Exports POC

lib/default.nix

@@ -40,6 +40,9 @@ lib.fix (
       # TODO: Flatten our lib functions like this:
       resolveModule = clanLib.callLib ./resolve-module { };
 
+      # Functions to help define exports
+      exports = clanLib.callLib ./exports.nix { };
+
       fs = {
         inherit (builtins) pathExists readDir;
       };

lib/exports.nix

@@ -0,0 +1,88 @@
+{ lib }:
+let
+  /**
+    Creates a scope string for global exports
+
+    At least one of serviceName or machineName must be set.
+
+    The scope string has the format:
+
+    "/SERVICE/INSTANCE/ROLE/MACHINE"
+
+    If the parameter is not set, the corresponding part is left empty.
+    Semantically this means "all".
+
+    Examples:
+    mkScope { serviceName = "A"; }
+    -> "/A///"
+
+    mkScope { machineName = "jon"; }
+    -> "///jon"
+
+    mkScope { serviceName = "A"; instanceName = "i1"; roleName = "peer"; machineName = "jon"; }
+    -> "/A/i1/peer/jon"
+  */
+  mkScope =
+    {
+      serviceName ? "",
+      instanceName ? "",
+      roleName ? "",
+      machineName ? "",
+    }:
+    let
+      parts = [
+        serviceName
+        instanceName
+        roleName
+        machineName
+      ];
+      checkedParts = lib.map (
+        part:
+        lib.throwIf (builtins.match ".?/.?" part != null) ''
+          clanLib.exports.mkScope: ${part} cannot contain the "/" character
+        ''
+      ) parts;
+    in
+    lib.throwIf ((serviceName == "" && machineName == "")) ''
+      clanLib.exports.mkScope requires at least 'serviceName' or 'machineName' to be set
+
+      In case your use case requires neither
+    '' (lib.join "/" checkedParts);
+
+  /**
+    Parses a scope string into its components
+
+    Returns an attribute set with the keys:
+    - serviceName
+    - instanceName
+    - roleName
+    - machineName
+
+    Example:
+    parseScope "A/i1/peer/jon"
+    ->
+    {
+      serviceName = "A";
+      instanceName = "i1";
+      roleName = "peer";
+      machineName = "jon";
+    }
+  */
+  parseScope =
+    scopeStr:
+    let
+      parts = lib.splitString "/" scopeStr;
+      checkedParts = lib.throwIf (lib.length parts != 4) ''
+        clanLib.exports.parseScope: invalid scope string format, expected 4 parts separated by 3 "/"
+      '' (parts);
+    in
+    {
+      serviceName = lib.elemAt 0 checkedParts;
+      instanceName = lib.elemAt 1 checkedParts;
+      roleName = lib.elemAt 2 checkedParts;
+      machineName = lib.elemAt 3 checkedParts;
+    };
+in
+{
+  inherit mkScope parseScope;
+}

lib/flake-module.nix

@@ -103,6 +103,11 @@ rec {
         inherit lib;
         clan-core = self;
       };
+      # Run: nix-unit --extra-experimental-features flakes --flake .#legacyPackages.x86_64-linux.evalTests-build-clan
+      legacyPackages.eval-exports = import ./new_exports.nix {
+        inherit lib;
+        clan-core = self;
+      };
       checks = {
         eval-lib-build-clan = pkgs.runCommand "tests" { nativeBuildInputs = [ pkgs.nix-unit ]; } ''
           export HOME="$(realpath .)"

