nixos-config VS nix-config

All the resources mentioned in other comments are pretty good, but mostly they are unofficial. The official NixOS wiki is very outdated and unmaintained. You will have better luck reading other people’s configurations, nixpkgs source code and GitHub issues. For the nix language the official wiki is a nice reference https://nixos.org/manual/nix/stable/language/index.html. This configuration is a great starting point https://github.com/Misterio77/nix-config for learning by example. It covers most of what you may need, although bootstrapping your own config is quite rough. You may want to take a look at https://github.com/Misterio77/nix-starter-configs. It’s very basic and should be simple to understand and improve.

Yes. E.g. some guy's config with 6 different machines[1]: multiple desktops, laptops, servers, a Raspberry Pi, and a VPS. That's a rather advanced use of Nix for configuration, but definitely shows what it's capable of.

[1] https://github.com/Misterio77/nix-config

https://github.com/Misterio77/nix-config/blob/main/hosts/celaeno/services/hydra/lib/release-host-branch.nix https://github.com/Misterio77/nix-config/blob/main/hosts/celaeno/services/hydra/default.nix#L39

Implementation: https://github.com/Misterio77/nix-config/blob/main/pkgs/fetch-packwiz-pack/default.nix

the one i reference all the time is https://github.com/Misterio77/nix-config

I believe Misterio77's does use it in his config.

I reuse the same btrfs logic on all my computers, including a RPi: https://github.com/Misterio77/nix-config/blob/main/hosts/common/btrfs-optin-persistence.nix