[systemd-devel] Systemd --session instance?

[Zbigniew Jędrzejewski-Szmek]

On Sat, Apr 22, 2017 at 02:07:49PM +0000, Benno Fünfstück wrote:
> Hello list,
> 
> currenty, systemd runs a system instance and a per-user one. However,
> sometimes it would be nice to have a per-session instance, for example for
> users of lightweight desktop environments that don't have their own service
> manager. Then you could use systemd to spawn things like panels or desktop
> notification daemons etc. Would it be possible to add such a thing, even if
> it may require some work? Or are there any fundamental problems with it?

It would require a fundamental amount of work. We (people developing
systemd, large graphical environments, dbus, ...) to move towards user-sessions,
and limit support to one graphical session per user. The thinking is that
one graphical session is enough for one user.

In principle you could still have a single systemd --user instance,
and e.g. start various services multiple times using templating
(terminal-daemon at .service, file-manager at .service, etc). This isn't too
hard to get working in a limited scope, but making it work in general
is hard, and would require a lot of support from various
programs. Your use case would be neat, but also a bit fringe, and it's
complicated enough to get graphical envs working with one session per
user.

Zbyszek