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

@@ -2,6 +2,7 @@
 {
   # TODO: consume directly from clan.config
   directory,
+  exports,
 }:
 {
   lib,
@@ -17,10 +18,10 @@ in
 {
   # TODO: merge these options into clan options
   options = {
-    exportsModule = mkOption {
+    # exportsModule = mkOption {
-      type = types.deferredModule;
+    #   type = types.deferredModule;
-      readOnly = true;
+    #   readOnly = true;
-    };
+    # };
     mappedServices = mkOption {
       visible = false;
       type = attrsWith {
@@ -28,9 +29,11 @@ in
         elemType = submoduleWith {
           class = "clan.service";
           specialArgs = {
-            directory = directory;
             clanLib = specialArgs.clanLib;
-            exports = config.exports;
+            inherit
+              exports
+              directory
+              ;
           };
           modules = [
             (
@@ -51,34 +54,13 @@ in
       default = { };
     };
     exports = mkOption {
-      type = submoduleWith {
+      type = types.lazyAttrsOf types.deferredModule;
-        modules = [
+
-          {
+      # collect exports from all services
-            options = {
+      # zipAttrs is needed until we use the record type.
-              instances = lib.mkOption {
+      default = lib.zipAttrsWith (_name: values: { imports = values; }) (
-                default = { };
+        lib.mapAttrsToList (_name: service: service.exports) config.mappedServices
-                # instances.<instanceName>...
+      );
-                type = types.attrsOf (submoduleWith {
-                  modules = [
-                    config.exportsModule
-                  ];
-                });
-              };
-              # instances.<machineName>...
-              machines = lib.mkOption {
-                default = { };
-                type = types.attrsOf (submoduleWith {
-                  modules = [
-                    config.exportsModule
-                  ];
-                });
-              };
-            };
-          }
-        ]
-        ++ lib.mapAttrsToList (_: service: service.exports) config.mappedServices;
-      };
-      default = { };
     };
   };
 }

