Hey @Joda
So the difference is, the “old” guide is about Foreman explicitly, and then there was a plugin documentation for Katello on top.
You can also see that if you are looking at the nightly docs, there are also the docs for Ubuntu/Debian
Which means with the current release of Foreman 3.6 there is support for:
- EL 8 (RHEL, Rocky Linux, AlmaLinux, CentOS Stream, …)
- Debian 11
- Ubuntu 20.04 LTS
And if you want to install Foreman + Katello there is currently support for the EL 8 platforms.
So if you need Katello (package management) you will have to use one of the EL 8 platforms If you don’t you can use Ubuntu 20.04.
22.04 has some packages in the repos that are too new for the application, the same also counts for EL 9. But the team is hard at work to get the support in. You can track that here!