Websocket 502 Bad Gateway - django

Question

I've two container wsgi and asgi.
wsgi server is running on 127.0.0.8000:
gunicorn app.wsgi:application --bind 127.0.0.1:8000
Also asgi server is running on 127.0.0.1:8001 using of daphne:
daphne -b 127.0.0.1 -p 8001 app.asgi:application
I have a websocket request like this:
wss://app.example.com/ws/chat/f770eef/
But unfortunately these errors occur in the system:
i) nginx log says:
2022/05/22 13:15:29 [error] 463129#463129: *9 upstream prematurely
closed connection while reading response header from upstream, client:
11.198.111.11, server: app.example.com, request: "GET /ws/chat/f770eef/
ii) Requests do not reach daphne.
asgi.py
import os
from django.core.asgi import get_asgi_application
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')
application = get_asgi_application()
nginx cofing:
server {
listen 443;
listen [::]:443;
server_name app.example.com;
root /var/www/html;
...
location /ws/ {
proxy_pass http://127.0.0.1:8001;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
proxy_read_timeout 300s;
proxy_connect_timeout 75s;
}
...
}

Answer 1

I had the same problem with my setup. changing the the proxy_pass setting to HTTPS instead of http fixed it for me.
...
proxy_pass https://127.0.0.1:8001;
...
Since you're using WSS, thats WS over SSL protocol so HTTP doesn't cut it and I guess Nginx or some other service terminates the connection