A common use case is to use Dokku without an actual domain. I address how to use a consistent external port with an ip address since the docs don't.
Dokku isn't clear how to host a server when you don't have a domain you want to use. If you don't enable their vhost by default then the external port of your app CHANGES EVERY DEPLOY. They only describe in detail their http://subdomain.domain.com deploy. Here I show you how to use the http://ipaddress:port deploy in a consistent . . .