Nginx WebSocket proxy

nginx.conf

#   To turn a connection between a client and server from HTTP/1.1 into WebSocket,
# the protocol switch mechanism available in HTTP/1.1 is used.
# There is one subtlety however: since the “Upgrade” is a hop-by-hop header,
# it is not passed from a client to proxied server. 

    location /websocket {
        proxy_pass https://url/websocket;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-Proto https;
        proxy_redirect off;
    }