Under tornado v4+ WebSocket connections get refused with 403

Question

I have an older tornado server that handles vanilla WebSocket connections. I proxy these connections, via Nginx, from wss://info.mydomain.com to wss://mydomain.com:8080 in order

Answer 1

I would like to propose and alternative solution, instead of messing with the tornado application code, I solved the issue by telling nginx to fix the host header:

location /ws {
proxy_set_header Host $host;
proxy_pass http://backend;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}