Add an option run checks only and exit

[ehelms]

The intent is to at least allow two scenarios:

1. Users that want to be able to run checks before committing to a full install
2. Allowing foreman-maintain to run the installer checks as part of it's health checks rather than re-implementing the checks

[evgeni]

Didn't we discuss (2) and end up with "this introduces a chicken-egg situation, where people want to run checks before they upgrade, but the new checks require the new installer to be present"?

I'm cool with the feature as such, just wonder if we're really getting (2) out of it.

[ehelms]

Didn't we discuss (2) and end up with "this introduces a chicken-egg situation, where people want to run checks before they upgrade, but the new checks require the new installer to be present"?

I'm cool with the feature as such, just wonder if we're really getting (2) out of it.

Correct - this won't help with new checks in the installer. I was thinking about existing checks that are more persistent? Specifically, I have seen multiple requests to have foreman-maintain health check do a hostname check. I suppose I could just copy that code into foreman-maintain but thought I'd consider this route first and see what others think.

[evgeni]

Oh, okay, that it would help with.

[ehelms]

@ekohl Any thoughts to adding this feature?

[ekohl]

Overall I think this makes sense. Some small implementation details inline.

[ekohl]

I'd argue this is info, not notice. https://en.wikipedia.org/wiki/Syslog#Severity_level says for notice:

Conditions that are not error conditions, but that may require special handling.

And info:

Confirmation that the program is working as expected.

[ehelms]

The problem we always have is that we had to use NOTICE because of how puppet uses INFO and that forced our hand to break some of these rules in order to provide users with useful information. Notice is our default, and I believe that this is a useful output for default state, especially when running checks only or the output feels like nothing actually happened:

2024-04-18 14:08:27 [NOTICE] [root] Loading installer configuration. This will take some time.
2024-04-18 14:08:32 [NOTICE] [root] Running installer with log based terminal output at level NOTICE.
2024-04-18 14:08:32 [NOTICE] [root] Use -l to set the terminal output log level to ERROR, WARN, NOTICE, INFO, or DEBUG. See --full-help for definitions.
2024-04-18 14:08:33 [NOTICE] [checks] System checks passed

vs.

2024-04-18 14:08:27 [NOTICE] [root] Loading installer configuration. This will take some time.
2024-04-18 14:08:32 [NOTICE] [root] Running installer with log based terminal output at level NOTICE.
2024-04-18 14:08:32 [NOTICE] [root] Use -l to set the terminal output log level to ERROR, WARN, NOTICE, INFO, or DEBUG. See --full-help for definitions.