Allow importctl to place images under /run

[tchx84]

Component

other

Is your feature request related to a problem? Please describe

Currently, importctl pull-raw, pull-tar, import-raw, import-tar and import-fs operations can only place images under /var/lib. As I understand it, images placed under /var/lib are kept activated even after system reboots.

Myself, along with other members of the GNOME community (CC @alatiera), are currently exploring ways of using multiple pieces of systemd, including importctl, to provide a better and safer experience to develop and test system components on immutable systems.

We would like to simplify as much as possible the steps required to recover from potentially system-breaking changes.

Describe the solution you'd like

To achieve this in a safer way, I am wondering if we would be open to extend importctl to allow placing images under /run as well, e.g., and be just a simple system reboot back to safety.

e.g., importctl import-raw --class=sysext --runtime component.sysext.raw component, would result in /run/extensions/component.raw

Describe alternatives you've considered

Writing some wrapper on top of importctl that would hack this behavior.

The systemd version you checked that didn't have the feature you are asking for

256~rc1

[bluca]

Sounds reasonable, we have the same behaviour in other tools, could you send a PR?