Hello!
I want to remotely shut down my Raspberry Pi over lan when i power off my computer. Authentication is not an issue. I've tried serveral entries and searched across the web but i'm out of ideas.

It works fine when i start this service manually:

but i haven't found out what dependencies it needs to be enabled in order to be executed before the network is shut down.

Further criteria that the service would need to meet:

*) it should only be executed at shutdown and not at reboot.

*) if possible it should be executed early in the shutdown-process.
Scince the RaspberryPi is powered via the PCs usb it's power supply
could be cut off before it has completely shut down. Is there a way to
make the system idle a few seconds before halt to achieve this?

Thank you.

Take a look at man shutdown.

Not tested...
This should be the first service run at shutdown. Not sure how to add a delay but should be doable if necessary.

Thanks. Doesn't work, i've tried this except the ExecStart=/bin/true. It does work when i manually stop the service though.

yes but it should ideally work both over gui as well as cli.

Did you enable the service?

Yes i did. I had to restart a few times and now it seems to be working partially. I have the following results (using debian8/kde plasma):

*) it works when i shutdown/reboot over cli
*) it doesn't work when i use the poweroff options in the kde application launcher
*) the timespan for the Raspberry Pi to be shut down seems to be right so no idle time necessary.

i was just wondering if a different approach makes sense: instead of running a unit on boot is it possible to write one that starts exactly at shutdown (and thus not on reboot)?

Thank you again.

Not sure why it would only work via the command line. I would not expect different behavior but you could try these changes. Shutdown scripts do not run at boot.