server {
    listen       80;
    server_name  dominio.com;

    # proxy to Apache 2
    location / {
        proxy_pass         http://127.0.0.1:81/;
        proxy_redirect     off;

        proxy_set_header   Host             $host;
        proxy_set_header   X-Real-IP        $remote_addr;
        proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        proxy_max_temp_file_size 0;
    }