[systemd-devel] Monitoring whether all dependencies of a target are active

[Chris Morin]

>
> We just migrated to Systemd and we love it!
>
> Now I'm looking for a way to monitor if all the "important units" of my
> system are running or not.
> My plan is to create a target that "wants" all those important units.
> Then I'll just need to check that the dependencies of those units
> are active. If there are non-active units for 5 minutes or more
> I'll trigger an alert.
>
> Do you think that's a good way to check the healthiness of my units, or is
> there a better way?

You might want to use the OnFailure option in the unit files you want
to monitor instead instead of using a target and wants.
https://www.freedesktop.org/software/systemd/man/systemd.unit.html#OnFailure=

Whatever action would have been taken by your polling script could
just be done in the service specified in the OnFailure option.