lorax: Fall back to erofs if mksquashfs is not installed

[brlane-rht]

This switches the requirement on squashfs-tools to a 'Recommends' so that if it is missing lorax will still be installed.

It checks that mksquashfs is available when the rootfs-type is squashfs or squashfs-ext4, if it is not it falls back to rootfs and checks to make sure mkfs.erofs is available.

The default rootfs-type is still squashfs, and can still be overridden using --rootfs-type=erofs.

Resolves: RHEL-68936

[coveralls]

Coverage Report for CI Build 25018088474

Coverage decreased (-0.2%) to 41.321%

Details

• Coverage decreased (-0.2%) from the base build.
• Patch coverage: 17 uncovered changes across 2 files (0 of 17 lines covered, 0.0%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
src/pylorax/cmdline/livemedia.py	9	0	0.0%
src/pylorax/cmdline/lorax.py	8	0	0.0%

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	3931
Covered Lines:	1643
Line Coverage:	41.8%
Relevant Branches:	2124
Covered Branches:	859
Branch Coverage:	40.44%
Branches in Coverage %:	Yes
Coverage Strength:	0.42 hits per line

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💛 - Coveralls

[brlane-rht]

@M4rtinK @yselkowitz what do you think?

[yselkowitz]

erofs is supposed to be the first choice nowadays: https://fedoraproject.org/wiki/Changes/EROFSforLiveMedia

So the spec file change makes sense, but I'm not sure about the code. If --rootfs-type=squashfs is specified but mksquashfs is not present, shouldn't that be an error? Or does that only make sense if erofs is the default, which currently it isn't? And why isn't erofs the default now?

[brlane-rht]

That change is for kiwi, not lorax/livemedia-creator. releng still hasn't switched the boot.iso to erofs. So I'm trying to keep things working as-is, but also nicely deal with removing squashfs-tools in ELN.
Lorax doesn't set the policy, if someone wants to keep using squashfs they should be able to, until the package is dropped.