nix-configurations

My personal NixOS configurations, using the Dendritic Pattern.

TL;DR

The dendritic pattern takes your flake and literally breaks it into parts. Each file is its own module, be it a nixosModules or homeModules module, or even an entire nixosConfiguration definition, typically via flake-parts and import-tree.

How do I do it?

The top-level flake.nix uses flake-part's helper function, then pass import-tree ./modules to it. Everything within the ./modules tree gets imported as a flake-parts module without the need for glue code (no default.nix that lists every file).

How are modules used?

Each module is defined through flake.{nixosModules,homeModules,etc}.moduleName, which can then be referenced through self.{nixosModules,homeModules,etc}.moduleName. These modules are then imported into each nixosConfigurations.hostName as such:

activeModules = with self.nixosModules; [
  core disko lanzaboote nvidia
  kde gaming develop stylix workstation
  lament # yes, even my user itself is a module
];
# then, within the host or user definition
modules = activeModules ++ [
  # other things, such as 
  {system.stateVersion = "26.05";}
];

Custom lib? In flake-parts?

flake.myLib is a custom flake-parts option using types.lazyAttrsOf types.raw so that each part of the lib can be written as an individual module and merge together just like nixosModules or homeModules.

Structure

modules/
  nixosConfigurations/
    athena.nix  ## Linode VPS, service host
    ishtar.nix  ## Personal desktop
  nixosModules/
    hardware/
    profiles/
    services/
    system/
  homeModules/
    apps/
    shell/
  diskoConfigurations/
    ${hostName}.nix
    module.nix  ## placement by colocation, diskoConfiguration handler
  users/        ## see notes below
  packages.nix  ## single entrypoint for packages
static/         ## host-specific, or not modularized yet
  {hostname}/
  packages/     ## see note below

Modules are organized by output type then by semantic category.

Notes

• I use home-manager at the system level.
• No, users is not a valid flake output, but it made sense to keep it as a separate concern.
• For packages, without serious Googling I couldn't figure out how to in-line the actual package declaration, so I use static/packages for that.
• "You only have the two hosts, so this level of organization is overkill." Yes, yes it is.
• "You only have the two hosts, so having device specific overrides is overkill." Yes. Yes it is.

So... Why?

Honestly? I liked the way the Dendritic Pattern looked on paper, and the idea of dropping a new module into the flake tree and importing it into my system instead of glue coding it (and args like self) in, just to forget where I put it, was enough. Need to change how ZSH works? homeModules. Caddy? nixosModules. New host? New file in nixosConfigurations. As long as I know what I want to change, where it is becomes obvious.

License

MIT