refactor: Make hw definitions modules with mkIf guards

fleet/boot.nix

@@ -5,9 +5,24 @@
 # - Bootloader configuration (systemd-boot with Plymouth)
 # - Timezone and locale settings
 # - Systemd sleep configuration
+#
+# Only applies to:
+# - Linux systems (not Darwin/macOS)
+# - Systems with actual boot hardware (not containers/WSL)
 
-{ lib, ... }:
 {
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  # Check if this is a bootable system (not container, not WSL)
+  isBootable = !(config.boot.isContainer or false) && (pkgs.stdenv.isLinux);
+in
+{
+  config = lib.mkIf isBootable {
     boot = {
       loader.systemd-boot.enable = lib.mkDefault true;
       loader.efi.canTouchEfiVariables = lib.mkDefault true;
@@ -45,4 +60,5 @@
       SuspendState=freeze
       HibernateDelaySec=2h
     '';
+  };
 }

fleet/common.nix

@@ -7,8 +7,14 @@
 {
   config,
   lib,
+  inputs,
   ...
 }:
+let
+  # Import all hardware modules so they're available for enabling
+  hwTypes = import ../hw { inherit inputs; };
+  hwModules = lib.attrValues hwTypes;
+in
 {
   imports = [
     ./fs.nix
@@ -16,7 +22,9 @@
     ./user-config.nix
     ./fleet-option.nix
     ../sw
-  ];
+    inputs.vscode-server.nixosModules.default
+    inputs.nixos-wsl.nixosModules.default
+  ] ++ hwModules;
 
   options.athenix = {
     forUser = lib.mkOption {

fleet/default.nix

@@ -20,8 +20,6 @@ let
   # Import fleet-option.nix (defines athenix.fleet) and inventory.nix (sets values)
   # We use a minimal module here to avoid circular dependencies from common.nix's imports
 
-  hostTypes = config.athenix.hwTypes;
-
   # Helper to create a single NixOS system configuration
   mkHost =
     {
@@ -123,11 +121,6 @@ let
         }
       ) userNixosModulePaths;
 
-      # Get the host type module from the hostTypes attribute set
-      typeModule =
-        hostTypes.${hostType}
-          or (throw "Host type '${hostType}' not found. Available types: ${lib.concatStringsSep ", " (lib.attrNames hostTypes)}");
-
       # External module from fetchGit/fetchurl
       externalPathModule =
         if externalModulePath != null then import externalModulePath { inherit inputs; } else { };
@@ -155,18 +148,24 @@ let
           ];
         };
 
+      # Hardware-specific external modules
+      hwSpecificModules =
+        lib.optional (hostType == "nix-lxc") "${inputs.nixpkgs.legacyPackages.${system}.path}/nixos/modules/virtualisation/proxmox-lxc.nix";
+
       allModules =
         userNixosModules
         ++ [
           ./common.nix
-          typeModule
           overrideModule
           { networking.hostName = hostName; }
           {
             # Inject user definitions from flake-parts level
             config.athenix.users = lib.mapAttrs (_: user: lib.mapAttrs (_: lib.mkDefault) user) users;
           }
+          # Enable the appropriate hardware module based on hostType
+          { config.athenix.hw.${hostType}.enable = lib.mkDefault true; }
         ]
+        ++ hwSpecificModules
         ++ lib.optional (externalModulePath != null) externalPathModule;
     in
     {

fleet/fs.nix

@@ -4,9 +4,17 @@
 # This module defines:
 # - Disko partition layout (EFI, swap, root)
 # - Filesystem options (device, swap size)
+#
+# Only applies to systems with physical disk management needs
+# (not containers, not WSL, not systems without a configured device)
 
 { config, lib, ... }:
 
+let
+  cfg = config.athenix.host.filesystem;
+  # Only enable disk config if device is set and disko is enabled
+  hasDiskConfig = cfg.device != null && config.disko.enableConfig;
+in
 {
   options.athenix = {
     host.filesystem = {
@@ -49,14 +57,17 @@
     };
   };
 
