Re: [systemd-devel] PAMName=login, systemctl stop
On 03.07.2023 14:17, Lennart Poettering wrote: > logind's session ID you'll find in the $XDG_SESSION_ID env var. > > you can use this to kill your own session: > > loginctl kill-session $XDG_SESSION_ID > > if you want to know which systemd unit your process belongs to use: > > ps --pid $$ -o unit= I was struggling with the same problem a few months ago and came up with (bear up): ExecStop=/bin/sh -c "loginctl kill-session --signal SIGTERM `systemctl -n1 -o export status \"$MAINPID\" | grep _SYSTEMD_SESSION | cut -f2 -d=`" ExecStopPost=/bin/sh -c "loginctl terminate-session `systemctl -n1 -o export status \"$MAINPID\" | grep _SYSTEMD_SESSION | cut -f2 -d=`" This worked well (I'm not using it though, it was only some test setup), but I was wondering if systemd couldn't help somehow, e.g. exposing $_SYSTEMD_SESSION variable directly; ExecStop=loginctl kill-session --signal SIGTERM $_SYSTEMD_SESSION doesn't look so scary anymore. Another idea was to ask for new feature: KillMode=session which could do exactly this. -- Tomasz Pala
Re: [systemd-devel] PAMName=login, systemctl stop
On Mo, 03.07.23 15:21, Andrei Borzenkov (arvidj...@gmail.com) wrote: > On 03.07.2023 14:17, Lennart Poettering wrote: > > On Mo, 03.07.23 10:58, Valentijn Sessink (valent...@sessink.nl) wrote: > > > > > Now my remaining question is probably so very basic, that you sort of > > > missed > > > it: my "session" is started from a script and so I'm probably able to stop > > > all services in the session from within this script - if I knew how to > > > find > > > "it": "it" being "the thing to stop", i.e. "my own session" or something > > > like that. I.e. the script should kill itself and all its children. > > > > logind's session ID you'll find in the $XDG_SESSION_ID env var. > > > > you can use this to kill your own session: > > > > loginctl kill-session $XDG_SESSION_ID > > > > It is not defined here on Ubuntu 22.04 with GNOME 42 that is using systemd > for session management. It *is* defined in GDM session worker, but as actual > session processes are not children of it (they are started by systemd) this > variable is not inherited. GNOME doesn#t run in a logind session, but as services off the user@.service instead, i.e. in session context rather than login session context. Hence it doesn't have XDG_SESSION_ID set. This is different if you use PAMName= for arbitrary services. That means you get a proper session allocated, and hence also XDG_SESSION_ID set. Lennart -- Lennart Poettering, Berlin
Re: [systemd-devel] PAMName=login, systemctl stop
On 03.07.2023 14:17, Lennart Poettering wrote: On Mo, 03.07.23 10:58, Valentijn Sessink (valent...@sessink.nl) wrote: Now my remaining question is probably so very basic, that you sort of missed it: my "session" is started from a script and so I'm probably able to stop all services in the session from within this script - if I knew how to find "it": "it" being "the thing to stop", i.e. "my own session" or something like that. I.e. the script should kill itself and all its children. logind's session ID you'll find in the $XDG_SESSION_ID env var. you can use this to kill your own session: loginctl kill-session $XDG_SESSION_ID It is not defined here on Ubuntu 22.04 with GNOME 42 that is using systemd for session management. It *is* defined in GDM session worker, but as actual session processes are not children of it (they are started by systemd) this variable is not inherited. if you want to know which systemd unit your process belongs to use: ps --pid $$ -o unit= Lennart -- Lennart Poettering, Berlin
Re: [systemd-devel] PAMName=login, systemctl stop
On Mo, 03.07.23 10:58, Valentijn Sessink (valent...@sessink.nl) wrote: > Now my remaining question is probably so very basic, that you sort of missed > it: my "session" is started from a script and so I'm probably able to stop > all services in the session from within this script - if I knew how to find > "it": "it" being "the thing to stop", i.e. "my own session" or something > like that. I.e. the script should kill itself and all its children. logind's session ID you'll find in the $XDG_SESSION_ID env var. you can use this to kill your own session: loginctl kill-session $XDG_SESSION_ID if you want to know which systemd unit your process belongs to use: ps --pid $$ -o unit= Lennart -- Lennart Poettering, Berlin
