

The cli.
I have used management interfaces like coxkpit in the last but i do not really like it that much. I have E-Mail Notifications setup for updates via aptitude and monitor using prometheus and grafana and get additional notifications via prometheus alarm manager.
For an easy to use docker interface i use dockge, since i found it in this use case to be faster with a good, working, independend Interface.
But for the Linux underneath, for all 10-20 servers i managae, CLI.


Yes.
And then the maintainers of the package on the package repository you use will release the patch there. Completely standard operation.
I recommend younto read up on package repositories on Linux and package maintainers etc.