How to automatically join Ubuntu clients to a Univention Corporate Server domain

Univention Corporate Server (UCS) provides a shared trust and security context called a domain. This means, the members of the domain know and trust each other. To get access to resources and services provided within the domain, users and computers have to join the domain.
Linux clients, such as Ubuntu and its derivates, could be joined to a UCS domain for a long time, but it always involved a rather long process of copying commands from the Univention documentation to the command line of the involved systems.

In April of 2018 Univention released the new “Ubuntu Domain Join Assistant” which provides both a graphical interface, making the whole join process a lot easier and time-saving, but also a CLI tool to automate the domain join of many Ubuntu clients.
Let‘s get started – the graphical way:
Let‘s assume we just installed a Univention Corporate Server in the current version of 4.3 and a plain Ubuntu 18.04 client – both with an out-of-the-box feature set and without any modifications. Using the optional software component “DHCP server” in UCS is not strictly necessary, but recommended.

Now log in to your Ubuntu client with a user. To install in Ubuntu 18.04/16.04/14.04/Linux Mint 19/18/17 open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

Terminal Commands:
sudo add-apt-repository ppa:univention-dev/ppa
sudo apt-get update
sudo DEBIAN_FRONTEND=noninteractive apt-get install univention-domain-join