Comment 11 for bug 1732703

It is correct, in general, to check for /run/systemd/system to detect if systemd manages pid 1.

Imho deputy systemd (used by snapd, on trusty, with xenial-lts kernel) should not have been creating that, however I fear that without that directory snapd and snaps therein may get confused (in classic confinment).

It is true that trusty only uses upstart as pid1 with no other options; and any system systemd jobs are inert (deputy systemd only looks for deputy things).

Note that although xenial ships both upstart & systemd; only systemd is supported as pid1 on all form-factors. (upstart as pid1 is only supported on xenial ubuntu touch product, which is now end-of-life).

Possibly we could create one more directory e.g. /run/dsystemd/system or some such, which maas can check for to destinguish "systemd or deputy-systemd".

However, checking /sbin/init like done in the proposed merge proposal is very adequate for maas needs, and should yield correct results. As far as I can tell, since on xenial either upstart-sysv or systemd-sysv may provide /sbin/init, with systemd-sysv being the default everywhere. (upstart-sysv on xenial is for ubuntu touch only).

Ideally, I do not want to touch deputy systemd uploads.