deps: init poc

clanServices/hello-world/default.nix

@@ -3,13 +3,20 @@
 
 # The test for this module in ./tests/vm/default.nix shows an example of how
 # the service is used.
-
-{ packages }:
-{ ... }:
+{ ... }@service:
 {
   _class = "clan.service";
-  manifest.name = "clan-core/hello-word";
+  manifest.name = "clan-core/hello-world";
   manifest.description = "This is a test";
+  manifest.dependencies = {
+    #
+    home-manager = {
+      recomendedUrl = "github:nix-community/home-manager/release-25.05";
+    };
+  };
+
+  # Declare dependencies that the user must provide via flake inputs
+  # Or via 'clan.serviceOverrides.<manifest-name>.dependencies.resolved
 
   # This service provides two roles: "morning" and "evening". Roles can be
   # defined in this file directly (e.g. the "morning" role) or split up into a

clanServices/hello-world/flake-module.nix

@@ -5,9 +5,7 @@
   ...
 }:
 let
-  module = lib.modules.importApply ./default.nix {
-    inherit (self) packages;
-  };
+  module = ./default.nix;
 in
 {
   clan.modules = {

flake.nix

@@ -66,7 +66,39 @@
         };
         clan = {
           meta.name = "clan-core";
+
+          modules = {
+            myModule = { ... }: {
+              #
+              _module.args = { inherit inputs; };
+            };
+
+            # # depends on home-manager 25.05
+            # myEnzime = { ... }: {
+            #   imports = [ inputs.enzime.yours ];
+            #   dependencies.home-manager = lib.mkForce "my-home-manager";
+            # };
+            # # depends on home-manager 24.05
+            # myLassulus = { ... }: {
+            #   imports = [ inputs.lassulus.his ];
+            #   dependencies.home-manager = lib.mkForce "my-home-manager";
+            # };
+          };
+
+
+          serviceOverrides = {
+            "clan-core/hello-world" = {
+              dependencies = {
+                flake-parts = "flake-parts";
+              };
+            };
+          };
+
           inventory = {
+            instances.hello-world = {
+              roles.morning.tags = [ "all" ];
+            };
+
             machines = {
               "test-darwin-machine" = {
                 machineClass = "darwin";

lib/modules/clan/interface.nix

@@ -228,6 +228,38 @@ in
       '';
     };
 
+    serviceOverrides = lib.mkOption {
+      type = types.attrsOf (types.submoduleWith {
+        modules = [
+          {
+            options.dependencies = lib.mkOption {
+              type = types.attrsOf types.raw;
+              description = "Override a dependencies of this service";
+            };
+          }
+        ];
+      });
+      default = { };
+      description = ''
+        Override/inject dependencies to a service.
+
+        Example:
+
+        ```nix
+        {
+          servicesOverrides = {
+            # Override need to be done by manifest name to avoid ambiguity
+            "clan-core/hello-world" = {
+              dependencies = {
+                home-manager = inputs.home-manager-v2;
+              };
+            };
+          };
+        }
+        ```
+      '';
+    };
+
     inventory = lib.mkOption {
       type = types.submoduleWith {
         modules = [

lib/modules/clan/module.nix

@@ -248,7 +248,7 @@ in
                 staticModules = clan-core.clan.modules;
 
                 distributedServices = clanLib.inventory.mapInstances {
-                  inherit (clanConfig) inventory exportsModule;
+                  inherit (clanConfig) inventory exportsModule serviceOverrides;
                   inherit flakeInputs directory;
                   clanCoreModules = clan-core.clan.modules;
                   prefix = [ "distributedServices" ];

lib/modules/inventory/distributed-service/all-services-wrapper.nix

@@ -2,6 +2,7 @@
 {
   # TODO: consume directly from clan.config
   directory,
+  serviceOverrides,
 }:
 {
   lib,
@@ -31,10 +32,12 @@ in
             (
               { name, ... }:
               {
-                _module.args._ctx = [ name ];
-                _module.args.exports = config.exports;
-                _module.args.directory = directory;
-
+                _module.args = {
+                  _ctx = [ name ];
+                  exports = config.exports;
+                  directory = directory;
+                  inherit (specialArgs) clanLib _unsafe;
+                };
               }
             )
             ./service-module.nix
@@ -43,6 +46,9 @@ in
               inherit (specialArgs) clanLib;
               prefix = _ctx;
             })
+            (service: {
+              dependencies = lib.mapAttrs (n: v: { resolved = v; }) serviceOverrides.${service.config.manifest.name}.dependencies or { };
+            })
           ];
         };
       };

lib/modules/inventory/distributed-service/inventory-adapter.nix

@@ -26,8 +26,9 @@ in
       inventory,
       directory,
       clanCoreModules,
-      prefix ? [ ],
       exportsModule,
+      prefix ? [ ],
+      serviceOverrides ? { },
     }:
     let
       # machineHasTag = machineName: tagName: lib.elem tagName inventory.machines.${machineName}.tags;
@@ -127,9 +128,10 @@ in
           specialArgs = {
             inherit clanLib;
             _ctx = prefix;
+            _unsafe.flakeInputs = flakeInputs;
           };
           modules = [
-            (import ./all-services-wrapper.nix { inherit directory; })
+            (import ./all-services-wrapper.nix { inherit directory serviceOverrides; })
           ]
           ++ modules;
         };

lib/modules/inventory/distributed-service/service-module.nix

@@ -2,6 +2,7 @@
   lib,
   config,
   _ctx,
+  _unsafe,
   directory,
   exports,
   ...
@@ -106,6 +107,10 @@ let
 in
 {
   options = {
+
+    debug = mkOption {
+      default = _unsafe.flakeInputs;
+    };
     # Option to disable some behavior during docs rendering
     _docs_rendering = mkOption {
       default = false;
@@ -113,6 +118,54 @@ in
       type = types.bool;
     };
 
+    dependencies = mkOption {
+      type = types.attrsWith {
+        placeholder = "dependencyName";
+        elemType = types.submoduleWith {
+          modules = [
+            ({name,...}@dep: {
+              options.name = mkOption {
+                default = name;
+                type = types.str;
+                description = "The name of the dependency, usually the input name.";
+              };
+              options.resolved = mkOption {
+                type = types.raw;
+                default = _unsafe.flakeInputs.${dep.config.name} or (throw ''
+                  The dependency '${dep.config.name}' could not be found in the flake inputs.
+
+                  This module requires '${dep.config.name}' to be present
+                  Fixes:
+                  - Add '${dep.config.name}' to the flake inputs
+                  - Inject a custom dependency via 'clan.serviceOverrides.<manifest-name>.dependencies.${dep.config.name} = ...'
+                '');
+                description = ''
+                  The resolved value of the dependency.
+                '';
+              };
+            })
+          ];
+        };
+      };
+      description = ''
+        Dependencies of this service.
+
+        Can be declared via `clan.lib.mkDependency`.
+
+        ```nix
+        {
+          home-manager = clan.lib.mkDependency {
+            name = "home-manager";
+          };
+        }
+        ```
+
+        This will map `inputs.home-manager` to `dependencies.home-manager`.
+        The dependency can then be safely accessed via `config.dependencies.home-manager` from the toplevel arguments of this module.
+      '';
+      default = { };
+    };
+
     instances = mkOption {
       visible = false;
       defaultText = "Throws: 'The service must define its instances' when not defined";