I recently decided to spend some time refreshing my Red Hat knowledge because it has been a while since I have supported production Red Hat based servers. A lot has changed. You can signup for a developer license for free and get limited access to Red Hat products.
Registration, among other things, controls the repos that the server can use. For instance, you cannot run ‘dnf update’ until the system is registered and attached to the available desired software repositories. The ‘subscription-manager’ command exists to handle various subscription configuration situations.
For a basic free developer subscription, the following will get things started from the command line.
Show the various commands available to the subscription manager command:
subscription-manager
Subscribe and configure the available repos. This can apparently be used with kickstart as well:
subscription-manager register --username --password --auto-attach
Update the system:
dnf update
There is a lot more to subscription manager based on workflows, hosted repositories, configurations, etc. Because of different workflows, registration can also be performed via the GUI, web console, automation, etc.