flake.nix/refactor: unify common logic

flake.nix

@@ -65,127 +65,87 @@
     }:
     let
       pkgs = nixpkgs.legacyPackages.x86_64-linux.pkgs;
+      inherit (nixpkgs) lib;
+
+      # Build a host's nixosConfiguration from the shared boilerplate.
+      # Per-host differences are expressed as flags / extraModules rather
+      # than copy-pasted module blocks.
+      mkHost =
+        { hostname            # name of the ./<hostname> and ./home/<hostname> dirs
+        , system ? "x86_64-linux"
+        , homeHost ? hostname # which home/<...> config to use (iso reuses nixy)
+        , packages ? true     # import common/packages.nix
+        , suspend ? true      # import common/suspend.nix
+        , hardware ? true     # import <hostname>/hardware-configuration.nix
+        , sops ? true          # wire sops-nix
+        , hm ? true            # wire home-manager
+        , hmBackup ? true     # set home-manager.backupFileExtension
+        , nixosLib ? nixpkgs.lib  # nixosSystem source (iso uses `nixos`)
+        , extraModules ? [ ]
+        }:
+        nixosLib.nixosSystem {
+          inherit system;
+          modules =
+            [
+              { _module.args = inputs; }
+              { _module.args.system = system; }
+              { nix.registry.nixpkgs.flake = nixpkgs; }
+            ]
+            ++ lib.optional packages ./common/packages.nix
+            ++ lib.optional suspend ./common/suspend.nix
+            ++ [ (./. + "/${hostname}/configuration.nix") ]
+            ++ lib.optional hardware (./. + "/${hostname}/hardware-configuration.nix")
+            ++ lib.optional sops sops-nix.nixosModules.sops
+            ++ lib.optionals hm [
+              home-manager.nixosModules.home-manager
+              {
+                home-manager.useGlobalPkgs = true;
+                home-manager.useUserPackages = true;
+                home-manager.users.akill = import (./home + "/${homeHost}/home.nix");
+                home-manager.extraSpecialArgs = { inherit inputs system; };
+              }
+            ]
+            ++ lib.optional (hm && hmBackup) { home-manager.backupFileExtension = "home_backup"; }
+            ++ extraModules;
+        };
     in
     {
       nixosConfigurations = {
-        nixy = nixpkgs.lib.nixosSystem rec {
+        nixy = mkHost { hostname = "nixy"; };
-          system = "x86_64-linux";
-          modules = [
-            { _module.args = inputs; }
-            { _module.args.system = system; }
-            { nix.registry.nixpkgs.flake = nixpkgs; }
-            ./common/packages.nix
-            ./common/suspend.nix
-            ./nixy/configuration.nix
-            ./nixy/hardware-configuration.nix
-            sops-nix.nixosModules.sops
-            home-manager.nixosModules.home-manager
-            {
-              home-manager.useGlobalPkgs = true;
-              home-manager.useUserPackages = true;
-              home-manager.users.akill = import ./home/nixy/home.nix;
-              home-manager.extraSpecialArgs = { inherit inputs system; };
-              home-manager.backupFileExtension = "home_backup";
-            }
-          ];
-        };
 
-        fuji = nixpkgs.lib.nixosSystem rec {
+        fuji = mkHost { hostname = "fuji"; };
-          system = "x86_64-linux";
-          modules = [
-            { _module.args = inputs; }
-            { _module.args.system = system; }
-            { nix.registry.nixpkgs.flake = nixpkgs; }
-            ./common/packages.nix
-            ./common/suspend.nix
-            ./fuji/configuration.nix
-            ./fuji/hardware-configuration.nix
-            sops-nix.nixosModules.sops
-            home-manager.nixosModules.home-manager
-            {
-              home-manager.useGlobalPkgs = true;
-              home-manager.useUserPackages = true;
-              home-manager.users.akill = import ./home/fuji/home.nix;
-              home-manager.extraSpecialArgs = { inherit inputs system; };
-              home-manager.backupFileExtension = "home_backup";
-            }
-          ];
-        };
 
-        nixy_iso = nixos.lib.nixosSystem rec {
+        nixy_iso = mkHost {
-          system = "x86_64-linux";
+          hostname = "nixy";
-          modules = [
+          hardware = false;
-            { _module.args = inputs; }
+          nixosLib = nixos.lib;
-            { _module.args.system = system; }
+          extraModules = [
-            { nix.registry.nixpkgs.flake = nixpkgs; }
             { isoImage.squashfsCompression = "gzip -Xcompression-level 1"; }
-            ./common/packages.nix
-            ./common/suspend.nix
-            ./nixy/configuration.nix
             "${nixos}/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix"
-            sops-nix.nixosModules.sops
-            home-manager.nixosModules.home-manager
-            {
-              home-manager.useGlobalPkgs = true;
-              home-manager.useUserPackages = true;
-              home-manager.users.akill = import ./home/nixy/home.nix;
-              home-manager.extraSpecialArgs = { inherit inputs system; };
-              home-manager.backupFileExtension = "home_backup";
-            }
           ];
         };
 
-        mediabox = nixpkgs.lib.nixosSystem rec {
+        mediabox = mkHost {
-          system = "x86_64-linux";
+          hostname = "mediabox";
-          modules = [
+          hmBackup = false;
-            { _module.args = inputs; }
+          extraModules = [ ./modules/qbittorrent.nix ];
-            { _module.args.system = system; }
-            { nix.registry.nixpkgs.flake = nixpkgs; }
-            ./common/packages.nix
-            ./common/suspend.nix
-            ./mediabox/configuration.nix
-            ./mediabox/hardware-configuration.nix
-            ./modules/qbittorrent.nix
-            sops-nix.nixosModules.sops
-            home-manager.nixosModules.home-manager
-            {
-              home-manager.useGlobalPkgs = true;
-              home-manager.useUserPackages = true;
-              home-manager.users.akill = import ./home/mediabox/home.nix;
-              home-manager.extraSpecialArgs = { inherit inputs system; };
-            }
-          ];
         };
 
-        blue = nixpkgs.lib.nixosSystem rec {
+        blue = mkHost {
-          system = "x86_64-linux";
+          hostname = "blue";
-          modules = [
+          suspend = false;
-            { _module.args = inputs; }
+          sops = false;
-            { _module.args.system = system; }
+          hmBackup = false;
-            { nix.registry.nixpkgs.flake = nixpkgs; }
-            ./blue/configuration.nix
-            ./blue/hardware-configuration.nix
-            ./common/packages.nix
-            home-manager.nixosModules.home-manager
-            {
-              home-manager.useGlobalPkgs = true;
-              home-manager.useUserPackages = true;
-              home-manager.users.akill = import ./home/blue/home.nix;
-              home-manager.extraSpecialArgs = { inherit inputs system; };
-            }
-          ];
         };
 
-        magpie = nixpkgs.lib.nixosSystem rec {
+        magpie = mkHost {
+          hostname = "magpie";
           system = "aarch64-linux";
-          modules = [
+          packages = false;
-            { _module.args = inputs; }
+          suspend = false;
-            { _module.args.system = system; }
+          hm = false;
-            { nix.registry.nixpkgs.flake = nixpkgs; }
+          extraModules = [
-            ./magpie/configuration.nix
-            ./magpie/hardware-configuration.nix
             simple-nixos-mailserver.nixosModule
-            sops-nix.nixosModules.sops
             (builtins.toPath "${nixpkgs}/nixos/modules/profiles/qemu-guest.nix")
           ];
         };