nixin

User configs, server configs, PC configs, who knows?

This repo's got my Nix configuration files for most of everything I can switch over. It's a public repo because that leaves a non-0 chance that wandering eyes with more knowledge than me can help me organize this mess better.

Mental Model

I'm currently early on to developing my understanding of the various components of nix. For the sake of this repo, I have a working model I'll be explaining here.

Roles

In my head, a role is a logical grouping of configurations that accomplish a goal across various system types. For example, the users/danh role represents everything involved in configuring access for my user across hosts, including both OS configs as well as my personal preferences and dotfiles.

That is, a role isn't a nix module at all, but instead a logical grouping of modules. This primarily due to there being various kinds of configurations that are all necessary to accomplish broader goals on a system.

The different configuration types are accessed is by directly importing the module matching the type of the calling config. In other words, a nix-darwin darwinSystem would import the ./modules/users/darwin.nix module and a home-manager homeManagerConfiguration would import the ./modules/users/home.nix module.

Outputs

Because I intend to write configurations for more than just nixos hosts, I'm not following the common pattern of defining host configs with included user configs. The functional differences between even nix-darwwin and nixos configs alone is enough for me to not bother trying to have all my outputs represent "whole-host configurations". Instead, each output is a configuration specific to just the scope of the target tool. It is then up to the target environment to call the appropriate tools for each output configuration to produce the intended final host state.

So for the danh user on the the keylime host, the result would be calling nix-darwin switch as well as home-manager switch following a general nix installation.

Structure

flake.nix

Entry point for the whole thing, this is where all configurations can be built from.

Notably different (wrong? probably!) from expectations for flakes, is that to enable system-agnostic output selection for nix-darwin and home-manager configurations, I've opted to set packages.${system}.{home,darwin}Configurations for each supported system.

Really the benefit here is being able to switch to a specific home-manager configuration using the same flake output name regardless of whether I'm on NixOS or MacOS.

modules/

The sub-directories here are my classification for "role" types. This is purely semantics and has no functionality beyond organization. There's currently only two role types:

• users: represents a real person or service account that would have access to a host
• hosts: represents a machine that would have some component about it configured by some nix tool

Under each role, there will be module files for each configuration type needed to accomplish the role's intent. These will be directly imported up in flake.nix according to the output being defined.

modules/{roleType}/{roleName}/options.nix

For each role, I've included a place for common module options that could span across different configuration types. These options will at least include an enable option for the role, such that importing a role's module is not enough to evaluate the entire config.

So for the danh role, for example, the nixin.users.danh.enable option must be true to actually render the config of whatever role modules were imported.

Usage

if you're me

# for nix-darwin
nix run nix-darwin -- switch --flake .#danh@keylime # or .#danh@okra or w.e.

# for nixos
sudo nixos-rebuild switch --flake .#mandarin # or w.e.

# with nix installed on any system
nix run home-manager -- switch --flake .#danh@home # or @work or w.e.

# with devbox, direnv, and just installed
just b mandarin # or any target flake, tool selected automatically

if you're not

lol don't ❤️