On Thu, Feb 6, 2025 at 10:29 AM Dluhosch, Michael < michael.dluho...@airbus.com> wrote:
> Hello, > > > I want a service which executes 'startFoo.sh' exactly like a user 'Foo' > would experience it. This is my current approach: > > [Service] > ExecStart=/usr/bin/startFoo.sh > > User=Foo > > PAMName=login > > > And it seems to work just fine. But I can't figure out how to stop this > service and all of its childs in a clean way. According to the systemd.exec > documentation this service will start a 'session scope' CGroup but it does > not mention how to stop this when the service stops. So far I found this > workaround: > > I add a > > ExecStop=/usr/bin/stopFoo.sh > > to the main service which does that: > > #!/bin/bash > systemctl stop $(systemctl status $(pidof > <anyProcessNameInsideTheChildCGroup>) | grep user.*slice | grep -o > session.*scope) > > > Is there a clean solution to accomplish something like this? > No; part of "exactly like a user" literally means that it gets moved by PAM outside of the regular service tracking, so it will be ugly no matter what. But reading from /proc/$PID/cgroup is a much more script-friendly method than "systemctl status", even if it doesn't directly give you a unit name... but currently you're grepping the cgroup path anyway, so you could do $(basename "$(</proc/self/cgroup)") to get the needed result. So If you really have to make it run that way, then have the startFoo.sh script record its own cgroup (from /proc/self/cgroup) in a file – much like you'd use a pidfile – and then have stopFoo.sh stop the corresponding unit. But more generally, I'd really prefer narrowing down that "exactly like a user". Where does that requirement come from? Does the app need to pop up on the user's desktop, or something like that? (Is it a standard desktop or some kind of embedded system with autologon-to-GUI?) In many cases, running it as a *user* service (systemctl --user start...) would be a better approach since it lets the contents of the service stay within their original "service" cgroup and be tracked accordingly. -- Mantas Mikulėnas
