Пример конфигурации для websocket vhost, при использовании nginx как proxy.

wsvhost.conf

server {
    listen       80;
    server_name  ws.mysite.com;
    access_log   off;
    return 301 https://$server_name$request_uri;
}

upstream wsserver {
    ip_hash;

    server <WEB_SOCKET_SERVER>; # В формате HOST:PORT (Например: 123.123.123.123:9999)

    keepalive 512;
}

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

server {
    listen          443 ssl;
    server_name     ws.mysite.com;

    ## Strong SSL Security
    ## https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html & https://cipherli.st/
    ssl on;
    ssl_certificate /etc/nginx/ssl/ws.mysite.com/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/ws.mysite.com/privkey.pem;

    ssl_ciphers EECDH:+AES256:-3DES:RSA+AES:RSA+3DES:!NULL:!RC4;
    ssl_protocols TLSv1.1 TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 5m;

    proxy_next_upstream error;

    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Scheme $scheme;
    proxy_set_header Host $http_host;

    # Это для LetsEncrypt
    # Удобнее инклудить
    # include conf.d/acme.block;
    # но для пример оставил так
    location /.well-known {
        root /etc/letsencrypt;
    }

    # Пример от centrifugo, поэтому endpoint такой,
    # но может быть любой.
    # Этот endpoint используется при создании new WebSocket(...)
    location /connection {
        proxy_pass http://wsserver;
        proxy_buffering off;
        keepalive_timeout 65;
        proxy_read_timeout 60s;
        proxy_http_version 1.1;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Scheme $scheme;
        proxy_set_header Host $http_host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    }

    location / {
        proxy_pass http://wsserver;
    }
}