Re: [systemd-devel] PAMName=login, systemctl stop
Hi Lennart, hi list, On 03-07-2023 10:47, Lennart Poettering wrote: I can get the CGroup and session scope with "systemctl status "; but I still can't figure out what to stop then. So how can I finish this "spawned off" session - the one that started from a "PAMName=login" option in the service file? I am not sure I grok your question. From your answer I'd guess you did. But we do not provide a way currently to associate session scope units with the service units they have been created by. There's no nice way to go from one to ther other. OK, that's important information. Now my remaining question is probably so very basic, that you sort of missed it: my "session" is started from a script and so I'm probably able to stop all services in the session from within this script - if I knew how to find "it": "it" being "the thing to stop", i.e. "my own session" or something like that. I.e. the script should kill itself and all its children. Would that be possible? I simply don't know how to "find my own session and kill it" from within my own session - and I wouldn't know how to stop it either. To rephrase: how should a session commit suicide if it really wants to? ;-) Does that help? (Or is the answer "no you can't - seek help" ;-) Best regards, Valentijn
Re: [systemd-devel] PAMName=login, systemctl stop
On Fr, 30.06.23 15:11, Valentijn Sessink (valent...@sessink.nl) wrote: > Hi, > > On 28-06-2023 18:04, Lennart Poettering wrote: > > > "PAMName=login", then starts a script and a few (old X11 related) > > > programs. > [...]>> Is there a way to amend the service file to stop these children? > > Not really, from systemd's PoV they are part of the login session, not > > the original service anymore. > > I have tried to get my head around this but I couldn't find how to proceed, > i.e. how to kill of the session. > > I can get the CGroup and session scope with "systemctl status "; > but I still can't figure out what to stop then. So how can I finish this > "spawned off" session - the one that started from a "PAMName=login" option > in the service file? I am not sure I grok your question. But we do not provide a way currently to associate session scope units with the service units they have been created by. There's no nice way to go from one to ther other. You can terminate service units via "systemctl stop", and you can terminate session scope units the same way, but there's no mechanism to relate one to the other. And I am not sure that's even unconditionally desirable, because typically scopes and the services they are spawned from might have different lifecycles, i.e. the sessions are fine with surviving if the invoking service dies. Lennart -- Lennart Poettering, Berlin
Re: [systemd-devel] PAMName=login, systemctl stop
Hi, On 28-06-2023 18:04, Lennart Poettering wrote: "PAMName=login", then starts a script and a few (old X11 related) programs. [...]>> Is there a way to amend the service file to stop these children? Not really, from systemd's PoV they are part of the login session, not the original service anymore. I have tried to get my head around this but I couldn't find how to proceed, i.e. how to kill of the session. I can get the CGroup and session scope with "systemctl status "; but I still can't figure out what to stop then. So how can I finish this "spawned off" session - the one that started from a "PAMName=login" option in the service file? Sorry if it's a dumb question. Any links to documentation are fine, too. Best regards, Valentijn -- Durgerdamstraat 29, 1507 JL Zaandam; telefoon 075-7100071
Re: [systemd-devel] PAMName=login, systemctl stop
On Do, 22.06.23 16:22, Valentijn Sessink (valent...@sessink.nl) wrote: > Hello list, > > I have a rather simple service file that sets up a user session with > "PAMName=login", then starts a script and a few (old X11 related) programs. > Starting it is easy, but stopping the service will send SIGTERM only to the > main process, because "Any child processes of that process will however be > associated with the session scope unit only" - as per man systemd.exec(5). > > Is there a way to amend the service file to stop these children? Not really, from systemd's PoV they are part of the login session, not the original service anymore. You can't have it both ways: be a session and a service. In system it's either/or. Lennart -- Lennart Poettering, Berlin
