Django app without port number

What you've described is known as a reverse proxy, and you can set that up using a very slim and simple config file as described in the guide below:

• Use NGINX as a Reverse Proxy | Linode

In short, you would create a file /etc/nginx/conf.d/$NAME_OF_APP.conf with the following values:

server {
  listen 80;
  listen [::]:80;

  server_name $DOMAIN_NAME.TLD;

  location / {
      proxy_pass http://localhost:$APP_PORT_NUM/;
  }
}

Swapping in your domain name for $DOMAIN_NAME.TLD and the port number your app uses for APP_PORT_NUM, respectively.

My colleague Tim's post covers much of the same basics, but goes much deeper into adding SSL/HTTPS encryption for your app:

• Add https to my Django website in Linode server | Linode Questions