[systemd-devel] Starting a unit on resume from suspend/hibernate

[Dimitrios Apostolou]

On Thu, 2 Apr 2015, Andrei Borzenkov wrote:

> В Thu, 2 Apr 2015 19:34:55 +0200 (CEST)
> Dimitrios Apostolou <jimis at gmx.net> пишет:
>
>> On Thu, 2 Apr 2015, Dimitrios Apostolou wrote:
>>
>>> On Thu, 2 Apr 2015, Andrei Borzenkov wrote:
>>>
>>>>  В Thu, 2 Apr 2015 18:43:40 +0200 (CEST)
>>>>  Dimitrios Apostolou <jimis at gmx.net> пишет:
>>>>
>>>>>  Conflicts=sleep.target
>>>>>  WantedBy=multi-user.target sleep.target
>>>>
>>>>  These are mutually conflicting. One one hand Conflicts says to stop your
>>>>  unit when sleep.target gets started, on the other hand WantedBy says to
>>>>  start your unit when sleep.target gets started. Only one can win.
>>>
>>> Indeed, but I was assuming that combined with "after" they could co-exist,
>>> starting the unit after the dependency has started and stopped. And if it was
>>> a problem I would expect a message, since it's easy to detect.
>>>
>>> Anyway even removing the Conflicts line does not help. "systemctl enable"
>>> still does not install the symlink, and manually installing the symlink does
>>> not change anything.
>>
>> Hmmm I did some more trials with the "conflicts" line commented out. While
>> just listing "sleep.target" didn't work, the following was successful and
>> the unit starts after resuming:
>>
>
> How is it stopped then? It is apparently started on boot (WantedBy
> multi-user.target) and there is no conflicts so it is never stopped.

Sorry I wasn't clear. The service was manually stopped before 
suspend/resume. Ofcourse I wouldn't expect the service to stop, since I 
removed the "conflicts" line, so this alone can't be the complete 
solution for my case.

>
>> After=sleep.target suspend.target hibernate.target hybrid-sleep.target
>
> Yes, this works due to the way it is implemented. Not sure if it is
> committed functionality though.
>
>> WantedBy=multi-user.target sleep.target suspend.target hibernate.target hybrid-sleep.target
>>
>
> This is redundant, WantedBy=sleep.target should be enough.
>
>> In addition "systemctl disable/enable" didn't create the symlinks, I had
>> to properly add them. Maybe it's a bug?
>
> bor at opensuse:~/src/dmraid/1.0.0.rc16-3/dmraid> systemctl status test.servicetest.service - Test
>   Loaded: loaded (/run/systemd/system/test.service; disabled)
>   Active: inactive (dead)
>
> bor at opensuse:~/src/dmraid/1.0.0.rc16-3/dmraid> sudo systemctl enable test.service
> bor at opensuse:~/src/dmraid/1.0.0.rc16-3/dmraid> systemctl status test.servicetest.service - Test
>   Loaded: loaded (/run/systemd/system/test.service; enabled)
>   Active: inactive (dead)
>
> bor at opensuse:~/src/dmraid/1.0.0.rc16-3/dmraid> ll /etc/systemd/system/sleep.target.wants/
> итого 0
> lrwxrwxrwx 1 root root 32 апр  2 20:36 test.service -> /run/systemd/system/test.service
> bor at opensuse:~/src/dmraid/1.0.0.rc16-3/dmraid>
>
>
>>
>>
>> Thanks,
>> Dimitris
>
>