I published my Nix configuration

I finally got around to publishing my Nix configuration publicly on GitHub. I avoided doing this for a while since I had some details from my work Nix configuration that I didn’t want to publish, so I pulled those out and made a new repo, which you can find here.

In this post I detail some of the points that I am pleased with from my configuration and that might prove interesting to other Nix enthusaists. I cannot claim to be particularly skilled with Nix, merely that my setup works well for me. Reach out if you see room for improvement.

File Structure

My project structure is fairly simple, which has been a goal for me. I much prefer a few, larger files, to many small files. I find the benefit to spreading things out to be very minimal, and causes more clutter than it’s worth.

To that end, my directory structure is something like this:

├── flake.nix                 # Main flake configuration
├── systems/
│   ├── mac-configuration.nix          # macOS system configuration
│   ├── xps-configuration.nix          # NixOS system configuration
│   └── xps-hardware-configuration.nix # Dell XPS hardware config
├── home/
│   ├── personal-mac.nix      # personal Macbook Home Manager config
│   ├── personal-nixos.nix    # persoanl NixOS Home Manager config
│   ├── ubuntu-vm.nix         # Ubuntu VM Home Manager config
│   ├── common.nix            # Shared Home Manager configuration
│   └── modules/
│       ├── browser.nix       # firefox
│       ├── taskwarrior.nix   # taskwarrior
│       └── vscode.nix        # VS Code configuration

At the top level is the flake.nix. Then, we have two folders, systems and home. Systems contains a configuration for each of my hardware systems. For example, my Macbook, my Dell XPS running NixOS, or even a NixOS VM. This means each system will have one file, in the case of nix-darwin, or two for NixOS, as we need a hardware.nix.

Home Manager

Inside home at the top level is the common.nix. This file contains most of my configuration, such as zsh prompt and plugins, Git preferences, packages to install, shell aliases, tmux, and so on. It takes a few extra inputs: the name of an SSH key, an email, and a username. These are used to populate details like signing keys and Git.

Also in home are files specific to a single machine. For example, my Macbook, or my NixOS machine. These import common.nix, setting _module.args for the aforementioned inputs, and overriding configurations where necessary with lib.mkForce.

This leads to a maintainble structure that doesn’t have an excess of files to browse, and keeps most things shared, meaning I get the exact same experience no matter what machine I’m on.

Notes on nix-darwin

nix-darwin is a project that brings the declarative power of NixOS to MacOS. It works very well and I love using it. I wanted to note the trouble with installing packages, however (Note: this may have been patched, I am yet to try it). Installing GUI applications on Nix places them into the Nix store, aliased into a directory like /Users/<user>/Applications/Home Manager Apps. The issue here is that Spotlight search does not index these aliases, meaning you won’t find them easily on your system, and they’ll look like aliases.

My preferred method of installing GUI apps is to use nix-homebrew with casks. This is a good compromise and lets the apps update themselves too.

Managing Firefox

Using home-manager to configure Firefox is pretty easy. The difficulty is discovering what you can set. Use about:config in Firefox to search for preferences and see what might be worth setting.

Conclusion

My Nix config has required little tweaking. Or, rather, I have not been overly compelled to edit it. This must be a combination of having landed on a solid config, and some level of mental fortitude to be glad when something is working. Reach out if you have any ideas or comments.