flake: home-manager: export NixOS homes

And here is what the last few commits were building up to.

This is neat, but won't be useful *very* often.

flake/default.nix

@@ -13,6 +13,7 @@ flake-parts.lib.mkFlake { inherit inputs; } {
     ./checks.nix
     ./dev-shells.nix
     ./home-manager.nix
+    ./hosts.nix
     ./lib.nix
     ./nixos.nix
     ./overlays.nix

flake/home-manager.nix

@@ -1,5 +1,7 @@
-{ self, inputs, lib, ... }:
+{ self, config, inputs, lib, ... }:
 let
+  inherit (config) hosts;
+
   defaultModules = [
     # Include generic settings
     "${self}/modules/home"
@@ -14,9 +16,11 @@ let
       # Enable home-manager
       programs.home-manager.enable = true;
     }
+    # Import common modules
+    "${self}/modules/common"
   ];
 
-  mkHome = name: system: inputs.home-manager.lib.homeManagerConfiguration {
+  mkHomeCommon = mainModules: system: inputs.home-manager.lib.homeManagerConfiguration {
     # Work-around for home-manager
     # * not letting me set `lib` as an extraSpecialArgs
     # * not respecting `nixpkgs.overlays` [1]
@@ -29,34 +33,51 @@ let
       ];
     };
 
-    modules = defaultModules ++ [
-      "${self}/hosts/homes/${name}"
-    ];
+    modules = defaultModules ++ mainModules;
 
     extraSpecialArgs = {
       # Inject inputs to use them in global registry
       inherit inputs;
+      # For consumption by common modules
+      type = "home";
     };
   };
 
-  homes = {
+  mkHome = name: mkHomeCommon [ "${self}/hosts/homes/${name}" ];
+
+  mkNixosHome = name: mkHomeCommon [
+    "${self}/hosts/nixos/${name}/home.nix"
+    "${self}/hosts/nixos/${name}/profiles.nix"
+  ];
+in
+{
+  hosts.homes = {
     "ambroisie@bazin" = "x86_64-linux";
     "ambroisie@mousqueton" = "x86_64-linux";
   };
-in
-{
+
   perSystem = { system, ... }: {
     # Work-around for https://github.com/nix-community/home-manager/issues/3075
     legacyPackages = {
       homeConfigurations =
         let
-          filteredHomes = lib.filterAttrs (_: v: v == system) homes;
+          filteredHomes = lib.filterAttrs (_: v: v == system) hosts.homes;
           allHomes = filteredHomes // {
             # Default configuration
             ambroisie = system;
           };
+          homeManagerHomes = lib.mapAttrs mkHome allHomes;
+
+          filteredNixosHosts = lib.filterAttrs (_: v: v == system) hosts.nixos;
+          nixosHomes' = lib.mapAttrs mkNixosHome filteredNixosHosts;
+          nixosHomeUsername = (host: self.nixosConfigurations.${host}.config.my.user.name);
+          nixosHomes = lib.mapAttrs' (host: lib.nameValuePair "${nixosHomeUsername host}@${host}") nixosHomes';
         in
-        lib.mapAttrs mkHome allHomes;
+        lib.foldl' lib.mergeAttrs { }
+          [
+            homeManagerHomes
+            nixosHomes
+          ];
     };
   };
 }

flake/hosts.nix

@@ -0,0 +1,21 @@
+# Define `hosts.{darwin,home,nixos}` options for consumption in other modules
+{ lib, ... }:
+let
+  mkHostsOption = description: lib.mkOption {
+    inherit description;
+    type = with lib.types; attrsOf str;
+    default = { };
+    example = { name = "x86_64-linux"; };
+  };
+in
+{
+  options = {
+    hosts = {
+      darwin = mkHostsOption "Darwin hosts";
+
+      homes = mkHostsOption "Home Manager hosts";
+
+      nixos = mkHostsOption "NixOS hosts";
+    };
+  };
+}

flake/nixos.nix

@@ -1,4 +1,4 @@
-{ self, inputs, lib, ... }:
+{ self, config, inputs, lib, ... }:
 let
   defaultModules = [
     {
@@ -12,6 +12,8 @@ let
     }
     # Include generic settings
     "${self}/modules/nixos"
+    # Import common modules
+    "${self}/modules/common"
   ];
 
