I want to run `nixos-rebuild switch` inside of a docker container

Help
1

I want to know if I can get a docker image with NixOS on it

I want something like

FROM nixos/nixos

COPY configuration.nix /etc/nixos/configuration.nix

RUN nixos-rebuild switch

CMD ["echo", "maybe just run nginx"]
2

nixos-generators can help you build a docker image.

3

I literally just finished this today: GitHub - TRPB/docker-nixos: Run an arbitrary NixOS configuration in a docker container

You can provide an arbitrary configuration.nix or flake and it will be built and activated via nixos-rebuild switch on startup.

The nixos/nixos base image is not actually NixOS, it contains the package manager but not the full OS. Probably because running systemd in docker is a bit of a pain (see the limitation section in the readme on the repo)