All in all, the installation instructions made it pretty easy to get icinga2 up and running on a RaspberryPI 4. The Icinga Web instructions are pretty good as well. Thank you for posting them. I would like to provide some feedback on a portion of the instructions.
I have limited experience working with databases. Happily, the installation instructions guide me fairly well (once I figured out that I need mariadb for my database since mysql is not available for Buster Raspbian). The database commands were fed to me and I was able to create the databases.
Once I hit the web setup, my first issue was setting up an icingaweb2 group (can’t say that I saw that I needed to do this in the instrucitons). Once I set /etc/icingaweb2 to the icingaweb2 group, I could log in.
The setup then proceeds to ask me several questions about users, database names, etc. So far, it looks like there are three sets of credentials I need and it’s not clear which ones to use. I think there are some things that happen in the “apt install” steps that are not transparent to the user. It took some digging in the database to figure out what to do. It would be nice if the instructions were updated to say "this step is creating this database for this user – when the web setup asks you for “xxxxx”, then you should use this user and database.
Perhaps all of this is more obvious to a seasoned database engineer but that is not me. You could require some background for the installation, but I believe with some small modifications to the documents, this domain knowledge would not be required.
Perhaps one approach would be to create a section on permissions that describes the OS permissions required for each directory and the DB permissions required. That section would also need to have names for each of the accounts and databases that correlate with the web setup wizard instructions.
Thanks again for providing these tools.