WHAT IS DOKKU?
Dokku is an extensible, open source Platform as a Service that runs on a single server of your choice.
To start using Dokku, you’ll need a system that meets the following minimum requirements:
- A fresh installation of Ubuntu 16.04 x64, Ubuntu 14.04 x64, Debian 8.2 x64 or CentOS 7 x64 (experimental) with the FQDN set 
- At least
1GBof system memory 
You can optionally have a domain name pointed at the host’s IP, though this is not necessary.
Dokku is designed for usage on a fresh VM installation, and should install all necessary dependencies if installing via the bootstrap method.
Dokku – Heroku on Docker