[systemd-devel] unable to attach pid to service delegated directory in unified mode after restart

[Michal Koutný]

On Wed, Mar 16, 2022 at 05:06:28PM +0100, Lennart Poettering <lennart at poettering.net> wrote:
> > That owner would be a process -- bang, you created a service with
> > delegation or a scope with "keepalive" process.
> 
> can't parse this.

That was meant as a humorous proof by contradiction that delegation on
slices is unnecessary. Nvm.

> > (The above is slightly misleading) there could be an alternative of
> > something like RemainAfterExit=yes for scopes, i.e. such scopes would
> > not be stopped after last process exiting (but systemd would still be in
> > charge of cleaning the cgroup after explicit stop request and that'd
> > also mark the scope as truly stopped).
> 
> Yeah, I'd be fine with adding RemainAfterExit= to scope units

Felip, I'd happily review such a PR ;-)


> > Such a recycled scope would only be useful via
> > org.freedesktop.systemd1.Manager.AttachProcessesToUnit().
> 
> Well, if delegation is on, then people don#t really have to use our
> API, they can just do that themselves.

True, in the unified mode it should be safe doing manually.
I was worried about migrating e.g. MainPID of a service into this scope
but PID1 should handle that AFAICS. Also since this has to be performed
by the privileged user (scopes are root's), the manual migration works.

Michal