Proxy a Node.js app through Nginx

node.nginxconf

upstream app_name {
  # where the app is running
  server 127.0.0.1:3000;
}

server {
  listen 0.0.0.0:80;
  server_name domain.com;
  access_log /var/log/nginx/app_name.log;

  location / {
    proxy_http_version 1.1;

    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_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";

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