WebSockets with nginx + uwsgi + flask-socketio

Question

I'm trying to establish a websocket connection using socket.io on the frontend and Flask-Socketio on the backend. However, the frontend is giving me the error

WebSocket connection to 'ws://myserver.com/socket.io/?EIO=3&transport=websocket&sid=0514a0aa99f346e7ad717770f9911c89' failed: WebSocket is closed before the connection is established.

I have a feeling this is due to my uwsgi or nginx config.

Here's the uwsgi config I'm using:

[uwsgi]
base = /var/www/webapp
file = %(base)/run.py
callable = app
pythonpath = %(base)
socket = /tmp/uwsgi.sock
chmod-socket = 666
http-websockets = true
gevent = 1000
processes = 1
threads = 2
enable-threads = true
single-interpreter = true
master = true
chdir = /var/www/webapp
fs-reload = %(base)/app/
touch-reload = %(base)/run.py
py-autoreload = 1
harakiri = 3600

and here's the relevant portion of the nginx config:

    location /socket.io/ {
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/.htpasswd;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
        include uwsgi_params;
        uwsgi_pass unix:/tmp/uwsgi.sock;
    }

Is there an issue with using the

socket = /tmp/uwsgi.sock

from the uwsgi config with the

uwsgi_pass unix:/tmp/uwsgi.sock;

from the nginx config? Any help would be greatly appreciated. Of course, please let me know if I need to provide more information.

Answer 1

You should change uwsgi_pass unix:/tmp/uwsgi.sock; to uwsgi_pass unix:///tmp/uwsgi.sock;.