Over the summer, I'm looking into depositing Tor relays (not exit nodes!) with my friends in family in the form of something that they can plug in and forget about. I've read about the Rasberry Pi being an excellent platform for a low-power relay, but I'm afraid I don't know how to set it up so that it updates itself. Is there a guide on setting up independent, low-power easily monitored Tor relays?
Raspberry Pi is good for this. Add the repository, install Tor and configure.
You can clone the memory-card and put it in a new one for easy setup of multiple Raspberry Pi's.
For updates just make a
cron job that updates packages every X day. Then the Pi will pull the latest updates without the user having to do anything.
If you are using Raspbian/Debian, you may want to investigate the cron-apt package, instead of making a custom
cron job for updates.
I've been running a Tor relay and hidden service website for over a year on a Pi. one thing I recommend is that you buy an SD card twice the size you need for the Pi image. The empty space is used for wear leveling of the flash memory.