Inventory: docs improvements

lib/build-clan/module.nix

@@ -68,7 +68,7 @@ let
           hwConfig = "${directory}/machines/${name}/hardware-configuration.nix";
 
           facterModules = lib.optionals (builtins.pathExists facterJson) [
-            "${clan-core.inputs.nixos-facter-modules}/modules/nixos/facter.nix"
+            clan-core.inputs.nixos-facter-modules.nixosModules.facter
             { config.facter.reportPath = facterJson; }
           ];
         in
@@ -231,6 +231,9 @@ in
         )
       );
     }
+    {
+      inventory.machines = lib.mapAttrs (_n: _: { }) config.machines;
+    }
     # Merge the meta attributes from the buildClan function
     { inventory.meta = if config.meta != null then config.meta else { }; }
   ];

lib/description.nix

@@ -12,7 +12,7 @@ rec {
     in
     readmeContents;
 
-  getShortDescription =
+  getFrontmatter =
     modulename:
     let
       content = getReadme modulename;
@@ -21,14 +21,21 @@ rec {
       parsed = builtins.partition ({ index, ... }: if index >= 2 then false else true) (
         lib.filter ({ index, ... }: index != 0) (lib.imap0 (index: part: { inherit index part; }) parts)
       );
-
-      # Use this if the content is needed
-      # readmeContent = lib.concatMapStrings (v: "---" + v.part) parsed.wrong;
-
       meta = builtins.fromTOML (builtins.head parsed.right).part;
     in
     if (builtins.length parts >= 3) then
-      meta.description
+      meta
     else
-      throw "Short description delimiter `---` not found in README.md for module ${modulename}";
+      throw ''
+        TOML Frontmatter not found in README.md for module ${modulename}
+
+        Please add the following to the top of your README.md:
+
+        ---
+        description = "Your description here"
+        categories = [ "Your categories here" ]
+        features = [ "inventory" ]
+        ---
+        ...rest of your README.md...
+      '';
 }

lib/inventory/build-inventory/assertions.nix

@@ -74,4 +74,5 @@
       ) [ ] config.services;
     }
   ];
+
 }

lib/inventory/build-inventory/default.nix

@@ -37,44 +37,18 @@ let
         ) [ ] members.tags or [ ]);
     };
 
+  checkService =
+    serviceName:
+    let
+      frontmatter = clan-core.lib.modules.getFrontmatter serviceName;
+    in
+    if builtins.elem "inventory" frontmatter.features or [ ] then true else false;
+
   /*
     Returns a NixOS configuration for every machine in the inventory.
 
     machinesFromInventory :: Inventory -> { ${machine_name} :: NixOSConfiguration }
   */
-
-  # { client_1_machine = { tags = [ "backup" ]; }; client_2_machine = { tags = [ "backup" ]; }; not_used_machine = { }; }
-  getAllMachines =
-    inventory:
-    lib.foldlAttrs (
-      res: serviceName: serviceConfigs:
-      (lib.foldlAttrs (
-        res: instanceName: serviceConfig:
-        lib.foldlAttrs (
-          res: roleName: members:
-          let
-            resolved = resolveTags {
-              inherit
-                serviceName
-                instanceName
-                roleName
-                inventory
-                members
-                ;
-            };
-          in
-          res
-          // builtins.listToAttrs (
-            builtins.map (m: {
-              name = m;
-              value = { };
-            }) resolved.machines
-          )
-        ) res serviceConfig.roles
-      ) res serviceConfigs)
-    ) { } (inventory.services or { })
-    // inventory.machines or { };
-
   buildInventory =
     { inventory, directory }:
     # For every machine in the inventory, build a NixOS configuration
@@ -178,7 +152,7 @@ let
             ]
           else
             acc2
-        ) [ ] serviceConfigs)
+        ) [ ] (serviceConfigs))
       ) [ ] inventory.services
       # Append each machine config
       ++ [
@@ -188,9 +162,35 @@ let
         (lib.optionalAttrs (machineConfig.deploy.targetHost or null != null) {
           config.clan.core.networking.targetHost = machineConfig.deploy.targetHost;
         })
+        {
+          assertions = lib.foldlAttrs (
+            acc: serviceName: _:
+            acc
+            ++ [
+              {
+                assertion = checkService serviceName;
+                message = ''
+                  Service ${serviceName} cannot be used in inventory. It does not declare the 'inventory' feature.
+
+
+                          To allow it add the following to the beginning of the README.md of the module:
+
+                            ---
+                            ...
+
+                            features = [ "inventory" ]
+                            ---
+
+                          Also make sure to test the module with the 'inventory' feature enabled.
+
+                '';
+              }
+            ]
+          ) [ ] inventory.services;
+        }
       ]
-    ) (getAllMachines inventory);
+    ) inventory.machines;
 in
 {
-  inherit buildInventory getAllMachines;
+  inherit buildInventory;
 }

lib/inventory/tests/default.nix

@@ -1,37 +1,8 @@
 { inventory, clan-core, ... }:
 let
-  inherit (inventory) buildInventory getAllMachines;
+  inherit (inventory) buildInventory;
 in
 {
-  test_get_all_used_machines = {
-    # Test that all machines are returned
-    expr = getAllMachines {
-      machines = {
-        machine_3 = {
-          tags = [ "tag_3" ];
-        };
-      };
-      services = {
-        borgbackup.instance_1 = {
-          roles.server.machines = [ "backup_server" ];
-          roles.client.machines = [
-            "client_1_machine"
-            "client_2_machine"
-          ];
-          roles.client.tags = [ "tag_3" ];
-        };
-      };
-    };
-    expected = {
-      backup_server = { };
-      client_1_machine = { };
-      client_2_machine = { };
-      machine_3 = {
-        tags = [ "tag_3" ];
-      };
-    };
-  };
-
   test_inventory_empty = {
     # Empty inventory should return an empty module
     expr = buildInventory {