I think there needs to be a balance between how long it takes this little machine to boot and long term maintenance. 15-20 minutes or more to reach a usable state for a thermostat just feels unacceptable to me. I feel like it shouldn’t take that long but I don’t have enough experience yet to see how much we can cut off of it. That’s the main reason I’d try DietPi.
Given that you don’t really have a way to update the OS after it’s deployed (Mosquitto and openHAB will both upgrade to the latest version if you run
apt upgrade it doesn’t really matter if there is LTS or not. Once deployed it has to remain static.
I don’t think that’s the right answer either really so maybe a Buster Lite with a script to strip out a bunch of stuff would be a better approach?
As of Mosquitto 1.5.4 it comes with websockets by default, no need to rebuild. The latest version of Mosquitto is 1.6.8.
I’ll have to look into Turnkey. Their github indicates they require Stretch. I’ll have to research whether there is a reason it can’t support Buster or their readme hasn’t been updated.
One concrete recommendation I’d make is to change the image so that openHAB and Mosquitto and anything else that needs to remain untouched get’s installed as a specific version (e.g.
apt install openhab=2.4.0-1). That way running an apt upgrade won’t upgrade OH and those other apps too. Then we the user can get security and other OS updates without breaking anything.
If we had more RAM I’d push containers but there just isn’t enough RAM on the RPi 0 to consider that.