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

@@ -504,7 +504,7 @@ in
                     staticModules = [
                       ({
                         options.exports = mkOption {
-                          type = types.deferredModule;
+                          type = types.lazyAttrsOf types.deferredModule;
                           default = { };
                           description = ''
                             !!! Danger "Experimental Feature"
@@ -634,8 +634,16 @@ in
       type = types.deferredModuleWith {
         staticModules = [
           ({
+            # exports."///".generator.name = { _file ... import = []; _type = }
+            # exports."///".networking = { _file ... import = []; }
+
+            # generators."///".name = { name, ...}: { _file ... import = [];}
+            # networks."///" = { _file ... import = []; }
+
+            # { _file ... import = []; }
+            # { _file ... import = []; }
             options.exports = mkOption {
-              type = types.deferredModule;
+              type = types.lazyAttrsOf types.deferredModule;
               default = { };
               description = ''
                 !!! Danger "Experimental Feature"
@@ -767,79 +775,38 @@ in
         ```
       '';
       default = { };
-      type = types.submoduleWith {
+      type = types.lazyAttrsOf (
-        # Static modules
+        types.deferredModuleWith {
-        modules = [
+          # staticModules = [];
-          {
+          # lib.concatLists (
-            options.instances = mkOption {
+          #   lib.concatLists (
-              type = types.attrsOf types.deferredModule;
+          #     lib.mapAttrsToList (
-              description = ''
+          #       _roleName: role:
-                export modules defined in 'perInstance'
+          #       lib.mapAttrsToList (
-                mapped to their instance name
+          #         _instanceName: instance: lib.mapAttrsToList (_machineName: v: v.exports) instance.allMachines
-
+          #       ) role.allInstances
-                Example
+          #     ) config.result.allRoles
-
+          #   )
-                with instances:
+          # )
-
+          # ++
-                ```nix
-                instances.A = { ... };
-                instances.B= { ... };
-
-                roles.peer.perInstance = { instanceName, machine, ... }:
-                {
-                  exports.foo = 1;
         }
-
+      );
-                This yields all other services can access these exports
+      #     # Lazy default via imports
-                =>
+      #     # should probably be moved to deferredModuleWith { staticModules = [ ]; }
-                exports.instances.A.foo = 1;
+      #     imports =
-                exports.instances.B.foo = 1;
+      #       if config._docs_rendering then
-                ```
+      #         [ ]
-              '';
+      #       else
-            };
+      #         lib.mapAttrsToList (_roleName: role: {
-            options.machines = mkOption {
+      #           instances = lib.mapAttrs (_instanceName: instance: {
-              type = types.attrsOf types.deferredModule;
+      #             imports = lib.mapAttrsToList (_machineName: v: v.exports) instance.allMachines;
-              description = ''
+      #           }) role.allInstances;
-                export modules defined in 'perMachine'
+      #         }) config.result.allRoles
-                mapped to their machine name
+      #         ++ lib.mapAttrsToList (machineName: machine: {
-
+      #           machines.${machineName} = machine.exports;
-                Example
+      #         }) config.result.allMachines;
-
+      #   }
-                with machines:
+      # ];
-
-                ```nix
-                instances.A = { roles.peer.machines.jon = ... };
-                instances.B = { roles.peer.machines.jon = ... };
-
-                perMachine = { machine, ... }:
-                {
-                  exports.foo = 1;
-                }
-
-                This yields all other services can access these exports
-                =>
-                exports.machines.jon.foo = 1;
-                exports.machines.sara.foo = 1;
-                ```
-              '';
-            };
-            # Lazy default via imports
-            # should probably be moved to deferredModuleWith { staticModules = [ ]; }
-            imports =
-              if config._docs_rendering then
-                [ ]
-              else
-                lib.mapAttrsToList (_roleName: role: {
-                  instances = lib.mapAttrs (_instanceName: instance: {
-                    imports = lib.mapAttrsToList (_machineName: v: v.exports) instance.allMachines;
-                  }) role.allInstances;
-                }) config.result.allRoles
-                ++ lib.mapAttrsToList (machineName: machine: {
-                  machines.${machineName} = machine.exports;
-                }) config.result.allMachines;
-          }
-        ];
-      };
     };
     # ---
     # Place the result in _module.result to mark them as "internal" and discourage usage/overrides
@@ -1024,5 +991,39 @@ in
         }
       ) config.result.allMachines;
     };
+
+    debug = mkOption {
+      default = lib.zipAttrsWith (_name: values: { imports = values; }) (
+        lib.mapAttrsToList (_machineName: machine: machine.exports) config.result.allMachines
+      );
     };
+  };
+
+  imports = [
+    {
+      # collect exports from all machines
+      # zipAttrs is needed until we use the record type.
+      exports = lib.zipAttrsWith (_name: values: { imports = values; }) (
+        lib.mapAttrsToList (_machineName: machine: machine.exports) config.result.allMachines
+      );
+
+    }
+    {
+      # collect exports from all instances, roles and machines
+      # zipAttrs is needed until we use the record type.
+      exports = lib.zipAttrsWith (_name: values: { imports = values; }) (
+        lib.concatLists (
+          lib.concatLists (
+            lib.mapAttrsToList (
+              _roleName: role:
+              lib.mapAttrsToList (
+                _instanceName: instance: lib.mapAttrsToList (_machineName: v: v.exports) instance.allMachines
+              ) role.allInstances
+            ) config.result.allRoles
+          )
+        )
+      );
+    }
+  ];
+
 }

