Oh oh, can you show me your chimera.nix file? I'm having trouble finding a correct incantation how to do that and how to use it in an /etc/configuration.nix for NixOS :(
Here's my repo: https://github.com/colemickens/nixcfg/
Start in {configurations,machines}/chimera.nix and explore outward from there ;).
EDIT: I forgot, I decommissioned 'chimera' because computers are terrible. `xeep` is probably a better example of what you're looking for. `azera` is an Azure VM that runs the services `chimera` used to host.
Sorry if the repos a bit messy. I don't practice good git hygiene there. Feel free to ping me on the nix IRC rooms or email me. I love NixOS and enjoy evangelizing cool tech.