Поднимаем VPN-туннель из мира домой в обход NAT

server {
        listen 80;
        listen [::]:80;
        server_name vasya.pupkin.com;
        root /www/pupkin.com/vasya/public;

        charset utf-8;
        client_max_body_size 1m;

        location / {
                index index.php;
                try_files $uri $uri/ /index.php?$args;
        }
        ...
        ...
}

server {
        listen 80;
        listen [::]:80;
        server_name petya.pupkin.com;

        charset utf-8;
        client_header_timeout  10m;
        client_body_timeout    10m;
        client_max_body_size   10m;
        send_timeout           10m;

        location / {
                proxy_set_header X-Forwarded-Host $host;
                proxy_set_header X-Forwarded-Server $host;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_pass http://192.168.16.44:7990;
                port_in_redirect off;
                proxy_redirect http://192.168.16.44:7990/ http://petya.pupkin.com/;
        }
}