   buildHost = name: system: lib.nixosSystem {
@@ -24,12 +26,18 @@ let
       inherit (self) lib;
       # Inject inputs to use them in global registry
       inherit inputs;
+      # For consumption by common modules
+      type = "nixos";
     };
   };
 in
 {
-  flake.nixosConfigurations = lib.mapAttrs buildHost {
-    aramis = "x86_64-linux";
-    porthos = "x86_64-linux";
+  config = {
+    hosts.nixos = {
+      aramis = "x86_64-linux";
+      porthos = "x86_64-linux";
+    };
+
+    flake.nixosConfigurations = lib.mapAttrs buildHost config.hosts.nixos;
   };
 }

hosts/nixos/porthos/default.nix

@@ -7,6 +7,7 @@
     ./hardware.nix
     ./home.nix
     ./networking.nix
+    ./profiles.nix
     ./secrets
     ./services.nix
     ./system.nix

hosts/nixos/porthos/profiles.nix

@@ -0,0 +1,4 @@
+{ ... }:
+{
+  # Nothing
+}

modules/common/default.nix

@@ -0,0 +1,35 @@
+# Modules that are common to various module systems
+# Usually with very small differences, if any, between them.
+{ lib, type ? null, ... }:
+let
+  allowedTypes = [
+    "darwin"
+    "home"
+    "nixos"
+  ];
+
+  allowedTypesString = lib.concatStringSep ", " (builtins.map lib.escapeNixString allowedTypes);
+in
+{
+  imports = [
+    ./profiles
+  ];
+
+  config = {
+    assertions = [
+      {
+        assertion = type != null;
+        message = ''
+          You must provide `type` as part of specialArgs to use the common modules.
+          It must be one of ${allowedTypesString}.
+        '';
+      }
+      {
+        assertion = type != null -> builtins.elem type allowedTypes;
+        message = ''
+          `type` specialArgs must be one of ${allowedTypesString}.
+        '';
+      }
+    ];
+  };
+}

modules/common/profiles/bluetooth/default.nix

@@ -0,0 +1,19 @@
+{ config, lib, type, ... }:
+let
+  cfg = config.my.profiles.bluetooth;
+in
+{
+  options.my.profiles.bluetooth = with lib; {
+    enable = mkEnableOption "bluetooth profile";
+  };
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    (lib.optionalAttrs (type == "home") {
+      my.home.bluetooth.enable = true;
+    })
+
+    (lib.optionalAttrs (type == "nixos") {
+      my.hardware.bluetooth.enable = true;
+    })
+  ]);
+}

modules/common/profiles/default.nix

@@ -0,0 +1,25 @@
+# Configuration that spans accross system and home, or are almagations of modules
+{ config, lib, type, ... }:
+{
+  imports = [
+    ./bluetooth
+    ./devices
+    ./gtk
+    ./laptop
+    ./wm
+    ./x
+  ];
+
+  config = lib.mkMerge [
+    # Transparently enable home-manager profiles as well
+    (lib.optionalAttrs (type == "nixos") {
+      home-manager.users.${config.my.user.name} = {
+        config = {
+          my = {
+            inherit (config.my) profiles;
+          };
+        };
+      };
+    })
+  ];
+}

modules/common/profiles/devices/default.nix

@@ -0,0 +1,22 @@
+{ config, lib, type, ... }:
+let
+  cfg = config.my.profiles.devices;
+in
+{
+  options.my.profiles.devices = with lib; {
+    enable = mkEnableOption "devices profile";
+  };
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    (lib.optionalAttrs (type == "nixos") {
+      my.hardware = {
+        ergodox.enable = true;
+
+        mx-ergo.enable = true;
+      };
+
+      # MTP devices auto-mount via file explorers
+      services.gvfs.enable = true;
+    })
+  ]);
+}

