NixOS Facter aims to be an alternative to projects such as NixOS Hardware and nixos-generate-config. It solves the problem of bootstrapping NixOS configurations by deferring decisions about hardware and other aspects of the target platform to NixOS modules.
I had a frustrating issue yesterday. I had removed drives, and forgot to edit my hardware config, so it kept failing to boot and would go into emergency mode, which I didn’t have an internet connection in so I couldn’t rebuild.
I ended up having to figure out which drive was missing in order to get it to boot (long story, I had to go through a stack of 4tb drives to find the right one).
How could I have fixed this issue had the drive not been available? Manually bringing up the network stack, I suppose?