Host Registration - Install packages

[stejskalleos]

New host macro :manage_packages for package installation
on supported OS families: Red Hat, Debian & Suse.

In host registration users can now install packages
on the host by setting the host_registration_packages.

[theforeman-bot]

Issues: #31743

[stejskalleos]

@ekohl updated & rebased
Removed manage_packages macro, now just using snippet_if_exists.
Added dnf support for Fedora and dropped support for SUSE (Global Registration don't support it yet).

[ares]

It seems we ship the snippet and only activate it if host param is defined. In such case, we should use snippet instead of snippet_if_exists. I think the idea with macro wasn't bad, it was the combination with the snippet that caused confusion. I think we should provide some reasonable way to install package (macro or snippet) and then, use it here. That template has already more logic, e.g. for suse.

So I wonder, would it be better to take the content of the linked job template and convert it to macro in core? No snippet involved. The package list is based on the parameter. The only downside is, user can't extend it without Foreman code core change.

Also we could then use the same macro in our provisioning templates, where we today use snippet_if_exists logic, which was probably the motivation to do it the same way here.

[ares]

Given the above, next steps:

1. @ekohl @stejskalleos do we prefer macro or snippet? I vote for macro
2. @stejskalleos would it be possible to base the implementation on the linked job template and modify that afterwards so it uses internally macro/snippet? I think that would payback long term

[ekohl]

I think that in principe a macro is a good idea, but I did struggle with the use of a snippet. We are providing an API with it. How clear is it to the user that if they make changes to that template, they can change the API?

One thing to consider: the commit message says "after host registration" but it calls built after installing packages. Perhaps during instead of after is a better description?

I would also consider solving this in a more generic way: don't include a parameter by default but give the user a generic snippet_if_exists 'registration_linux_post' so they can customize their registration via their own snippet.

[ares]

Ok, so to summarize

1. let's add the macro, no snippet involved, based on the code in job template
2. let's use this macro to install packages specified in the parameter called e.g. additional_packages in linux registration template
3. ideally add the same thing to the kickstart templates
4. add <%= also snippef_if_exists 'registration_linux_post' %> to the linux registration template, so users can further customize the registration without modifying the default template
5. let's modify the rex job template to use that macro (that's rex repository work)

please speak up if I misunderstood

[ekohl]

ideally add the same thing to the kickstart templates

In kickstart you have 2 types of package installation: the native %packages section which also gives you a nice progress bar. However, it's generally not usable on RHEL due to subscriptions (though since RHEL 8.2 Anaconda understands activation keys so there it can be done, our kickstarts don't understand this).

I'd expect preseed to have something similar.

I'd be ok with leaving it out of scope for now.

Other than that 👍

[stejskalleos]

@ares @ekohl
Updated according to #8298 (comment)

[ares]

Looks good, I'd just wait for the renaming PR to get in and rename things here so we don't have to rename again after merge.

[stejskalleos]

@ekohl @ares Rebased & updated

Added banner, Fedora & RHEL >=8 use dnf, fixed condition for subman on debian.

[ares]

getting closer and closer :-) two small things and I'll test the whole thing

[ares]

I have tested the functionality and all works fine including the snippet. Leaving this open for a few days or until other reviews confirm concerns are addressed. If I don't see any reaction I plan to merge this by the end of the week.

[ares]

Thanks @stejskalleos, merged and updated the commit message to reflect the new names