lib/new_exports.nix

@@ -0,0 +1,221 @@
+{
+  clan-core,
+  lib,
+}:
+# TODO: TEST: define a clan without machines
+{
+  test_simple =
+    let
+      eval = clan-core.clanLib.clan {
+        exports."///".foo = lib.mkForce eval.config.exports."///".bar;
+
+        directory = ./.;
+        self = {
+          clan = eval.config;
+          inputs = { };
+        };
+
+        machines.jon = { };
+        machines.sara = { };
+
+        exportsModule =
+          { lib, ... }:
+          {
+            options.foo = lib.mkOption {
+              type = lib.types.number;
+              default = 0;
+            };
+            options.bar = lib.mkOption {
+              type = lib.types.number;
+              default = 0;
+            };
+          };
+
+        ####### Service module "A"
+        modules.service-A =
+          { ... }:
+          {
+            # config.exports
+            manifest.name = "A";
+
+            roles.default = {
+              # TODO: Remove automapping
+              # Currently exports are automapped
+              # scopes "/service=A/instance=hello/role=default/machine=jon"
+              # perInstance.exports.foo = 7;
+
+              # New style:
+              # Explizit scope
+              # perInstance.exports."service=A/instance=hello/role=default/machine=jon".foo = 7;
+              perInstance =
+                { instanceName, machine, exports, ... }:
+                {
+                  exports."A/${instanceName}/default/${machine.name}" = {
+                    foo = 7;
+                    # define export depending on B
+                    bar = exports."B/B/default/${machine.name}".foo + 35;
+                  };
+                  # exports."A/${instanceName}/default/${machine.name}".
+
+                  # default behavior
+                  # exports = scope.mkExports { foo = 7; };
+
+                  # We want to export things for different scopes from this scope;
+                  # If this scope is used.
+                  #
+                  # Explicit scope; different from the function scope above
+                  # exports = clanLib.scopedExport {
+                  #   # Different role export
+                  #   role = "peer";
+                  #   serviceName = config.manifest.name;
+                  #   inherit instanceName machineName;
+                  # } { foo = 7; };
+                };
+            };
+
+            perMachine =
+              { ... }:
+              {
+                #
+                # exports = scope.mkExports { foo = 7; };
+                # exports."A///${machine.name}".foo = 42;
+                # exports."B///".foo = 42;
+              };
+
+            # scope "/service=A/instance=??/role=??/machine=jon"
+            # perMachine.exports.foo = 42;
+
+            # scope "/service=A/instance=??/role=??/machine=??"
+            # exports."///".foo = 10;
+          };
+        ####### Service module "A"
+        modules.service-B =
+          { exports, ... }:
+          {
+            # config.exports
+            manifest.name = "B";
+
+            roles.default = {
+              # TODO: Remove automapping
+              # Currently exports are automapped
+              # scopes "/service=A/instance=hello/role=default/machine=jon"
+              # perInstance.exports.foo = 7;
+
+              # New style:
+              # Explizit scope
+              # perInstance.exports."service=A/instance=hello/role=default/machine=jon".foo = 7;
+              perInstance =
+                { instanceName, machine, ... }:
+                {
+                  # TODO: Test non-existing scope
+                  # define export depending on A
+                  exports."B/${instanceName}/default/${machine.name}".foo = exports."///".foo + exports."A/A/default/${machine.name}".foo;
