The screencast shows how you can get a fully working installation of GitLab, using system packages, just by entering a few details in interactive wizards.
The demo does not show the creation and push/pull on repositories because GitLab UI does not work in a text-based browser such as lynx. But it works ;-)
Using system packages allows anyone to keep their installation secure by regularly upgrading their system with the security fixes provided by their distribution.
Note: you should probably view the screencast in full screen since I forgot to reduce my terminal size before recording (the wizards appear weird).