modules/common/profiles/gtk/default.nix

@@ -0,0 +1,21 @@
+{ config, lib, type, ... }:
+let
+  cfg = config.my.profiles.gtk;
+in
+{
+  options.my.profiles.gtk = with lib; {
+    enable = mkEnableOption "gtk profile";
+  };
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    (lib.optionalAttrs (type == "home") {
+      # GTK theme configuration
+      my.home.gtk.enable = true;
+    })
+
+    (lib.optionalAttrs (type == "nixos") {
+      # Allow setting GTK configuration using home-manager
+      programs.dconf.enable = true;
+    })
+  ]);
+}

modules/common/profiles/laptop/default.nix

@@ -0,0 +1,27 @@
+{ config, lib, type, ... }:
+let
+  cfg = config.my.profiles.laptop;
+in
+{
+  options.my.profiles.laptop = with lib; {
+    enable = mkEnableOption "laptop profile";
+  };
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    (lib.optionalAttrs (type == "home") {
+      # Enable battery notifications
+      my.home.power-alert.enable = true;
+    })
+
+    (lib.optionalAttrs (type == "nixos") {
+      # Enable touchpad support
+      services.xserver.libinput.enable = true;
+
+      # Enable TLP power management
+      my.services.tlp.enable = true;
+
+      # Enable upower power management
+      my.hardware.upower.enable = true;
+    })
+  ]);
+}

modules/common/profiles/wm/default.nix

@@ -0,0 +1,36 @@
+{ config, lib, type, ... }:
+let
+  cfg = config.my.profiles.wm;
+
+  applyWm = wm: configs: lib.mkIf (cfg.windowManager == wm) (lib.my.merge configs);
+in
+{
+  options.my.profiles.wm = with lib; {
+    windowManager = mkOption {
+      type = with types; nullOr (enum [ "i3" ]);
+      default = null;
+      example = "i3";
+      description = "Which window manager to use";
+    };
+  };
+
+  config = lib.mkMerge [
+    (applyWm "i3" [
+      (lib.optionalAttrs (type == "home") {
+        # i3 settings
+        my.home.wm.windowManager = "i3";
+        # Screenshot tool
+        my.home.flameshot.enable = true;
+        # Auto disk mounter
+        my.home.udiskie.enable = true;
+      })
+
+      (lib.optionalAttrs (type == "nixos") {
+        # Enable i3
+        services.xserver.windowManager.i3.enable = true;
+        # udiskie fails if it can't find this dbus service
+        services.udisks2.enable = true;
+      })
+    ])
+  ];
+}

modules/common/profiles/x/default.nix

@@ -0,0 +1,27 @@
+{ config, lib, pkgs, type, ... }:
+let
+  cfg = config.my.profiles.x;
+in
+{
+  options.my.profiles.x = with lib; {
+    enable = mkEnableOption "X profile";
+  };
+
+  config = lib.mkIf cfg.enable (lib.mkMerge [
+    (lib.optionalAttrs (type == "home") {
+      # X configuration
+      my.home.x.enable = true;
+    })
+
+    (lib.optionalAttrs (type == "nixos") {
+      # Enable the X11 windowing system.
+      services.xserver.enable = true;
+      # Nice wallpaper
+      services.xserver.displayManager.lightdm.background =
+        let
+          wallpapers = "${pkgs.plasma5Packages.plasma-workspace-wallpapers}/share/wallpapers";
+        in
+        "${wallpapers}/summer_1am/contents/images/2560x1600.jpg";
+    })
+  ]);
+}

modules/nixos/default.nix

@@ -5,7 +5,6 @@
   imports = [
     ./hardware
     ./home
-    ./profiles
     ./programs
     ./secrets
     ./services

modules/nixos/home/default.nix

@@ -13,16 +13,23 @@ in
 
   config = lib.mkIf cfg.enable {
     home-manager = {
-      # Not a fan of out-of-directory imports, but this is a good exception
-      users.${config.my.user.name} = import "${inputs.self}/modules/home";
+      users.${config.my.user.name} = {
+        # Not a fan of out-of-directory imports, but this is a good exception
+        imports = [
+          "${inputs.self}/modules/common"
+          "${inputs.self}/modules/home"
+        ];
+      };
 
