All openHAB Bindings Fail
I installed openHAB on my rPi using the instructions on the openHAB site, but I could not get any bindings to work. At first I thought it was a problem specific to the Insteon PLM binding and my (older/pre-2014) Insteon Hub. I was able to get the Twitter action working, but it wasn't until I couldn't get the WOL (Wake-on-LAN) binding working that I realized that it was probably not specific to the Insteon connection. What made it especially troubling was that I wasn't getting any kind of logging at all -- and, critically, no errors to analyze. Repeated and extensive searching online offered few clues.
The core of the problem seems to be that the installation instructions leave everything owned by root. Ownership needs to be changed so that things are owned by openhab. I finally paid attention to the ownership thanks to this article by James Bruce; bindings started working for me after I used the following commands:
sudo chown -hR openhab:openhab /etc/openhab sudo chown -hR openhab:openhab /usr/share/openhab
This also means that I now have log messages to analyze, which is useful, because the Insteon connection is still not working even though the binding itself is finally activating. There seems to be some issue with properly identifying devices, but that's another problem for another day.