nix-darwin

Nix modules for darwin, /etc/nixos/configuration.nix for macOS.

This project aims to bring the convenience of a declarative system approach to macOS. nix-darwin is built up around Nixpkgs, quite similar to NixOS.

Installing

To install nix-darwin, a working installation of Nix is required.

If you wish to use nix-darwin with flakes, please refer to the flakes section.

nix-build https://github.com/LnL7/nix-darwin/archive/master.tar.gz -A installer
./result/bin/darwin-installer

NOTE: the system activation scripts don't overwrite existing etc files, so files like /etc/bashrc and /etc/zshrc won't be updated by default. If you didn't use the installer or skipped some of the options you'll have to take care of this yourself. Either modify the existing file to source/import the one from /etc/static or remove it. Some examples:

• mv /etc/bashrc /etc/bashrc.before-nix-darwin
• echo 'if test -e /etc/static/bashrc; then . /etc/static/bashrc; fi' | sudo tee -a /etc/bashrc

Updating

The installer will configure a channel for this repository.

nix-channel --update darwin
darwin-rebuild changelog

NOTE: If you are using Nix as a daemon service the channel for that will be owned by root. Use sudo -i nix-channel --update darwin instead.

Uninstalling

There's also an uninstaller if you don't like the project and want to remove the configured files and services.

nix-build https://github.com/LnL7/nix-darwin/archive/master.tar.gz -A uninstaller
./result/bin/darwin-uninstaller

Example configuration

Configuration lives in ~/.nixpkgs/darwin-configuration.nix. Check out modules/examples for some example configurations.

{ pkgs, ... }:
{
  # List packages installed in system profile. To search by name, run:
  # $ nix-env -qaP | grep wget
  environment.systemPackages =
    [ pkgs.vim
    ];

  # Auto upgrade nix package and the daemon service.
  services.nix-daemon.enable = true;
  nix.package = pkgs.nix;
}

Flakes

nix-darwin aims for both non-flake and flake configurations to be well supported despite flakes being an experimental feature in Nix.

Step 1. Creating flake.nix

Getting started from scratch

If you don't have an existing configuration.nix, you can run the following commands to generate a basic flake.nix inside ~/.config/nix-darwin:

mkdir -p ~/.config/nix-darwin
cd ~/.config/nix-darwin
nix flake init -t nix-darwin
sed -i '' "s/simple/$(scutil --get LocalHostName)/" flake.nix

Make sure to change nixpkgs.hostPlatform to aarch64-darwin if you are using Apple Silicon.

Migrating from an existing configuration.nix

Add the following to flake.nix in the same folder as configuration.nix:

{
  description = "John's darwin system";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-23.05-darwin";
    nix-darwin.url = "github:LnL7/nix-darwin";
    nix-darwin.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = inputs@{ self, nix-darwin, nixpkgs }: {
    darwinConfigurations."Johns-MacBook" = nix-darwin.lib.darwinSystem {
      modules = [ ./configuration.nix ];
    };
  };
}

Make sure to replace Johns-MacBook with your hostname which you can find by running scutil --get LocalHostName.

Make sure to set nixpkgs.hostPlatform in your configuration.nix to either x86_64-darwin (Intel) or aarch64-darwin (Apple Silicon).

Step 2. Installing nix-darwin

Instead of using darwin-installer, you can just run darwin-rebuild switch to install nix-darwin. As darwin-rebuild won't be installed in your PATH yet, you can use the following command:

nix run nix-darwin -- switch --flake ~/.config/nix-darwin

Step 3. Using nix-darwin

After installing, you can run darwin-rebuild to apply changes to your system:

darwin-rebuild switch --flake ~/.config/nix-darwin

Using flake inputs

Inputs from the flake can also be passed into darwinSystem. These inputs are then accessible as an argument inputs, similar to pkgs and lib, inside the configuration.

