reboot: Add a simple plugin to reboot a machine

[neverpanic]

Assumes systemd, beacuse it uses systemctl to wait for the boot to complete.

[t184256]

reboot: Add a simple plugin to reboot a machine

Good idea, this is a common scenario.

Assumes systemd, beacuse it uses systemctl to wait for the boot to complete.

Yeah, since this the step is distro-specific, this should be made more flexible with hooks. See, for example, how timesync decouples this.

[neverpanic]

Untested with os.alpine, because that seems to be broken. Also, os.alpine does not define m.login(), so the reboot action is also broken because of that. I may eventually fix the os.alpine definition, but quite a few things seem to have changed in alpine land, so it isn't trivial.

[t184256]

Thank you, doubly so for patience with my review.