       # Nix Flakes compatibility
       useGlobalPkgs = true;
       useUserPackages = true;
 
-      # Forward inputs to home-manager configuration
       extraSpecialArgs = {
+        # Forward inputs to home-manager configuration
         inherit inputs;
+        # For consumption by common modules
+        type = "home";
       };
     };
   };

modules/nixos/profiles/bluetooth/default.nix

@@ -1,15 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.profiles.bluetooth;
-in
-{
-  options.my.profiles.bluetooth = with lib; {
-    enable = mkEnableOption "bluetooth profile";
-  };
-
-  config = lib.mkIf cfg.enable {
-    my.hardware.bluetooth.enable = true;
-
-    my.home.bluetooth.enable = true;
-  };
-}

modules/nixos/profiles/default.nix

@@ -1,12 +0,0 @@
-# Configuration that spans accross system and home, or are almagations of modules
-{ ... }:
-{
-  imports = [
-    ./bluetooth
-    ./devices
-    ./gtk
-    ./laptop
-    ./wm
-    ./x
-  ];
-}

modules/nixos/profiles/devices/default.nix

@@ -1,20 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.profiles.devices;
-in
-{
-  options.my.profiles.devices = with lib; {
-    enable = mkEnableOption "devices profile";
-  };
-
-  config = lib.mkIf cfg.enable {
-    my.hardware = {
-      ergodox.enable = true;
-
-      mx-ergo.enable = true;
-    };
-
-    # MTP devices auto-mount via file explorers
-    services.gvfs.enable = true;
-  };
-}

modules/nixos/profiles/gtk/default.nix

@@ -1,17 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.profiles.gtk;
-in
-{
-  options.my.profiles.gtk = with lib; {
-    enable = mkEnableOption "gtk profile";
-  };
-
-  config = lib.mkIf cfg.enable {
-    # Allow setting GTK configuration using home-manager
-    programs.dconf.enable = true;
-
-    # GTK theme configuration
-    my.home.gtk.enable = true;
-  };
-}

modules/nixos/profiles/laptop/default.nix

@@ -1,23 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.profiles.laptop;
-in
-{
-  options.my.profiles.laptop = with lib; {
-    enable = mkEnableOption "laptop profile";
-  };
-
-  config = lib.mkIf cfg.enable {
-    # Enable touchpad support
-    services.xserver.libinput.enable = true;
-
-    # Enable TLP power management
-    my.services.tlp.enable = true;
-
-    # Enable upower power management
-    my.hardware.upower.enable = true;
-
-    # Enable battery notifications
-    my.home.power-alert.enable = true;
-  };
-}

modules/nixos/profiles/wm/default.nix

@@ -1,29 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.profiles.wm;
-in
-{
-  options.my.profiles.wm = with lib; {
-    windowManager = mkOption {
-      type = with types; nullOr (enum [ "i3" ]);
-      default = null;
-      example = "i3";
-      description = "Which window manager to use";
-    };
-  };
-
-  config = lib.mkMerge [
-    (lib.mkIf (cfg.windowManager == "i3") {
-      # Enable i3
-      services.xserver.windowManager.i3.enable = true;
-      # i3 settings
-      my.home.wm.windowManager = "i3";
-      # Screenshot tool
-      my.home.flameshot.enable = true;
-      # Auto disk mounter
-      my.home.udiskie.enable = true;
-      # udiskie fails if it can't find this dbus service
-      services.udisks2.enable = true;
-    })
-  ];
-}

modules/nixos/profiles/x/default.nix

@@ -1,23 +0,0 @@
-{ config, lib, pkgs, ... }:
-let
-  cfg = config.my.profiles.x;
-in
-{
-  options.my.profiles.x = with lib; {
-    enable = mkEnableOption "X profile";
-  };
-
-  config = lib.mkIf cfg.enable {
-    # Enable the X11 windowing system.
-    services.xserver.enable = true;
-    # Nice wallpaper
-    services.xserver.displayManager.lightdm.background =
-      let
-        wallpapers = "${pkgs.plasma5Packages.plasma-workspace-wallpapers}/share/wallpapers";
-      in
-      "${wallpapers}/summer_1am/contents/images/2560x1600.jpg";
-
-    # X configuration
-    my.home.x.enable = true;
-  };
-}