the-argus / nixsys

My NixOS system configuration.

Nix system configuration flake

This repository describes the setup of both my laptop and PC. It's a relatively large flake because I am very committed to reproducibility. The only things in my setup that don't exactly match what you will get from building this repository are some browser extensions, installed flatpaks, and my wallpapers.

Usage

To apply or update, install nix-direnv-flakes: nix shell nixpkgs#nix-direnv-flakes. Then run direnv allow to enter the environment. Finally, run "rebuild" or "update", respectively.

You can find configurations for different machines inside of the hosts/ directory. In order to build the configurations for different hosts instead of the default, run rebuild laptop or rebuild pc.

lib/ directory and finalizeSettings function

Each host (both laptop and PC) have different configurations for nixpkgs. Unlike configuration options such as environment.systemPackages, it is not possible to set these with modules. Therefore, each host has some settings (found in hosts/[hostname]/default.nix) which are imported and used in order to import nixpkgs. Here is a snippet of code from the flake.nix, for example:

{
  outputs = let
    hosts = {
      laptop = import ./hosts/laptop {
        inherit nixpkgs;
        hostname = "evil";
      };
      pc = import ./hosts/pc {
        inherit nixpkgs;
        hostname = "mutant";
      };
    };
  in
  {
    nixosConfigurations = {
      laptop = self.createNixosConfiguration hosts.laptop;
    };
    
    packages.${defaultGlobalSettings.system} = {
      myPackages =
        (finalizeSettings defaultGlobalSettings).pkgs.callPackage ./packages {};
    };
  };
}

On the last line, you can see that (finalizeSettings defaultGlobalSettings) returns a set which includes pkgs, which is the finished and imported nixpkgs.

Making your own host: available settings

First, copy and paste the contents of hosts/laptop/default.nix to hosts/[yourhostname]/default.nix. You can then edit the value found in the hostname ? "evil", line, to be whatever default hostname you prefer. Then you can get into editing the settings.

theme

Defaults to rosepine with the gtk-nix flake's gtk theme. Available themes include "drifter", "orchis", "nordicWithGtkNix", "nordic", "gtk4", "rosepine", "gruvbox", "gruvboxWithGtkNix", and "amber-forest".

system

Defaults to "x86_64-linux". This is the only tested system.

username

Defaults to "argus". Change it to whatever you want your primary user's username to be.

useDvorak

Boolean which, when set to true, adds the Dvorak programmer layout to X based environments, and makes it the default while in a TTY.

allowedUnfree

A list of strings with the names of unfree packages you would like to allow. It always is merged with the contents of allowedUnfree from lib/settings-defaults.nix.

allowBroken

Defaults to false. Whether to allow broken packages. Useful when building with musl.

extraExtraSpecialArgs

Unused. Additional values to be passed into all home-manager modules.

extraSpecialArgs

Unused. Additional values to be passed into all nixos modules.

additionalModules

List of paths to nix module files. These will be imported in addition to user/primary/default.nix.

packageSelections

A set which must contain at least the following:

{
  unstable = _: _: {};
  remotebuild = _: _: {};
  localbuild = _: _: {};
}

Each of these is a function which will apply overlays. For example, if you want the steam package to be the version from the unstable branch, you could do the following:

{
  unstable = unstable: _:
    {
      steam = unstable.steam;
    };
  remotebuild = _: _: {};
  localbuild = _: _: {};
}

The second argument of the function is the original packageset.

additionalOverlays

A list of overlays to add to pkgs. Applied before packageSelections.

additionalNixosModules

Identical to additionalModules except these will be added to the nixpkgs.lib.nixosSystem call.

optimization

A complex set which must at least contain the following:

{
  optimization = {
    arch = "";
    useMusl = false;
    useFlags = false;
    useClang = false;
    useNative = false;
    USE = [];
  };
}

Setting useFlags to true will enable all of the custom build settings, and cause pretty much all your packages to build from source. Add compiler flags such as "-O3" to the USE list.

name

This value must always be set to "pkgs".

nix

Thise is merely a passthrough to config.nix. Available values include things like package, gc, distributedBuilds, settings, etc.

unstableOverrides, remotebuildOverrides, and localbuildOverrides

These are overrides which will be applied to the settings, but only for a single package set. Here are what they must contain at the bare minimum, respectively:

{
  unstableOverrides = {
    name = "unstable";
  };
  remotebuildOverrides = {
    name = "remotebuild";
  };
  localbuildOverrides = {
    name = "localbuild";
  };
}

These can be used to select certain packages to have specific optimizations, or to be cross-compiled on a remote machine. For example:

{
  packageSelections = {
    # make firefox be selected from the "remotebuild" packageset
    remotebuild = remotebuild: _:
      with remotebuild; {
        inherit firefox;
      };
    localbuild = _: _: {};
    unstable = _: _: {};
  };

  # configure the remotebuild packageset to use fancy optimizations
  remotebuildOverrides = {
    optimization = {
      useMusl = true;
      useFlags = true;
      useClang = true;
    };
    name = "remotebuild";
  };
}