-  config = {
+  config = lib.mkMerge [
+    {
       # ========== Disk Partitioning (Disko) ==========
-    disko.enableConfig = lib.mkDefault (config.athenix.host.filesystem.device != null);
+      disko.enableConfig = lib.mkDefault (cfg.device != null);
+    }
 
+    (lib.mkIf hasDiskConfig {
       disko.devices = {
         disk.main = {
           type = "disk";
-        device = config.athenix.host.filesystem.device;
+          device = cfg.device;
           content = {
             type = "gpt";
             partitions = {
@@ -79,10 +90,10 @@
               };
 
               # Swap Partition (size configurable per host)
-            swap = lib.mkIf config.athenix.host.filesystem.useSwap {
+              swap = lib.mkIf cfg.useSwap {
                 name = "swap";
                 label = "swap";
-              size = config.athenix.host.filesystem.swapSize;
+                size = cfg.swapSize;
                 content = {
                   type = "swap";
                 };
@@ -107,5 +118,6 @@
           };
         };
       };
-  };
+    })
+  ];
 }

hw/nix-desktop.nix

@@ -10,11 +10,33 @@
   modulesPath,
   ...
 }:
+
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-desktop;
+in
 {
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
   ];
 
+  options.athenix.hw.nix-desktop = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable desktop workstation hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "Desktop workstation hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
+
     # ========== Boot Configuration ==========
 
     boot.initrd.availableKernelModules = [
@@ -47,4 +69,5 @@
     # ========== Software Profile ==========
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.desktop.enable = lib.mkDefault true;
+  };
 }

hw/nix-ephemeral.nix

@@ -11,11 +11,32 @@
   modulesPath,
   ...
 }:
+
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-ephemeral;
+in
 {
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
   ];
 
+  options.athenix.hw.nix-ephemeral = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable ephemeral/diskless system hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "Ephemeral hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
     # ========== Boot Configuration ==========
     boot.initrd.availableKernelModules = [
       "xhci_pci" # USB 3.0 support
@@ -63,4 +84,5 @@
 
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.stateless-kiosk.enable = lib.mkDefault true;
+  };
 }

hw/nix-laptop.nix

@@ -10,11 +10,32 @@
   modulesPath,
   ...
 }:
+
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-laptop;
+in
 {
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
   ];
 
+  options.athenix.hw.nix-laptop = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable laptop hardware configuration with power management.";
+        };
+      };
+    };
+    default = { };
+    description = "Laptop hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
     # ========== Boot Configuration ==========
 
     boot.initrd.availableKernelModules = [
@@ -60,4 +81,5 @@
 
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.desktop.enable = lib.mkDefault true;
+  };
 }

hw/nix-lxc.nix

@@ -5,17 +5,32 @@
 # Disables boot/disk management and enables remote development support.
 
 {
+  config,
   lib,
-  modulesPath,
-  inputs,
   ...
 }:
-{
-  imports = [
-    inputs.vscode-server.nixosModules.default
-    "${modulesPath}/virtualisation/proxmox-lxc.nix"
-  ];
 
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-lxc;
+in
+{
+  options.athenix.hw.nix-lxc = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Proxmox LXC container hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "Proxmox LXC hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
     # ========== Nix Configuration ==========
     nix.settings.trusted-users = [
       "root"
@@ -57,4 +72,5 @@
 
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.headless.enable = lib.mkDefault true;
+  };
 }

hw/nix-surface.nix

@@ -12,7 +12,11 @@
   inputs,
   ...
 }:
+
+with lib;
+
 let
+  cfg = config.athenix.hw.nix-surface;
   # Use older kernel version for better Surface Go compatibility
   refSystem = inputs.nixpkgs-old-kernel.lib.nixosSystem {
     system = pkgs.stdenv.hostPlatform.system;
@@ -26,6 +30,21 @@ in
     inputs.nixos-hardware.nixosModules.microsoft-surface-go
   ];
 
+  options.athenix.hw.nix-surface = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Microsoft Surface tablet hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "Microsoft Surface hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
     # ========== Boot Configuration ==========
 
     boot.initrd.availableKernelModules = [
@@ -66,4 +85,5 @@ in
     # ========== Software Profile ==========
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.tablet-kiosk.enable = lib.mkDefault true; # Touch-optimized kiosk mode
+  };
 }

hw/nix-wsl.nix

@@ -7,16 +7,30 @@
 {
   lib,
   config,
-  inputs,
   ...
 }:
-{
-  imports = [
-    inputs.nixos-wsl.nixosModules.default
-    inputs.vscode-server.nixosModules.default
-  ];
 
