chore(inventory/services): dont check _class of legacy clanModules.

Let the module system handle the error. Once we shift to deferred
modules, things get more complicated and we cannot check the module
class eagerly

lib/inventory/build-inventory/builder/default.nix

@@ -56,7 +56,7 @@ let
       assertions = { };
     };
 
-  legacyResolveImports =
+  resolveImports =
     {
       supportedRoles,
       resolvedRolesPerInstance,
@@ -168,27 +168,7 @@ in
                 ./roles.nix
               ];
 
-              isClanModule =
-                let
-                  firstRole = import (getRoleFile (builtins.head config.supportedRoles));
-                  loadModuleForClassCheck =
-                    m:
-                    if lib.isFunction m then
-                      let
-                        args = lib.functionArgs m;
-                      in
-                      m args
-                    else
-                      m;
-                  module = loadModuleForClassCheck (firstRole);
-                in
-                if (module) ? _class then module._class == "clan" else false;
-              # The actual result
-              machineImports =
-                if config.isClanModule then
-                  throw "Clan modules are not supported yet."
-                else
-                  legacyResolveImports {
+              machineImports = resolveImports {
                 supportedRoles = config.supportedRoles;
                 resolvedRolesPerInstance = config.resolvedRolesPerInstance;
                 inherit

lib/inventory/build-inventory/builder/interface.nix

@@ -54,9 +54,6 @@ in
                             matchedRoles = mkOption {
                               type = types.listOf types.str;
                             };
-                            isClanModule = mkOption {
-                              type = types.bool;
-                            };
                             machinesRoles = mkOption {
                               type = types.attrsOf (types.listOf types.str);
                             };

lib/inventory/build-inventory/builder/roles.nix

@@ -14,7 +14,7 @@ in
 {
   # Roles resolution
   # : List String
-  supportedRoles = clanLib.modules.getRoles inventory.modules serviceName;
+  supportedRoles = clanLib.modules.getRoles "inventory.modules" inventory.modules serviceName;
   matchedRoles = builtins.attrNames (
     lib.filterAttrs (_: ms: builtins.elem machineName ms) config.machinesRoles
   );

lib/inventory/eval-clan-modules/default.nix

@@ -74,7 +74,7 @@ let
           roles =
             if builtins.elem "inventory" frontmatter.features or [ ] then
               assert lib.isPath module;
-              clanLib.modules.getRoles allModules moduleName
+              clan-core.lib.modules.getRoles "Documentation: inventory.modules" allModules moduleName
             else
               [ ];
         in

lib/inventory/frontmatter/default.nix

@@ -36,7 +36,7 @@ let
     lib.evalModules {
       specialArgs = {
         inherit moduleName resolvedRoles instanceName;
-        allRoles = getRoles allModules moduleName;
+        allRoles = getRoles "inventory.modules" allModules moduleName;
       };
       modules = [
         (getFrontmatter allModules.${moduleName} moduleName)
@@ -56,15 +56,30 @@ let
       ];
     }).options;
 
+  # This is a legacy function
+  # Old modules needed to define their roles by directory
+  # This means if this function gets anything other than a string/path it will throw
   getRoles =
-    allModules: serviceName:
-    lib.mapAttrsToList (name: _value: trimExtension name) (
+    scope: allModules: serviceName:
+    let
+      module =
+        allModules.${serviceName}
+          or (throw "(Legacy) ClanModule not found: '${serviceName}'. Make sure the module is added to ${scope}");
+      moduleType = (lib.typeOf module);
+      checked = if builtins.elem moduleType ["string" "path"] then true else throw "(Legacy) ClanModule must be a 'path' or 'string' pointing to a directory: Got 'typeOf inventory.modules.${serviceName}' => ${moduleType} ";
+      modulePath = lib.seq checked module + "/roles";
+      checkedPath = if builtins.pathExists modulePath then modulePath else throw ''
+        (Legacy) ClanModule must have a 'roles' directory'
+
+        Fixes:
+        - Provide a 'roles' subdirectory
+        - Use the newer 'clan.service' modules. (Recommended)
+      '';
+    in
+    lib.seq checkedPath lib.mapAttrsToList (name: _value: trimExtension name) (
       lib.filterAttrs (name: type: type == "regular" && lib.hasSuffix ".nix" name) (
         builtins.readDir (
-          if allModules ? ${serviceName} then
-            allModules.${serviceName} + "/roles"
-          else
-            throw "ClanModule not found: '${serviceName}'. Make sure the module is added in the 'clanModules' attribute of clan-core."
+          checkedPath
         )
       )
     );