WebSocket Proxy - Nginx

Proxy ws://example.com/ws/ to ws://localhost:7890/

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    listen 80;
    server_name example.com;

    # ...

    location /ws/ {
        proxy_pass http://localhost:7890/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_set_header Host $host;
    }
}

Ref: Nginx WebSocket

Proxy all WebSocket request to ws://localhost:7890/

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    listen 80;
    server_name example.com;

    location /websocket/ {
        internal;

        proxy_pass http://localhost:7890/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    }

    location / {
        set $websocket 1;
        if ($http_connection !~* "upgrade") {
            set $websocket 0;
        }
        if ($http_upgrade !~* "websocket") {
            set $websocket 0;
        }
        if ($websocket) {
            rewrite ^ /websocket$uri last;
        }

        # ...
    }
}