We would like to use maas in an airgapped environment. So far we have uploaded our custom RHEL image to maas and are able to PXE boot into the comissioning ubuntu image, but it failed when trying to reach archive.ubuntu.com. When reading through the documentation it sounds like it is suggesting to mirror the entire archive.ubuntu.com repo, but since we are going to be using RHEL, we only need to mirror the minimum packages the comissioning image needs. At least thats way we currently understand it to work. Is there a list of the specific packages/snaps needed during comissioning?
If you want to have the list of archives you could setup a test environment with a MAAS installation, a squid proxy and configure MAAS to use it. Then you can commission a machine and extract the squid logs to see what packages were requested by the machine