Add a helper function to decode scheduler plugin args

pkg/scheduler/framework/v1alpha1/BUILD

@@ -19,8 +19,10 @@ go_library(
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/json:go_default_library",
         "//staging/src/k8s.io/client-go/util/workqueue:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
+        "//vendor/sigs.k8s.io/yaml:go_default_library",
     ],
 )
 
@@ -43,10 +45,12 @@ go_test(
     srcs = [
         "framework_test.go",
         "interface_test.go",
+        "registry_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
         "//pkg/scheduler/apis/config:go_default_library",
+        "//pkg/scheduler/apis/config/scheme:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",

pkg/scheduler/framework/v1alpha1/registry.go

@@ -20,11 +20,30 @@ import (
 	"fmt"
 
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/json"
+	"sigs.k8s.io/yaml"
 )
 
 // PluginFactory is a function that builds a plugin.
 type PluginFactory = func(configuration *runtime.Unknown, f FrameworkHandle) (Plugin, error)
 
+// DecodeInto decodes configuration whose type is *runtime.Unknown to the interface into.
+func DecodeInto(configuration *runtime.Unknown, into interface{}) error {
+	if configuration == nil {
+		return nil
+	}
+
+	switch configuration.ContentType {
+	// If ContentType is empty, it means ContentTypeJSON by default.
+	case runtime.ContentTypeJSON, "":
+		return json.Unmarshal(configuration.Raw, into)
+	case runtime.ContentTypeYAML:
+		return yaml.Unmarshal(configuration.Raw, into)
+	default:
+		return fmt.Errorf("not supported content type %s", configuration.ContentType)
+	}
+}
+
 // Registry is a collection of all available plugins. The framework uses a
 // registry to enable and initialize configured plugins.
 // All plugins must be in the registry before initializing the framework.

pkg/scheduler/framework/v1alpha1/registry_test.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config/scheme"
+)
+
+func TestDecodeInto(t *testing.T) {
+	type PluginFooConfig struct {
+		FooTest string `json:"foo_test,omitempty"`
+	}
+	tests := []struct {
+		name            string
+		schedulerConfig string
+		expeted         PluginFooConfig
+	}{
+		{
+			name: "test decode for JSON config",
+			schedulerConfig: `{
+				"kind": "KubeSchedulerConfiguration",
+				"apiVersion": "kubescheduler.config.k8s.io/v1alpha1",
+				"plugins": {
+				"permit": {
+						"enabled": [
+							{
+								"name": "foo"
+							}
+						]
+					}
+				},
+				"pluginConfig": [
+					{
+						"name": "foo",
+						"args": {
+							"foo_test": "test decode"
+						}
+					}
+				]
+			}`,
+			expeted: PluginFooConfig{
+				FooTest: "test decode",
+			},
+		},
+		{
+			name: "test decode for YAML config",
+			schedulerConfig: `
+apiVersion: kubescheduler.config.k8s.io/v1alpha1
+kind: KubeSchedulerConfiguration
+plugins:
+  permit:
+    enabled:
+      - name: foo
+pluginConfig:
+  - name: foo
+    args:
+      foo_test: "test decode"`,
+			expeted: PluginFooConfig{
+				FooTest: "test decode",
+			},
+		},
+	}
+	for i, test := range tests {
+		schedulerConf, err := loadConfig([]byte(test.schedulerConfig))
+		if err != nil {
+			t.Errorf("Test #%v(%s): failed to load scheduler config: %v", i, test.name, err)
+		}
+		var pluginFooConf PluginFooConfig
+		if err := DecodeInto(&schedulerConf.PluginConfig[0].Args, &pluginFooConf); err != nil {
+			t.Errorf("Test #%v(%s): failed to decode args %+v: %v",
+				i, test.name, schedulerConf.PluginConfig[0].Args, err)
+		}
+		if !reflect.DeepEqual(pluginFooConf, test.expeted) {
+			t.Errorf("Test #%v(%s): failed to decode plugin config, expected: %+v, got: %+v",
+				i, test.name, test.expeted, pluginFooConf)
+		}
+	}
+}
+
+func loadConfig(data []byte) (*config.KubeSchedulerConfiguration, error) {
+	configObj := &config.KubeSchedulerConfiguration{}
+	if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), data, configObj); err != nil {
+		return nil, err
+	}
+
+	return configObj, nil
+}