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.

Install

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

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.orig
• echo 'if test -e /etc/static/bashrc; then . /etc/static/bashrc; fi' | sudo tee -a /etc/bashrc
• echo 'if test -e /etc/static/bashrc; then . /etc/static/bashrc; fi' | tee -a ~/.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 (experimental)

There is also preliminary support for building your configuration using a flake. This is mostly based on the flake support that was added to NixOS.

A minimal example of using an existing configuration.nix:

{
  description = "John's darwin system";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-23.05-darwin";
    darwin.url = "github:lnl7/nix-darwin/master";
    darwin.inputs.nixpkgs.follows = "nixpkgs";
  };

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

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

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

Since the installer doesn't work with flakes out of the box yet, nix-darwin will need to be bootstrapped using the installer or manually. Afterwards the flake based configuration can be built. The hostname(1) of your system will be used to decide which darwin configuration is applied if it's not specified explicitly in the flake ref.

nix build ~/.config/darwin\#darwinConfigurations.Johns-MacBook.system
./result/sw/bin/darwin-rebuild switch --flake ~/.config/darwin

Manual Install

# Before 10.15 Catalina
sudo ln -s private/var/run /run
# After 10.15 Catalina
echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf
/System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B
/System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t

# 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.

The default NIX_PATH in nix-darwin will look for this repository in ~/.nix-defexpr/darwin and for your configuration in ~/.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 darwin 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