-  # ========== Options ==========
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-wsl;
+in
+{
+  options.athenix.hw.nix-wsl = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Windows Subsystem for Linux hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "WSL hardware type configuration.";
+  };
+
+  # WSL user option (at module level, not inside config)
   options.athenix.host.wsl.user = lib.mkOption {
     type = lib.types.str;
     default = "engr-ugaif";
@@ -29,7 +43,7 @@
     example = "alice";
   };
 
-  config = {
+  config = mkIf cfg.enable {
     # ========== WSL Configuration ==========
     wsl.enable = true;
     # Use forUser if set, otherwise fall back to wsl.user option
@@ -55,5 +69,8 @@
     # Provide dummy values for required options from boot.nix
     athenix.host.filesystem.device = "/dev/null";
     athenix.host.filesystem.swapSize = "0G";
+
+    # WSL doesn't use installer ISOs
+    athenix.host.buildMethods = lib.mkDefault [ ];
   };
 }

hw/nix-zima.nix

@@ -10,11 +10,32 @@
   modulesPath,
   ...
 }:
+
+with lib;
+
+let
+  cfg = config.athenix.hw.nix-zima;
+in
 {
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
   ];
 
+  options.athenix.hw.nix-zima = mkOption {
+    type = types.submodule {
+      options = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Zima-specific hardware configuration.";
+        };
+      };
+    };
+    default = { };
+    description = "Zima hardware type configuration.";
+  };
+
+  config = mkIf cfg.enable {
     # ========== Boot Configuration ==========
 
     boot.initrd.availableKernelModules = [
@@ -46,4 +67,5 @@
     # ========== Software Profile ==========
     athenix.sw.enable = lib.mkDefault true;
     athenix.sw.desktop.enable = lib.mkDefault true;
+  };
 }

sw/ghostty.nix

@@ -1,4 +1,6 @@
 {
+  config,
+  lib,
   pkgs,
   ...
 }:
@@ -10,7 +12,11 @@
 # It reconstructs the terminfo database from the provided definition and
 # adds it to the system packages.
 
+with lib;
+
 let
+  cfg = config.athenix.sw;
+
   ghostty-terminfo = pkgs.runCommand "ghostty-terminfo" { } ''
     mkdir -p $out/share/terminfo
     cat > ghostty.info <<'EOF'
@@ -99,5 +105,7 @@ let
   '';
 in
 {
+  config = mkIf cfg.enable {
     environment.systemPackages = [ ghostty-terminfo ];
+  };
 }

sw/python.nix

@@ -18,11 +18,28 @@ let
   cfg = config.athenix.sw.python;
 in
 {
-  options.athenix.sw.python = {
-    enable = mkEnableOption "Python development tools (pixi, uv)" // {
+  options.athenix.sw.python = lib.mkOption {
+    type = lib.types.submodule {
+      options = {
+        enable = lib.mkOption {
+          type = lib.types.bool;
           default = true;
+          description = ''
+            Enable Python development tools (pixi, uv).
+
+            Provides:
+            - pixi: Fast, cross-platform package manager for Python
+            - uv: Extremely fast Python package installer and resolver
+
+            These tools manage project-based dependencies rather than global
+            Python packages, avoiding conflicts and improving reproducibility.
+          '';
         };
       };
+    };
+    default = { };
+    description = "Python development environment configuration.";
+  };
 
   config = mkIf cfg.enable {
     environment.systemPackages = [

sw/update-ref.nix

@@ -1,5 +1,17 @@
-{ pkgs, ... }:
 {
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+with lib;
+
+let
+  cfg = config.athenix.sw;
+in
+{
+  config = mkIf cfg.enable {
     environment.systemPackages = with pkgs; [
     python3
     git
@@ -508,4 +520,5 @@
       printf "  rev = %s\n" "$CUR_REV" >&2
     '')
   ];
+  };
 }