From 8536b0315183beff4175d1fdf26e4f38f70304ec Mon Sep 17 00:00:00 2001
From: Jaka Hudoklin <jaka@gatehub.net>
Date: Tue, 26 Feb 2019 21:23:14 +0100
Subject: [PATCH] feat(submodules): refactor defaults

---
 k8s/submodule.nix             |  35 +++++++-----
 submodules.nix                |  71 ++++++++++++++++-------
 tests/default.nix             |   1 +
 tests/submodules/defaults.nix | 102 ++++++++++++++++++++++++++++++++++
 4 files changed, 175 insertions(+), 34 deletions(-)
 create mode 100644 tests/submodules/defaults.nix

diff --git a/k8s/submodule.nix b/k8s/submodule.nix
index 143682f..fe9fc58 100644
--- a/k8s/submodule.nix
+++ b/k8s/submodule.nix
@@ -9,7 +9,7 @@ in {
 
   options = {
     kubernetes.propagateDefaults = mkOption {
-      description = "Whehter to propagate child defaults to submodules";
+      description = "Whether to propagate child defaults to submodules";
       type = types.bool;
       default = true;
     };
@@ -25,25 +25,32 @@ in {
         };
 
         config.config = {
-          kubernetes.api.defaults.all.metadata.namespace =
-            mkDefault config.namespace;
+          kubernetes.api.defaults = [{
+            default.metadata.namespace = mkDefault config.namespace;
+          }];
         };
       }));
     };
   };
 
   config = {
-    submodules.defaults = mkMerge [{
-      imports = [ kubenix.k8s ];
-      kubernetes.version = mkDefault config.kubernetes.version;
-      kubernetes.api.defaults =
-        mkIf config.kubernetes.propagateDefaults config.kubernetes.api.defaults;
-      } ({config, ...}: {
-        kubernetes.api.defaults.all.metadata.labels = {
-          "kubenix/module-name" = config.submodule.name;
-          "kubenix/module-version" = config.submodule.version;
-        };
-      })];
+    submodules.defaults = [{
+      default = {
+        imports = [ kubenix.k8s ];
+        kubernetes.version = mkDefault config.kubernetes.version;
+        kubernetes.api.defaults =
+          mkIf config.kubernetes.propagateDefaults config.kubernetes.api.defaults;
+      };
+    } {
+      default = ({config, ...}: {
+        kubernetes.api.defaults = [{
+          default.metadata.labels = {
+            "kubenix/module-name" = config.submodule.name;
+            "kubenix/module-version" = config.submodule.version;
+          };
+        }];
+      });
+    }];
 
     kubernetes.objects = mkMerge (mapAttrsToList (_: submodule:
       submodule.config.kubernetes.objects
diff --git a/submodules.nix b/submodules.nix
index 8d910d0..46a3025 100644
--- a/submodules.nix
+++ b/submodules.nix
@@ -5,6 +5,15 @@ with lib;
 let
   cfg = config.submodules;
 
+  getDefaults = name: tags:
+    catAttrs "default" (filter (submodule:
+      (submodule.name == null || submodule.name == name) &&
+      (
+        (length submodule.tags == 0) ||
+        (length (intersectLists submodule.tags tags)) > 0
+      )
+    ) config.submodules.defaults);
+
   submoduleWithSpecialArgs = opts: specialArgs:
     let
       opts' = toList opts;
@@ -69,9 +78,9 @@ let
         default = "1.0.0";
       };
 
-      passthru = mkOption {
-        description = "Submodule passthru";
-        type = types.coercedTo types.attrs (value: [value]) (types.listOf types.attrs);
+      tags = mkOption {
+        description = "List of submodule tags";
+        type = types.listOf types.str;
         default = [];
       };
     };
@@ -114,24 +123,35 @@ in {
     };
 
     submodules.defaults = mkOption {
-      description = "Submodule defaults";
-      type = types.coercedTo types.unspecified (value: [value]) (types.listOf types.unspecified);
-      example = literalExample ''{config, ...}: {
-        kubernetes.version = config.kubernetes.version;
-      }'';
-      default = [];
-    };
+      description = "List of defaults to apply to submodule instances";
+      type = types.listOf (types.submodule ({config, ...}: {
+        options = {
+          name = mkOption {
+            description = "Name of the submodule to apply defaults to";
+            type = types.nullOr types.str;
+            default = null;
+          };
 
-    submodules.propagateDefaults = mkOption {
-      description = "Whether to propagate defaults to submodules";
-      type = types.bool;
-      default = true;
+          tags = mkOption {
+            description = "List of tags to apply defaults to";
+            type = types.listOf types.str;
+            default = [];
+          };
+
+          default = mkOption {
+            description = "Default to apply to submodule instance";
+            type = types.unspecified;
+            default = {};
+          };
+        };
+      }));
+      default = [];
     };
 
     submodules.propagate = mkOption {
       description = "Whether to propagate defaults and imports to submodule's submodules";
       type = types.bool;
-      default = true;
+      default = false;
     };
 
     submodules.imports = mkOption {
@@ -150,6 +170,7 @@ in {
             options = {
               module = mkOption {
                 description = "Module defining submodule";
+                type = types.unspecified;
               };
 
               modules = mkOption {
@@ -172,12 +193,17 @@ in {
     submodules.instances = mkOption {
       description = "Attribute set of submodule instances";
       type = types.attrsOf (types.submodule ({name, config, ...}: let
+        # submodule associated with
         submodule = findModule {
           name = config.submodule;
           version = config.version;
         };
 