# in flake.nix
nix-darwin.lib.darwinSystem {
  modules = [ ./configuration.nix ];
  specialArgs = { inherit inputs; };
}

# in configuration.nix
{ pkgs, lib, inputs }:
# inputs.self, inputs.nix-darwin, and inputs.nixpkgs can be accessed here

Manual Install

# Configure the channel
nix-channel --add https://github.com/LnL7/nix-darwin/archive/master.tar.gz darwin
nix-channel --update
export NIX_PATH=darwin-config=$HOME/.nixpkgs/darwin-configuration.nix:$HOME/.nix-defexpr/channels:$NIX_PATH

# Or use a local git repository
git clone git@github.com:LnL7/nix-darwin.git ~/.nix-defexpr/darwin
export NIX_PATH=darwin=$HOME/.nix-defexpr/darwin:darwin-config=$HOME/.nixpkgs/darwin-configuration.nix:$NIX_PATH

cp ~/.nix-defexpr/darwin/modules/examples/simple.nix ~/.nixpkgs/darwin-configuration.nix

# you can also use this to rebootstrap nix-darwin in case
# darwin-rebuild is to old to activate the system.
$(nix-build '<darwin>' -A system --no-out-link)/sw/bin/darwin-rebuild build
$(nix-build '<darwin>' -A system --no-out-link)/sw/bin/darwin-rebuild switch

. /etc/static/bashrc

... or for fish:

(nix-build '<darwin>' -A system --no-out-link)/sw/bin/darwin-rebuild build
(nix-build '<darwin>' -A system --no-out-link)/sw/bin/darwin-rebuild switch

This will create and manage a system profile in /run/current-system, just like NixOS.

By default, nix-darwin will look in your NIX_PATH for this repository at ~/.nix-defexpr/darwin and your configuration at ~/.nixpkgs/darwin-configuration.nix. If you want to change these you can set your own with nix.nixPath = [ ];.

$ darwin-rebuild switch
building the system configuration...
these derivations will be built:
  /nix/store/vfad6xgjzr56jcs051cg6vzch4dby92y-etc-zprofile.drv
  /nix/store/cbmkscxsz0k02ynaph5xaxm1aql0p3vq-etc.drv
  /nix/store/r5fpn177jhc16f8iyzk12gcw4pivzpbw-nixdarwin-system-16.09.drv
building path(s) ‘/nix/store/wlq89shja597ip7mrmjv7yzk2lwyh8n0-etc-zprofile’
building path(s) ‘/nix/store/m8kcm1pa5j570h3indp71a439wsh9lzq-etc’
building path(s) ‘/nix/store/l735ffcdvcvy60i8pqf6v00vx7lnm6mz-nixdarwin-system-16.09’
setting up /etc...
setting up launchd services...
writing defaults...
$

Documentation

Reference documentation of all the options is available here. This can also be accessed locally using man 5 configuration.nix.

darwin-help will open a HTML version of the manpage in the default browser.

Furthermore there's darwin-option to introspect the settings of a system and its available options.

NOTE: darwin-option is only available to non-flake installations.

$ darwin-option services.activate-system.enable
Value:
true

Default:
false

Example:
no example

Description:
Whether to activate system at boot time.

There's also a small wiki https://github.com/LnL7/nix-darwin/wiki about specific topics, like macOS upgrades.

Tests

There are basic tests that run sanity checks for some of the modules, you can run them like this:

# run all tests
nix-build release.nix -A tests
# or just a subset
nix-build release.nix -A tests.environment-path

Contributing

Let's make Nix on macOS awesome!

Don't hesitate to contribute modules or open an issue.

To build your configuration with local changes you can run this. This flag can also be used to override darwin-config or nixpkgs, for more information on the -I flag look at the nix-build manpage.

darwin-rebuild switch -I darwin=.

If you're adding a module, please add yourself to meta.maintainers, for example

  meta.maintainers = [
    lib.maintainers.alice or "alice"
  ];

  options.services.alicebot = # ...

The or operator takes care of graceful degradation when lib from Nixpkgs goes out of sync.

Also feel free to contact me if you have questions,

• Matrix - @daiderd:matrix.org, you can find me in #macos:nixos.org
• @LnL7 on twitter