This was a proof of concept implementation from 2016, to let managed Linux workstations sleep under some conditions.
Due to the current state of things: https://www.energieschweiz.ch/programme/nicht-verschwenden/startseite/
The project is published here, maybe if it is of some use to you.
The details:
You will need the package pm-utils from your distribution, which is
a command line interface to https://www.kernel.org/doc/Documentation/power/.
See what your system supports with cat /sys/power/state.
Some conditions are checked if it is feasible to let the computer sleep.
/etc/pm/sleep.d/99-energysaving
First check, if the machine is allowed to go to sleep, must be listed
in /etc/sleeper.
Following conditions abort the suspend mode
- if remote mounts are active (showmount -a)
- if cronjobs for the user or root are set up
- if any remote user is logged in On success a note is sent to our Hobbit / Xymon Monitoring (this can be adapted to whatever monitoring system you use) system.
More or less, this:
cp sleeper /etc
cp 99-energysaving /etc/pm/sleep.d
cat cron >> /var/spool/cron/crontabs/root
Please consult /var/log/pm-*.log