I’ve just set up a new NAS/Web/whatever server for my apartment and feel it unnecessary to run unrar on my regular desktop (which leads to a lot of delay as the stream goes NAS -> Workstation -> NAS). So I wrote a quick python script that will work to send an unrar command through a ssh connection to the NAS server which then executes the command on the server which leads to a much quicker unraring of the files. This script however requires that the mounted volumes are located in the same base directory on both computers (for example, I got my archive mounted on /mnt/archive on my NAS, I then have to mount the samba volume on my workstation to /mnt/archive). It contains a quick installation script and all python scripts requires python 3+ (as I have abandoned python < 3 for easier programming).
The downloadable zip file contains a README file and a configuration script for easy installation.