+                  # exports."B/B/default/jon".foo = exports."A/A/default/jon".foo;
+
+                  # default behavior
+                  # exports = scope.mkExports { foo = 7; };
+
+                  # We want to export things for different scopes from this scope;
+                  # If this scope is used.
+                  #
+                  # Explicit scope; different from the function scope above
+                  # exports = clanLib.scopedExport {
+                  #   # Different role export
+                  #   role = "peer";
+                  #   serviceName = config.manifest.name;
+                  #   inherit instanceName machineName;
+                  # } { foo = 7; };
+                };
+            };
+
+            perMachine =
+              { ... }:
+              {
+                # exports = scope.mkExports { foo = 7; };
+                # exports."A///${machine.name}".foo = 42;
+                # exports."B///".foo = 42;
+              };
+
+            # scope "/service=A/instance=??/role=??/machine=jon"
+            # perMachine.exports.foo = 42;
+
+            # scope "/service=A/instance=??/role=??/machine=??"
+            exports."///".foo = 10;
+          };
+        #######
+
+        inventory = {
+          instances.A = {
+            module.name = "service-A";
+            module.input = "self";
+            roles.default.tags = [ "all" ];
+          };
+          instances.B = {
+            module.name = "service-B";
+            module.input = "self";
+            roles.default.tags = [ "all" ];
+          };
+        };
+        # <- inventory
+        #
+        # -> exports
+        /**
+          Current state
+          {
+            instances = {
+              hello = { networking = null; };
+            };
+            machines = {
+              jon = { networking = null; };
+            };
+          }
+        */
+        /**
+          Target state: (Flat attribute set)
+
+          tdlr;
+
+          # roles / instance level definitions may not exist on their own
+          # role and instance names are completely arbitrary.
+          # For example what does it mean: this is a export for all "peer" roles of all service-instances? That would be magic on the roleName.
+          # Or exports for all instances with name "ifoo" ? That would be magic on the instanceName.
+
+          # Practical combinations
+          # always include either the service name or the machine name
+
+          exports = {
+            # Clan level (1)
+            "///" networks generators
+
+            # Service anchored (8) : min 1 instance is needed ; machines may not exist
+            "A///" <- service specific
+            "A/instance//" <- instance of a service
+            "A//peer/" <- role of a service
+            "A/instance/peer/" <- instance+role of a service
+            "A///machine" <- machine of a service
+            "A/instance//machine" <- machine + instance of a service
+            "A//role/machine" <- machine + role of a service
+            "A/instance/role/machine" <- machine + role + instance of a service
+
+            # Machine anchored (1 or 2)
+            "///jon" <- this machine
+            "A///jon" <- role on a machine (dupped with service anchored)
+
+            # Unpractical; probably not needed (5)
+            "//peer/jon" <- role on a machine
+            "/instance//jon" <- role on a machine
+            "/instance//" <- instance: All "foo" instances everywhere?
+            "//role/" <- role: All "peer" roles everywhere?
+            "/instance/role/" <- instance role: Applies to all services, whose instance name has "ifoo" and role is "peer" (double magic)
+
+            # TODO: lazyattrs poc
+          }
+        */
+      };
+    in
+    {
+      inherit eval;
+      expr = eval;
+      expected = 42;
+    };
+}

