Refactor nixos/home configs generation

Expand facts and filter supported systems before
feeding list to generator functions.

flake.nix

@@ -33,7 +33,9 @@
   let
     lib = import ./lib { inherit inputs; };
     inherit (import ./secrets/build/facts.nix {}) facts;
-    inherit (lib) forAllSystems buildHomeConfigs buildNixosConfigs;
+    inherit (lib) buildHomeConfigs buildNixosConfigs expandFacts filterSystem forAllSystems;
+
+    hosts = expandFacts facts;
 
     local-pkgs = final: _prev: import ./pkgs { pkgs = final; };
 
@@ -47,11 +49,11 @@
   in {
     inherit facts legacyPackages lib;
 
-    nixosConfigurations = buildNixosConfigs facts;
+    nixosConfigurations = buildNixosConfigs (filterSystem "linux" hosts);
     nixosModules = import ./modules/nixos;
     nixosProfiles = import ./modules/profiles;
 
-    homeConfigurations = buildHomeConfigs facts;
+    homeConfigurations = buildHomeConfigs hosts;
     homeModules = import ./modules/home-manager;
 
     devShells = forAllSystems (system: {

lib/default.nix

@@ -2,10 +2,10 @@
 let
   inherit (inputs) self home-manager nixpkgs;
 
-  inherit (builtins) concatStringsSep hashString map pathExists split substring;
-  inherit (nixpkgs.lib) isList nameValuePair nixosSystem optional optionalAttrs;
+  inherit (builtins) concatStringsSep hashString map match pathExists split substring;
+  inherit (nixpkgs.lib) filterAttrs nameValuePair nixosSystem optional optionalAttrs;
   inherit (nixpkgs.lib.misc) mergeAttrsWithFunc;
-  inherit (nixpkgs.lib.lists) flatten remove unique;
+  inherit (nixpkgs.lib.lists) flatten isList remove unique;
   inherit (nixpkgs.lib.attrsets) concatMapAttrs genAttrs listToAttrs mapAttrs;
   inherit (home-manager.lib) homeManagerConfiguration;
 
@@ -16,6 +16,8 @@ let
 
   forAllSystems = genAttrs [ "aarch64-darwin" "aarch64-linux" "x86_64-linux" ];
 
+  filterSystem = system: (filterAttrs (k: v: (match ".*-${system}" v.system) == []));
+
   machineId = hostname: hashString "md5" hostname;
 
   macAddress = hostname: let
@@ -26,31 +28,29 @@ let
 
   setDefaults = mergeAttrsWithFunc (a: b: if isList(a) then (unique (a ++ b)) else b);
 
-  buildNixosConfigs = facts: mapAttrs (hostname: v: let
-    hostFacts = setDefaults facts.defaults v;
-    pkgs = self.legacyPackages.${hostFacts.system};
-    pkgsCross = self.legacyPackages.${facts.defaults.system}.pkgsCross.aarch64-multiplatform;
+  expandFacts = facts: mapAttrs (hostname: v: setDefaults facts.defaults v) facts.hosts;
 
-    extraArgs = { inherit hostFacts; } // optionalAttrs (hostFacts.system == "aarch64-linux") { inherit pkgsCross; };
+  buildNixosConfigs = mapAttrs (hostname: hostFacts: let
+    pkgsCross = optionalAttrs (hostFacts.system == "aarch64-linux")
+                  { pkgsCross = self.legacyPackages.x86_64-linux.pkgsCross.aarch64-multiplatform; };
   in nixosSystem {
-      inherit pkgs;
-      specialArgs = { inherit self inputs hostname secrets; } // extraArgs;
+      pkgs = self.legacyPackages.${hostFacts.system};
+      specialArgs = { inherit self inputs hostname hostFacts secrets; } // pkgsCross;
       modules = [ self.nixosModules.default ../secrets/build/facts.nix ]
                 ++ ifExists ../hosts/${hostname}
                 ++ map (u: ../users/${u}) hostFacts.users;
     }
-  ) facts.hosts;
+  );
 
-  buildHomeConfigs = facts: concatMapAttrs (hostname: v: let
-    hostFacts = setDefaults v facts.defaults;
-    pkgs = self.legacyPackages.${hostFacts.system};
+  buildHomeConfigs = concatMapAttrs (hostname: v: let
+    pkgs = self.legacyPackages.${v.system};
   in listToAttrs (map (username:
       nameValuePair "${username}@${hostname}" (homeManagerConfiguration {
         inherit pkgs;
-        extraSpecialArgs = { inherit inputs username; inherit (hostFacts) stateVersion; };
+        extraSpecialArgs = { inherit inputs username; inherit (v) stateVersion; };
         modules = [ ../users/${username}/home.nix ]
                   ++ ifExists ../users/${username}/${hostname}.nix;
       })
-    ) hostFacts.users)
-  ) facts.hosts;
-in { inherit buildHomeConfigs buildNixosConfigs forAllSystems machineId macAddress; }
+    ) v.users)
+  );
+in { inherit buildHomeConfigs buildNixosConfigs expandFacts filterSystem forAllSystems machineId macAddress; }