documentation/docs/alpine-desktop-setup/post-install/user-packages.md

# User packages

The *Nix package manager* is a package manager which allows for user independent packages and a whole lot more, although it is not necessarily minimal. 

## Setup

To set `nix` up install its package and activate its service:

```
# apk add nix
# rc-update add nix-daemon default
# rc-service nix-daemon start
```

Do not forget to add your user to the nix group:

```
# adduser <username> nix
```

### Channels

For `nix` to be able to install packages it is necessary to add a few channels/repositories in `~/.nix-channels`:

```
https://nixos.org/channels/nixos-<version> nixpkgs
https://nixos.org/channels/nixos-unstable nixpkgs-unstable
https://github.com/nix-community/nixGL/archive/main.tar.gz nixgl
```

and replace the `version` with the latest version of `nix`. Then perform

```
$ nix-channel --update
```

## Home manager

Nix can be used to manage your `$HOME` with `home-manager`. First install `home-manager` through:

```
$ nix-env -iA nixpkgs.home-manager
```

Now that Nix is up and running utilize the `home.nix` that comes with the [config files](https://docs.bijl.us/alpine-desktop-setup/post-install/config-files/) to set up your home. But before initialising `nix` make sure that you set the correct `<username>` in `home.nix` which is located in `~/.config/home-manager`. Then after changing that simply run this command:

```
$ home-manager switch
```

Thanks to `home-manager` we can easily set up and manage an entire graphical environment with all the necessary packages in one go. 

You are now also able to install packages as a user without root from `nixpkgs`:

```
$ nix-env -iA nixpkgs.<package>
```

But for reproducibility it is better to use `home-manager` by declaring them in a `.nix` file and importing that within `home.nix`.

You can also test a package before installing it with `nix-shell -p <program>`. 

### NixGL

The `nixGL` channel is necessary to be able to run graphical programs and sessions which are installed through `nix`. It should have been installed with `home-manager`. 

Some applications might need Vulkan in which case the program has to be prefixed with:

```
$ nixVulkanIntel <program>
```