Each time I’ve deployed a Pi, I’ve added a DS18B20 temperature sensor to it; a cron launched Python script logs temperatures to a relational database, which I can then monitor (though I still use MQTT to get the data into HA, as the integration is simpler).
The one Pi I’m not monitoring is the HAOS (not Docker) Pi.
I get that HA has depreciated direct GPIO support, but they are active on the Pi and if I SSH in I can see the sensors id in /sys/bus/w1/devices. My HA Pi runs MariaDB for logging, I’m just not sure where to run a script to access the reading and how to trigger it outside the HA environment.