[systemd-devel] How to add a unit path to systemd?

[Lennart Poettering]

On Do, 09.08.18 10:20, Daniel Wang (wonderfly at google.com) wrote:

> Hi,
> 
> I want to append to systemd's unit search path a directory on my OEM
> partition, which is mounted  by a .mount unit, at /usr/share/. I will be
> putting unit files in that partition, some of which I want to run before
> default.target. Is it possible to do so without a systemctl
> daemon-reload?

/usr/share appears like a surprising place for this…

In general, in systemd the assumption is that unit files are available
during earliest boot, so that the initial transaction can be
calculated with all units taken into account. Hence a relatively clean
solution might be to mount your partition already in the initrd, so
that systemd sees it in place already.

Alternatively, you actually can issue daemon reload during the boot
process, but you'd have to enqueue the new units appearing explicitly,
i.e. trigger a second transaction because what isn't there won't be
considered in the initial one.

Lennart

-- 
Lennart Poettering, Red Hat