Hi ralfkrause , apologies for the late reply, for some reason I didn't get a notification about your message. I will look in to why and check my settings are ok.
In short, nothing needs to be installed on the Raspberry Pi, the Moodle-App is all self contained. Click the
deploy button and it will take you to a page where you can download an image to flash to your device, which includes the Operating System (Balena OS) and the app. Once you have flashed it to the device, make sure your Raspberry Pi is plugged in to the Ethernet so it has internet access and then it will download and start Moodle. You may need to set the DEVICE_HOSTNAME in the dashboard so it knows the URL you use to access it, for example DEVICE_HOSTNAME=your-device for http://your-device.local.
It's a proof of concept really, to see if someone might want to work on it. There are additional things we could add such as WiFi which is already built as a block so we can add it in with a click (https://hub.balena.io/organizations/balenablocks/blocks/wifi-connect).
We could also set a default hostname on the device (https://hub.balena.io/organizations/g_tomas_migone1/blocks/hostname-aarch64) and preload the images through GitHub so that they can be downloaded directly from a website or GitHub releases (https://github.com/balena-community/community-cli-action).
With these features dropped in it would be as simple as flashing the image to the device (OS and app all included) and then starting it. It would start on something like http://moodlebox.local and wifi hotspot would be active immediately. Then it would join the fleet that is controlled through the Balena dashboard as soon as it comes online (assuming someone wants to connect it to their local network through the wifi hotspot) and check for and install updates.
Then however, comes the running and maintaining of Moodle and all its PhP and database configurations. I think I got it about right, but really this forum is the place where the experience is.