lib/types/default.nix

@@ -1,4 +1,21 @@
 { lib, ... }:
+let
+  inherit (lib)
+    mapAttrs
+    attrNames
+    showOption
+    setDefaultModuleLocation
+    mkOptionType
+    isAttrs
+    filterAttrs
+    intersectAttrs
+    mapAttrsToList
+    mkOptionDefault
+    zipAttrsWith
+    seq
+    fix
+    ;
+in
 {
   /**
     A custom type for deferred modules that guarantee to be JSON serializable.
@@ -12,7 +29,7 @@
     - Enforces that the definition is JSON serializable
     - Disallows nested imports
   */
-  uniqueDeferredSerializableModule = lib.fix (
+  uniqueDeferredSerializableModule = fix (
     self:
     let
       checkDef =
@@ -23,19 +40,18 @@
           def;
     in
     # Essentially the "raw" type, but with a custom name and check
-    lib.mkOptionType {
+    mkOptionType {
       name = "deferredModule";
       description = "deferred custom module. Must be JSON serializable.";
       descriptionClass = "noun";
       # Unfortunately, tryEval doesn't catch JSON errors
-      check = value: lib.seq (builtins.toJSON value) (lib.isAttrs value);
+      check = value: seq (builtins.toJSON value) (isAttrs value);
       merge = lib.options.mergeUniqueOption {
         message = "------";
         merge = loc: defs: {
           imports = map (
             def:
-            lib.seq (checkDef loc def) lib.setDefaultModuleLocation
+            seq (checkDef loc def) setDefaultModuleLocation "${def.file}, via option ${showOption loc}"
-              "${def.file}, via option ${lib.showOption loc}"
               def.value
           ) defs;
         };
@@ -48,4 +64,113 @@
       };
     }
   );
+
+  /**
+    New submodule type that allows merging at the attribute level.
+
+    :::note
+    'record' type adopted from https://github.com/NixOS/nixpkgs/pull/334680
+    :::
+
+    It applies additional constraints to immediate child options:
+
+    - No support for 'readOnly'
+    - No support for 'apply'
+    - No support for type-merging: That means the modules options must be pre-declared directly.
+  */
+  record =
+    {
+      optional ? { },
+      required ? { },
+      wildcardType ? null,
+    }:
+    mkOptionType {
+      name = "record";
+      description =
+        if wildcardType == null then "record" else "open record of ${wildcardType.description}";
+      descriptionClass = if wildcardType == null then "noun" else "composite";
+      check = isAttrs;
+      merge.v2 =
+        { loc, defs }:
+        let
+          pushPositions = map (
+            def:
+            mapAttrs (_n: v: {
+              inherit (def) file;
+              value = v;
+            }) def.value
+          );
+
+          # Checks
+          intersection = intersectAttrs optional required;
+          optionalDefault = filterAttrs (_: opt: opt ? default) optional;
+
+          # Definitions + option defaults
+          allDefs =
+            defs
+            ++ (mapAttrsToList (name: opt: {
+              file = (builtins.unsafeGetAttrPos name required).file or "<unknown-file>";
+              value = {
+                ${name} = mkOptionDefault opt.default;
+              };
+            }) (filterAttrs (_n: opt: opt ? default) required));
+
+          merged = zipAttrsWith (
+            name: defs:
+            let
+              elemType = optional.${name}.type or required.${name}.type or wildcardType;
+            in
+            lib.modules.mergeDefinitions (loc ++ [ name ]) elemType defs
+          ) (pushPositions allDefs);
+        in
+        {
+          headError =
+            if intersection != { } then
+              {
+                message = "The following attributes of '${showOption loc}' are both declared in 'optional' and in 'required': ${lib.concatStringsSep ", " (attrNames intersection)}";
+              }
+            else if optionalDefault != { } then
+              {
+                message = "The following attributes of '${showOption loc}' are declared in 'optional' cannot have a default value: ${lib.concatStringsSep ", " (attrNames optionalDefault)}";
+              }
+            else
+              null;
+          # TODO: expose fields, fieldValues and extraValues
+          valueMeta = {
+            attrs = mapAttrs (_n: v: v.checkedAndMerged.valueMeta) merged;
+          };
+          value = mapAttrs (
+            name: v:
+            let
+              elemType = optional.${name}.type or required.${name}.type or wildcardType;
+            in
+            if required ? ${name} then
+              # Non-optional, lazy ?
+              v.mergedValue
+            else
+              # Optional, lazy
+              v.optionalValue.value or elemType.emptyValue.value or v.mergedValue
+          ) merged;
+        };
+      nestedTypes = lib.optionalAttrs (wildcardType != null) {
+        inherit wildcardType;
+      };
+      getSubOptions =
+        prefix:
+        # Since this type doesn't support type merging, we can safely use the original attrs to display documentation.
+        mapAttrs (
+          name: opt:
+          (
+            opt
+            // {
+              loc = prefix ++ [ name ];
+              inherit name;
+              declarations = [
+                (builtins.unsafeGetAttrPos name optional).file or (builtins.unsafeGetAttrPos name required).file
+                  or "<unknown-file>"
+              ];
+            }
+          )
+        ) (optional // required);
+    };
 }

lib/types/record_tests.nix

@@ -0,0 +1,44 @@
+{ lib, clanLib, ... }:
+let
+  inherit (lib) evalModules mkOption;
+  inherit (clanLib.types) record;
+in
+{
+  test_simple =
+    let
+      eval = evalModules {
+        modules = [
+          {
+            options.foo = mkOption {
+              type = record { };
+              default = { };
+            };
+          }
+        ];
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expected = { };
+    };
+
+  test_wildcard =
+    let
+      eval = evalModules {
+        modules = [
+          {
+            options.foo = mkOption {
+              type = record { };
+              default = { };
+            };
+          }
+        ];
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expected = { };
+    };
+}

