fix(systemd-sysext): handle confexts and correct extensions search path

[aafeijoo-suse]

• Support to confexts added in confext: extension of sysext systemd/systemd#26013 (instead of working on /usr and /opt, confext will extend only /etc).

• /usr/lib/extensions/ not supported since systemd/systemd@de862276

• In addition to these two fixes, add only raw binary disk images contained in regular .raw files, because dracut does not have a helper function to add directories recursively.

Checklist

• I have tested it locally
• I have reviewed and updated any documentation if relevant
• I am providing new code and test(s) for it

[stale]

This issue is being marked as stale because it has not had any recent activity. It will be closed if no further activity occurs. If this is still an issue in the latest release of Dracut and you would like to keep it open please comment on this issue within the next 7 days. Thank you for your contributions.

[LaszloGombos]

• Support to confexts added in confext: extension of sysext systemd/systemd#26013

This link is not working for me. Perhaps systemd/systemd#24864 ?

I assume a purpose of this module is to load a systemd sysext extension in initramfs.

What would be a practical typical scenario where a boot would require loading systemd sysext extension during the initramfs phase and not after the chroot ?

[aafeijoo-suse]

• Support to confexts added in confext: extension of sysext systemd/systemd#26013

This link is not working for me. Perhaps systemd/systemd#24864 ?

No, the previous link is ok (systemd/systemd#26013), maybe you ran into temporary GitHub issues.

I assume a purpose of this module is to load a systemd sysext extension in initramfs.

What would be a practical typical scenario where a boot would require loading systemd sysext extension during the initramfs phase and not after the chroot ?

Excerpt:

The ‘confext’ concept follows the same principle as the sysext functionality. sysext allows to extend the host filesystem (or a unit’s) at runtime with signed images that add new files to /usr and /opt, using OverlayFS. In the same fashion, confext will extend /etc (and only /etc).

• Call using the same systemd-sysext binary: https://github.com/systemd/systemd/blob/5f655ffb1557aa9b20b3db7bc6fe28fe3b9c34cd/src/sysext/sysext.c#L1079

• systemd-confext.service ordered before initrd-switch-root.target: https://github.com/systemd/systemd/blob/5f655ffb1557aa9b20b3db7bc6fe28fe3b9c34cd/units/systemd-confext.service#L23-L24