# Nix Starter Config

This is a simple nix flake for getting started with NixOS + home-manager.

## What this provides

- NixOS configuration on `nixos/configuration.nix`, accessible via
  `nixos-rebuild --flake`
- Home-manager configuration on `home-manager/home.nix`, accessible via
  `home-manager --flake`
- Basic boilerplate for adding custom packages (under `pkgs`) and overlays
  (under `overlays`). Acessible on your system, home config, as well as `nix
  build .#package-name`
- Boilerplate for custom NixOS (`modules/nixos`) and home-manager
  (`modules/home-manager`) modules

## Getting started

Assuming you have a basic NixOS booted up (either live or installed, anything
works). Here's [a link to the latest NixOS downloads, just for
you](https://nixos.org/download#download-nixos)

### The repo

- [Install git](https://nixos.wiki/wiki/git)
- Clone this repo to somewhere acessible (somewhere in your home directory is
  good enough)

- Add stuff you currently have on `/etc/nixos/` to `nixos` (usually
  `configuration.nix` and `hardware-configuration.nix`, when you're starting
  out).
    - The included file has some options you might want, specially if you don't
      have a configuration ready. Make sure you have generated your own
      `hardware-configuration.nix`; if not, just mount your partitions to
      `/mnt` and run: `nixos-generate-config --root /mnt`.
- If you're already using home-manager, add your stuff from `~/.config/nixpkgs`
  to `home-manager` (probably `home.nix`).
  - I also include one with some simple options if you need. Feel free to
    ignore this step if you don't want to use home-manager just yet.
- Take a look at `flake.nix`, making sure to fill out anything marked with
  FIXME (required) or TODO (usually tips or optional stuff you might want)
- Create a remote repo (github, gitlab, sr.ht, etc) and push your changes for
  safekeeping (or at least copy your directory to somewhere safe, specially if you're on a installation medium)

### Bootstrapping
To get everything up and running, you need flake-enabled nix and home-manager.

First off, check your nix version using `nix --version`.

#### Version < 2.4
Bummer, your nix version does not support flakes. But fear not!

You _don't_ need to mess around with channels to get up and running.

Just run:
```bash
nix-shell
```

Wow, that was easy. Our `shell.nix` file will detect you can't evaluate (nor
lock) the flake, and will grab `nix` and `home-manager` from the latest
`nixos-unstable` versions, just for you.

Once you're bootstrapped, remember to run `nix flake lock` and commit the
newly-created `flake.lock` into your repository, this will make future
bootstraps reproductible.

#### Version >= 2.4
Congrats, your nix version supports flakes! It's just hidden behind a feature flag.

You can bootstrap with: 
```bash
nix develop .#default
```

This should generate a `flake.lock`. Remember to commit it, as this will make
future bootstraps reproductible.

### Usage

- Run `sudo nixos-rebuild switch --flake .#hostname` to apply your system
  configuration.
    - If you're still on a live installation medium, run `nixos-install --flake
      .#hostname` instead, and reboot. Ignore the home-manager step for now.
- Run `home-manager switch --flake .#username@hostname` to apply your home
  configuration.

And that's it, really! You're ready to have fun with your configurations using
the latest and greatest nix3 flake-enabled command UX.

## What next?

### User password and secrets

For people fresh from installation: Unless you used `--no-root-passwd`,
`nixos-install` prompted you for a root password. Use it to log into the root
account, set your own account's password imperatively with `passwd`, and
disable root login (`sudo passwd -l root`). You can also use `--no-root-passwd`
and instead set `initialPassword` for your user, for a temporary password upon
install.

If you don't want to set your password imperatively, you can also use
`passwordFile` for safely and declaratively setting a password from a file
outside the nix store.

There's also more advanced options for secret management, including some that
can include them (encrypted) into your config repo and/or nix store, be sure to
check them out if you're interested.

### Include files using home-manager

Besides just adding packages to your environment, home-manager can also manage
your dotfiles. I strongly recommend you do, it's awesome!

For full nix goodness, check out the home-manager modules with `man
home-configuration.nix`. Using them, you'll be able to fully configure any
usual dotfile with nix syntax and abstractions (including your own powerful
modules and functions).

Alternatively, if you're still not ready to rewrite all your configs in nix
syntax, there's home-manager options (such as `xdg.configFile`) for including
files from your nix-config repository into your config directories. Add your
existing dotfiles to this repo and try it out!

### Try opt-in persistance

You might have noticed that there's impurity in your NixOS system, in the form
of configuration files and other cruft your system generates when running. What
if you change them in a whim? Boom, your system is not fully reproductible
anymore.

You can instead fully delete your `/` and `/home` on every boot! Nix is okay
with a empty root on boot, and will happily reapply your configurations (as
long as `/nix` is intact).

There's two main approaches to this: mount a `tmpfs` (RAM disk) to `/`, or
(using a filesystem such as btrfs or zfs) mount a blank snapshot and reset it
on boot.

For stuff that can't be managed through nix (such as games downloaded from
steam, or logs), use [impermanence](https://github.com/nix-community/impermanence)
for mounting stuff you to keep to a separate partition/volume (such as
`/nix/persist` or `/persist`). This makes everything vanish by default, and you
can keep track of what you specifically asked to be kept.


### Customize your NixOS configuration

Use the `nixos/configuration.nix` file.

For a list of options, see `man configuration.nix`. Also see [the
manual](https://nixos.org/manual/nixos/stable/index.html#ch-configuration).

### Customize your home-manager configuration

Use the `home-manager/home.nix` file.

For a list of options, see `man home-configuration.nix`. Also see [the
manual](https://rycee.gitlab.io/home-manager/index.html#ch-usage).


### Adding packages

Create a folder with the package name inside `pkgs`, and add a `default.nix`
file containing a derivation. Be sure to also `callPackage` them on
`pkgs/default.nix`.

See [the manual](https://nixos.org/manual/nixpkgs/stable/).

### Adding overlays

Use the `overlay/default.nix` file.

If you're applying patches, you can keep them on the `overlay` folder as well.

See [the wiki article](https://nixos.wiki/wiki/Overlays).

### Adding your own modules

Create a file for them on either `modules/nixos` or `modules/home-manager`. Be
sure to also add them to the listing at `modules/nixos/default.nix` or
`modules/home-manager/default.nix`.

See [the wiki article](https://nixos.wiki/wiki/Module).

### Adding more hosts or users
You can organize them by hostname and username on `nixos` and `home-manager`
directories, be sure to also add them to `flake.nix`