nix-darwin/README.md

[<img src="https://daiderd.com/nix-darwin/images/nix-darwin.png" width="200px" alt="logo" />](https://github.com/LnL7/nix-darwin)

# nix-darwin

![Test](https://github.com/LnL7/nix-darwin/workflows/Test/badge.svg)

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](https://github.com/NixOS/nixpkgs), quite similar to [NixOS](https://nixos.org/).

## Installing

To install nix-darwin, a working installation of [Nix](https://github.com/NixOS/nix#installation) is required.

If you wish to use nix-darwin with flakes, please refer to the [flakes](#flakes) section.

```bash
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.

```bash
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.

```bash
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](https://github.com/LnL7/nix-darwin/tree/master/modules/examples) for some example configurations.

```nix
{ 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`

<details>
<summary>Getting started from scratch</summary>
<p></p>

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`:

```bash
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.

</details>

<details>
<summary>Migrating from an existing configuration.nix</summary>
<p></p>

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

```nix
{
  description = "John's darwin system";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-23.11-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).

</details>

### 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:

```bash
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:

```bash
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.

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

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

## Manual Install

```bash
# 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 too 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`:

```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](https://daiderd.com/nix-darwin/manual/index.html).
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:

```bash
# 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](https://nixos.org/manual/nix/stable/command-ref/nix-build.html).

```bash
darwin-rebuild switch -I darwin=.
```

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

```nix
  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](https://matrix.to/#/#macos:nixos.org)
- @LnL7 on twitter