio Client.connect(...). The url can be ignored.
2. test_client() returns a test client that claims to be not already connected, and the connection simulation happens only when connect(...) is called. 2bis. the connection simulation adds an sid attribute and set it during SocketIOTestClient.connect

to avoid breaking compatibility with existing use of test_client(), we could even have an alternative test_unconnected_client()

Describe alternatives you've considered

• running a server the regular way -> since shutting it seem to be very complicated, not going there
• create another SocketIOTestClient variant and use it on my side. Not fun

any clarification needed? thoughts?

i have a python socketio client connected to a flasksocketio server which works fine for about 4 hours , after which there is a rolling increase in delay until the messages almost trickle down , and then there is a burst of message . there are about 10 -12 messages being transmitted every second on the same connection , willing to share the code for server and client if needed . Any help is appreciated.

Thanks and Regards!! Cheerss!!!

I have a (sightly unusual use case) running well. It needs to be a threaded application - but it's single user local interface for another project. I start the server using start_background_task() in which I run flask_SocketIO.SocketIO.run(app). I shutdown the server by sending an event which calls flask_SocketIO.SocketIO.stop(). This all works cleanly at exit.

However I learned from the debug logs, stop() looks for werkzeug's shutdown method - which is deprecated. Will the threaded / werkzeug shutdown mechanism be updated?

Hello,

My python socketio client will not connect to my flask socketio server, however my js client does.

Server code:

from flask import Flask
from flask_socketio import SocketIO

app = Flask(__name__)
socketio = SocketIO(app)

@app.route('/')
def home():
    return app.send_static_file('index.html')

@socketio.on('message')
def handle_message(data):
    socketio.send(data)

@socketio.on('connect')
def on_connection():
    print('client connected connected')

if __name__ == '__main__':
     socketio.run(app, host = 'myIP', port = '443', debug = True, keyfile = 'KEYFILELOCATION', certfile = 'CERTFILELOCATION', server_side = True)

Python Client code:

import socketio

sio = socketio.Client()
sio.connect('https://myIP:443',  wait=True, wait_timeout= 5)
sio.send("test")

JS Client Code:

var sio = io.connect('https://myIP:443')
sio.send("test")

The error:

raise exceptions.ConnectionError(
engineio.exceptions.ConnectionError: HTTPConnectionPool(host='myIP', port=443): Max retries exceeded with url: /socket.io/?transport=polling&EIO=4&t=1635512584.756163 (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x00000220CC652C10>: Failed to establish a new connection: [WinError 10061] No connection could be made because the target machine actively refused it'))

PIP freeze: python-socketio==5.4.1 python-engineio==4.3.0 Flask-SocketIO==5.1.1