My NixOS Config

A simple NixOS flake setup tracked by git.

Build

To build a system, first cd into this repo at the root level where the flake.nix is. Hosts should be documented in the hosts directory. Specify a host to build with a 'sharp' and run the following.

# Building seanbox_4080super system as example

sudo nixos-rebuild switch --flake $(pwd)#seanbox_4080super

Creating a new User

To make a new user, create a new nix module under ./users/my_new_user with entry point default.nix. Your user should be managed by home-manager. Add home-manager as a Nix Module into your host config and import your user module into home-manager users. Follow the existing code as a guide in flake.nix.

Creating a new Host

To create a new host, first install NixOS on the new machine.

Once the initial /etc/nixos/ has been generated, create a new directory in this repo under hosts and move the auto generated nix config files into it. Change the configuration.nix file to default.nix. A file named default.nix indicates an entrypoint into a nix module.

mkdir -p ./hosts/my-new-host
sudo mv /etc/nixos/hardware-configuration.nix ./hosts/my-new-host/hardware-configuration.nix
sudo mv /etc/nixos/configuration.nix ./hosts/my-new-host/default.nix
sudo chown -R $(id -un):$(id -gn) ./hosts/my-new-host

Remove the default location of your system config. From this point on, rebuilding the system will always require specifying a host from this repo.

sudo rmdir /etc/nixos

Now you need to add the new host as a module in the flake.nix. Follow along with what's already in the file. Your new host should look something like this...

  #...

  outputs = { self, nixpkgs, home-manager }: {
    nixosConfigurations = {

      seanbox_4080super = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          # ...
        ];
      };

      my_new_host = nixpkgs.lib.nixosSystem {
        system = "<YOUR SYSTEM ARCH HERE>";
        modules = [
          ./hosts/my_new_host

          # Additional modules such as home-manager here
          # If you're adding a user, import from a module under ./users/
        ];
      };

      # Add additional host machine configs here

    };
  };

Building with a flake requires files to be added in git. Don't commit changes yet.

git add flake.nix ./hosts/my-new-host

Now you can rebuild the system. You can make whatever changes you need to produce the proper state for your system. After updating any of your nix config files, you will need to git add the changes before rebuilding. Once your system state output is correct, git commit the changes to secure the state. With git, if something goes wrong, you can always checkout a previous system config and restore a previous state.

sudo nixos-rebuild switch --flake .#my_new_host

# Update system packages and config as needed, git add, rebuild, repeat...

git commit

# Use git checkout/revert to rebuild any previous state you've committed