Howtoforge published a tutorial about installing GitLab with Docker on Ubuntu 20.04 LTS.
How to Install GitLab with Docker on Ubuntu 20.04 LTS
In this tutorial, we will show you how to install GitLab using the Docker and Docker Compose. Also, we will be using the Ubuntu 20.04 as our primary operating system, and install docker from the official Ubuntu FocalFossa repository.
How to Install GitLab with Docker on Ubuntu 20.04 LTS