Run the SOCI snapshotter with systemd

[ollypom]

What is the problem you're trying to solve?.
Today we are running the SOCI snapshotter as a background process. Could we switch to running the SOCI snapshotter as a systemd service? Among many other benefits, it would help centralize soci snapshotter logs into journald. The SOCI snapshotter project already provides an example systemd file.

We also are already running the stargz snapshotter with systemd in Finch (Another outstanding question here is should we be? considering we don't expose stargz in the Finch configuration file).

$ sudo systemctl status stargz-snapshotter
● stargz-snapshotter.service - stargz snapshotter
     Loaded: loaded (/usr/local/lib/systemd/system/stargz-snapshotter.service; enabled; preset: disabled)
    Drop-In: /usr/lib/systemd/system/service.d
             └─10-timeout-abort.conf
     Active: active (running) since Thu 2023-10-26 10:30:09 UTC; 16min ago

Describe the feature you'd like
Could we switch to running the SOCI snapshotter as a systemd service?

Additional context
Add any other context or screenshots about the feature request here.

[ginglis13]

@ollypom starting soci as a normal process on boot proved to be an issue with the Windows implementation of Finch, so we opted to pivot to starting soci as a systemd service as part of that effort.

See

finch/pkg/config/lima_config_applier.go

Lines 39 to 46 in 998989a

	# install as a systemd service
	curl --retry 2 --retry-max-time 120 -OL "%s"
	mv soci-snapshotter.service /usr/local/lib/systemd/system/
	ln -s /usr/local/lib/systemd/system/soci-snapshotter.service /etc/systemd/system/multi-user.target.wants/
	restorecon -v /usr/local/lib/systemd/system/soci-snapshotter.service
	systemctl daemon-reload
	sudo systemctl add-requires soci-snapshotter.service containerd.service
	systemctl enable --now soci-snapshotter

which is included in #649

We can opt to either port that commit over to main ASAP, or wait for the release of Finch that includes Windows support.

[pendo324]

Fixed by #667.