templates/new-clan: auto load all machines from ./machines

templates/new-clan/clan-flake-module.nix

@@ -1,9 +1,52 @@
 # AUTOMATICALLY GENERATED by clan
-{ ... }: {
+# TODO: move this code to a flakeModule in clan-core and import it via flake input
+{ self, lib, inputs, ... }:
+let
+  evalConfig = import (self.inputs.nixpkgs + /lib/eval-config.nix);
+
+  evalMachine = machineModule: evalConfig {
+    modules = [ machineModule ];
+  };
+
+  machinesDirs =
+    if builtins.pathExists ./machines
+    then builtins.readDir ./machines
+    else { };
+
+  machineSettings = machineName:
+    if builtins.pathExists ./machines/${machineName}/settings.json
+    then (builtins.fromJSON (builtins.readFile ./machines/${machineName}/settings.json))
+    else { };
+
+  # load all clan modules by default
+  machineModule = machineName: {
+    imports =
+      (lib.attrValues inputs.clan.clanModules)
+      ++ [ (machineSettings machineName) ];
+  };
+
+  # autoamtically generate machine modules for all directories under ./machines
+  machineModulesGenerated =
+    lib.flip lib.mapAttrs' machinesDirs (name: _: {
+      name = "machine-${name}";
+      value = machineModule name;
+    });
+
+  # re-read the machine modules from the flake outputs, to allow amchines being
+  # defined by custom mechanisms
+  machineModules =
+    lib.filterAttrs (name: _: lib.hasPrefix "machine-" name) self.nixosModules;
+
+in
+{
   imports =
     let
       relPaths = builtins.fromJSON (builtins.readFile ./imports.json);
       paths = map (path: ./. + path) relPaths;
     in
     paths;
+  flake.nixosModules = machineModulesGenerated;
+  # generate nixosConfigurations for all machines under self.nixosModules.machines-{machine_name}
+  flake.nixosConfigurations =
+    lib.mapAttrs (_: mod: evalMachine mod) machineModules;
 }