As I understand it, in order for this OS image to work fully out of the box we will also need to create a custom gadget snap which contains assertions to auto-connect interfaces (currently network-manager and system-observe but I expect there to be more) and enable hotplug support. We may also eventually want to configure some settings on the gateway snap such as the HTTP/HTTPS ports the gateway's HTTP server binds to, if that's not just handled via iptables as with the Raspberry Pi image.

Since custom gadget snaps are not allowed in the public Snap Store, this gadget snap will need to use "dangerous mode" and will have to be sideloaded onto the custom image, until such a time as a signed version can be submitted to a dedicated app store which can offer OTA updates.

@ogra1 It would be helpful for me if you could do a first pass on creating two gadget.yaml files which provide the above - one for Intel NUC and one for Raspberry Pi - to demonstrate how to do it.