mysite.conf

upstream app_yourdomain {
    server 127.0.0.1:8081;
}

server {
    listen 0.0.0.0:80;
    server_name mydomain.com www.mydomain.com;
    access_log /var/log/nginx/nodeApp.log;

    location ~ ^/(images/|img/|javascript/|js/|css/|stylesheets/|flash/|media/|static/|robots.txt|humans.txt|favicon.ico) {
      root /home/nodeApp/public;
      access_log off;
      expires max;
    }

    location /subfolder/ {
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_set_header X-NginX-Proxy true;

      proxy_pass http://app_yourdomain/;
      proxy_redirect off;
    }
 }