Home Manager using Nix
======================

This project provides a basic system for managing a user environment
using the [Nix][] package manager together with the Nix libraries
found in [Nixpkgs][]. Before attempting to use Home Manager please
read the warning below.

Words of warning
----------------

This project is in early development! I personally use it to manage
several user configurations but it may fail catastrophically for you.
So beware!

To configure programs and services the Home Manager must write various
things to your home directory and possibly overwrite files you have
previously created. For example, if you use Home Manager to install
and configure Git then your `~/.gitconfig` will be replaced by a link
to a configuration generated by Home Manager:

```
$ ls -gG ~/.gitconfig
lrwxrwxrwx 1 73 Jan  8 21:59 /home/rycee/.gitconfig -> /nix/store/pk7g12816avnxyhnkbdhqhnlzrw7fsga-home-manager-files/.gitconfig
```

So, if you already have a wonderful, painstakingly created
`~/.gitconfig` it will be gone. Home Manager will _not_ attempt to
backup the previous `~/.gitconfig` file.

Further, Home Manager targets [NixOS][] version 17.03 (the current
stable version), it may or may not work on other Linux distributions
and NixOS versions.

Finally, the `home-manager` tool does not explicitly support rollbacks
at the moment so if your home directory gets messed up you'll have to
fix it yourself (you can attempt to run the activation script for the
desired generation).

Now when your expectations have been built up and you are eager to try
all this out you can go ahead and read the rest of this text.

Installation
------------

Currently the easiest way to install Home Manager is as follows:

 1. Make sure you have a working Nix installation.

 2. Clone the Home Manager repository into the `~/.nixpkgs` directory:

    ```
    $ git clone https://github.com/rycee/home-manager ~/.nixpkgs/home-manager
    ```

 3. Add Home Manager to your user's Nixpkgs, for example by adding it
    to the `packageOverrides` section in your `~/.nixpkgs/config.nix`
    file:

    ```nix
    {
      packageOverrides = pkgs: rec {
        home-manager = import ./home-manager { inherit pkgs; };
      };
    }
    ```

 4. Install the `home-manager` package:

    ```
    $ nix-env -f '<nixpkgs>' -iA home-manager
    installing ‘home-manager’
    ```

Usage
-----

The `home-manager` package installs a tool that is conveniently called
`home-manager`. This tool can apply configurations to your home
directory, list user packages installed by the tool, and list the
configuration generations.

As an example, let us set up a very simple configuration that installs
the htop and fortune packages, installs Emacs with a few extra
packages enabled, installs Firefox with Adobe Flash enabled, and
enables the user gpg-agent service.

First create a file `~/.nixpkgs/home.nix` containing

```nix
{ pkgs, ... }:

{
  home.packages = [
    pkgs.htop
    pkgs.fortune
  ];

  programs.emacs = {
    enable = true;
    extraPackages = epkgs: [
      epkgs.nix-mode
      epkgs.magit
    ];
  };

  programs.firefox = {
    enable = true;
    enableAdobeFlash = true;
  };

  services.gpg-agent = {
    enable = true;
    defaultCacheTtl = 1800;
    enableSshSupport = true;
  };
}
```

To activate this configuration you can then run

```
$ home-manager switch
```

or if you are not feeling so lucky,

```
$ home-manager build
```

which will create a `result` link to a directory containing an
activation script and the generated home directory files.

[Nix]: https://nixos.org/nix/
[NixOS]: https://nixos.org/
[Nixpkgs]: https://nixos.org/nixpkgs/