chore: Put files in /etc/ instead in /usr/etc

[fiftydinar]

This modifies build-time part of modules to work with /etc/ instead of /usr/etc/

Related PR:
blue-build/template#38
blue-build/website#65

[fiftydinar]

I think that this needs to be tested for regressions, since I couldn't copy to /etc/hosts, but could to /usr/etc/hosts in my image unrelated to this PR.

The error I got was Read-only filesystem

[xynydev]

I think that this needs to be tested for regressions

Is this OK to merge then or do we need to do something first?

[fiftydinar]

I think that this needs to be tested for regressions

Is this OK to merge then or do we need to do something first?

Have to test all modules for regression, but signing module the most.

Since Ublue images don't copy policy.json to /etc/ in build-time as an exception (they have issues with ublue-os-signing RPM clashing with containers-common RPM policy.json)
ublue-os/config#311

[fiftydinar]

There is a regression in signing module right now:

I get this error:

#51 0.081 cp: cannot stat '/usr/share/ublue-os/cosign.pub': No such file or directory

When reverting to the current signing module state, it works again.

Everything else works.

The workaround is to keep signing module copying to /usr/etc/ temporarily (as it is), until Ublue solves this issue

EDIT: Done the workaround

[fiftydinar]

This is ready to merge now (when other PRs get approved too)

[gmpinder]

I think the signing module is busted until this gets merged in BTW

[xynydev]

Ready to merge, if CLI is ready @gmpinder

Merge order:

1. chore: Put files in /etc/ instead in /usr/etc #315
2. chore: Recommend the usage of /etc/ instead of /usr/etc/ template#38
3. docs: Create a new blog post for /usr/etc/ to /etc/ website#65

[fiftydinar]

@xynydev CLI is ready, time to merge stuff