coreos/go-systemd

Simplified interface to monitor job completion status

onitake opened this issue · 1 comments

onitake commented

It looks like there is currently no easy way to wait for start/stop unit job completion.
The job ID returned by dbus.Conn.StartUnit seems to be quite useless.

I see two possibilities by means of what's provided in go-systemd:

  1. Register for notifications with dbus.Conn.SubscribeUnitsCustom and filter out the desired unit and target state.
  2. Poll for unit status with dbug.Conn.ListUnitsByNames.

This blog even describes a low-level approach:
https://jonathangold.ca/blog/waiting-for-systemd-job-to-complete/

It would be much more helpful if the jobid returned by StartUnit/StopUnit could be used to check or wait for completion, but it seems like such a feature is not provided by SystemD. Would it be possible to provide some sort of Wait/Join/Check function built on top of the functions above to determine when a job completes?

onitake commented

My bad, I completely overlooked the channel you can pass to StartUnit et al.
I still don't quite see what the job ID is for, but the channel should be sufficient for getting the job status.