Control fanspeed by HDD temperature

Hello,
on my NAS running latest OMV the temperature is currently controlled by the CPU temperature - not a very good solution for the NAS as most of the heat is generated by the 4 harddrives.
After playing around with pwmconfig I am able to read and set the fanspeed. But how is the best approach to automate this in OMV?
There is a project to achieve this: https://github.com/desbma/hddfancontrol
But unfortunately the python version in OMV is too old.
Any ideas?