lib/types/tests.nix

@@ -1,92 +1,5 @@
 { lib, clanLib, ... }:
-let
-  evalSettingsModule =
-    m:
-    lib.evalModules {
-      modules = [
-        {
-          options.foo = lib.mkOption {
-            type = clanLib.types.uniqueDeferredSerializableModule;
-          };
-        }
-        m
-      ];
-    };
-in
 {
-  test_simple =
+  unique = import ./unique_tests.nix { inherit lib clanLib; };
-    let
+  record = import ./record_tests.nix { inherit lib clanLib; };
-      eval = evalSettingsModule {
-        foo = { };
-      };
-    in
-    {
-      inherit eval;
-      expr = eval.config.foo;
-      expected = {
-        # Foo has imports
-        # This can only ever be one module due to the type of foo
-        imports = [
-          {
-            # This is the result of 'setDefaultModuleLocation'
-            # Which also returns exactly one module
-            _file = "<unknown-file>, via option foo";
-            imports = [
-              { }
-            ];
-          }
-        ];
-      };
-    };
-
-  test_no_nested_imports =
-    let
-      eval = evalSettingsModule {
-        foo = {
-          imports = [ ];
-        };
-      };
-    in
-    {
-      inherit eval;
-      expr = eval.config.foo;
-      expectedError = {
-        type = "ThrownError";
-        message = "*nested imports";
-      };
-    };
-
-  test_no_function_modules =
-    let
-      eval = evalSettingsModule {
-        foo =
-          { ... }:
-          {
-
-          };
-      };
-    in
-    {
-      inherit eval;
-      expr = eval.config.foo;
-      expectedError = {
-        type = "TypeError";
-        message = "cannot convert a function to JSON";
-      };
-    };
-
-  test_non_attrs_module =
-    let
-      eval = evalSettingsModule {
-        foo = "foo.nix";
-      };
-    in
-    {
-      inherit eval;
-      expr = eval.config.foo;
-      expectedError = {
-        type = "ThrownError";
-        message = ".*foo.* is not of type";
-      };
-    };
 }

lib/types/unique_tests.nix

@@ -0,0 +1,92 @@
+{ lib, clanLib, ... }:
+let
+  evalSettingsModule =
+    m:
+    lib.evalModules {
+      modules = [
+        {
+          options.foo = lib.mkOption {
+            type = clanLib.types.uniqueDeferredSerializableModule;
+          };
+        }
+        m
+      ];
+    };
+in
+{
+  test_not_defined =
+    let
+      eval = evalSettingsModule {
+        foo = { };
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expected = {
+        # Foo has imports
+        # This can only ever be one module due to the type of foo
+        imports = [
+          {
+            # This is the result of 'setDefaultModuleLocation'
+            # Which also returns exactly one module
+            _file = "<unknown-file>, via option foo";
+            imports = [
+              { }
+            ];
+          }
+        ];
+      };
+    };
+
+  test_no_nested_imports =
+    let
+      eval = evalSettingsModule {
+        foo = {
+          imports = [ ];
+        };
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expectedError = {
+        type = "ThrownError";
+        message = "*nested imports";
+      };
+    };
+
+  test_no_function_modules =
+    let
+      eval = evalSettingsModule {
+        foo =
+          { ... }:
+          {
+
+          };
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expectedError = {
+        type = "TypeError";
+        message = "cannot convert a function to JSON";
+      };
+    };
+
+  test_non_attrs_module =
+    let
+      eval = evalSettingsModule {
+        foo = "foo.nix";
+      };
+    in
+    {
+      inherit eval;
+      expr = eval.config.foo;
+      expectedError = {
+        type = "ThrownError";
+        message = ".*foo.* is not of type";
+      };
+    };
+}

modules/clan/distributed-services.nix

@@ -111,11 +111,11 @@ in
       };
       modules = [
         (import ../../lib/inventory/distributed-service/all-services-wrapper.nix {
-          inherit (clanConfig) directory;
+          inherit (clanConfig) directory exports;
         })
         # Dependencies
         {
-          exportsModule = clanConfig.exportsModule;
+          # exportsModule = clanConfig.exportsModule;
         }
         {
           # TODO: Rename to "allServices"

modules/clan/top-level-interface.nix

@@ -110,9 +110,7 @@ in
 
     # TODO: make this writable by moving the options from inventoryClass into clan.
     exports = lib.mkOption {
-      readOnly = true;
+      type = types.lazyAttrsOf (types.submoduleWith { modules = [ config.exportsModule ]; });
-      visible = false;
-      internal = true;
     };
 
     exportsModule = lib.mkOption {