+        # definition of a submodule
         submoduleDefinition = submodule.definition;
+
+        # submodule defaults
+        defaults = getDefaults submoduleDefinition.name submoduleDefinition.tags;
       in {
         options = {
           name = mkOption {
@@ -201,7 +227,7 @@ in {
           config = mkOption {
             description = "Submodule instance ${config.name} for ${submoduleDefinition.name}:${submoduleDefinition.version} config";
             type = submoduleWithSpecialArgs ({...}: {
-              imports = submodule.modules ++ cfg.defaults ++ [submoduleOptions ./submodules.nix];
+              imports = submodule.modules ++ defaults ++ [submoduleOptions];
               _module.args.name = config.name;
             }) specialArgs;
             default = {};
@@ -214,9 +240,14 @@ in {
 
   config = {
     submodules.specialArgs.kubenix = kubenix;
-    submodules.defaults = mkIf cfg.propagate {
-      submodules.defaults = cfg.defaults;
-      submodules.imports = cfg.imports;
-    };
+    submodules.defaults = [(mkIf cfg.propagate {
+      default = {
+        imports = [./submodules.nix];
+        submodules = {
+          defaults = cfg.defaults;
+          imports = cfg.imports;
+        };
+      };
+    })];
   };
 }
diff --git a/tests/default.nix b/tests/default.nix
index c04577d..e3489c3 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -32,6 +32,7 @@ let
           ./k8s/1.13/crd.nix
           ./k8s/submodule.nix
           ./submodules/simple.nix
+          ./submodules/defaults.nix
         ];
         testing.defaults = ({kubenix, ...}: {
           imports = [kubenix.k8s];
diff --git a/tests/submodules/defaults.nix b/tests/submodules/defaults.nix
new file mode 100644
index 0000000..cd349bb
--- /dev/null
+++ b/tests/submodules/defaults.nix
@@ -0,0 +1,102 @@
+{ name, config, lib, kubenix, ... }:
+
+with lib;
+
+let
+  instance1 = config.submodules.instances.instance1;
+  instance2 = config.submodules.instances.instance2;
+  instance3 = config.submodules.instances.instance3;
+  instance4 = config.submodules.instances.instance4;
+
+  module = {name, ...}: {
+    options.args.value = mkOption {
+      description = "Submodule value";
+      type = types.str;
+    };
+
+    options.args.defaultValue = mkOption {
+      description = "Submodule default value";
+      type = types.str;
+    };
+  };
+in {
+  imports = [
+    kubenix.submodules
+  ];
+
+  test = {
+    name = "submodules-defatuls";
+    description = "Simple k8s submodule test";
+    assertions = [{
+      message = "instance1 should have value of value1";
+      assertion = instance1.config.args.value == "value1";
+    } {
+      message = "instance2 should have value of value2";
+      assertion = instance2.config.args.value == "value2";
+    } {
+      message = "instance2 should have value of value2";
+      assertion = instance3.config.args.value == "value2";
+    } {
+      message = "instance1 and instance2 should have value of value";
+      assertion =
+        instance1.config.args.defaultValue == "value" &&
+        instance2.config.args.defaultValue == "value";
+    } {
+      message = "instance1 and instance3 should have value of default-value";
+      assertion = instance3.config.args.defaultValue == "default-value";
+    } {
+      message = "instance4 should have value of value4";
+      assertion = instance4.config.args.value == "value4";
+    }];
+  };
+
+  submodules.imports = [{
+    modules = [module {
+      submodule = {
+        name = "submodule1";
+        tags = ["tag1"];
+      };
+    }];
+  } {
+    modules = [module {
+      submodule = {
+        name = "submodule2";
+        tags = ["tag2"];
+      };
+    }];
+  } {
+    modules = [module {
+      submodule = {
+        name = "submodule3";
+        tags = ["tag2"];
+      };
+    }];
+  } {
+    modules = [module {
+      submodule = {
+        name = "submodule4";
+      };
+    }];
+  }];
+
+  submodules.defaults = [{
+    default.args.defaultValue = mkDefault "value";
+  } {
+    tags = ["tag1"];
+    default.args.value = mkDefault "value1";
+  } {
+    tags = ["tag2"];
+    default.args.value = mkDefault "value2";
+  } {
+    name = "submodule4";
+    default.args.value = mkDefault "value4";
+  }];
+
+  submodules.instances.instance1.submodule = "submodule1";
+  submodules.instances.instance2.submodule = "submodule2";
+  submodules.instances.instance3 = {
+    submodule = "submodule3";
+    config.args.defaultValue = "default-value";
+  };
+  submodules.instances.instance4.submodule = "submodule4";
+}