Implement loading rescheduler's policy config from versioned config.

pkg/rescheduler/policyconfig.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2017 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 rescheduler
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	//"k8s.io/apimachinery/pkg/runtime/serializer"
+	//kapi "k8s.io/kubernetes/pkg/api"
+
+	"github.com/aveshagarwal/rescheduler/pkg/api"
+	_ "github.com/aveshagarwal/rescheduler/pkg/api/install"
+	"github.com/aveshagarwal/rescheduler/pkg/api/v1alpha1"
+	"github.com/aveshagarwal/rescheduler/pkg/rescheduler/scheme"
+)
+
+func LoadPolicyConfig(policyConfigFile string) (*api.ReschedulerPolicy, error) {
+	if policyConfigFile == "" {
+		fmt.Printf("policy config file not specified")
+		return nil, nil
+	}
+
+	policy, err := ioutil.ReadFile(policyConfigFile)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read policy config file %q: %+v", policyConfigFile, err)
+	}
+
+	versionedPolicy := &v1alpha1.ReschedulerPolicy{}
+
+	//decoder := kapi.Codecs.UniversalDecoder(v1alpha1.SchemeGroupVersion)
+	decoder := scheme.Codecs.UniversalDecoder(v1alpha1.SchemeGroupVersion)
+	if err := runtime.DecodeInto(decoder, policy, versionedPolicy); err != nil {
+		return nil, fmt.Errorf("failed decoding rescheduler's policy config %q: %v", policyConfigFile, err)
+	}
+
+	//codecs := serializer.NewCodecFactory(scheme.Scheme)
+	//decoder := scheme.Codecs.UniversalDecoder()
+	/*decoder := kapi.Codecs.UniversalDecoder()
+	decodedObj, err := runtime.Decode(decoder, policy)
+	if err != nil {
+		return nil, err
+	}
+	internalPolicy, ok := decodedObj.(*api.ReschedulerPolicy)
+	if !ok {
+		return nil, fmt.Errorf("unexpected type: %T", decodedObj)
+	}*/
+
+	internalPolicy := &api.ReschedulerPolicy{}
+	//if err := kapi.Scheme.Convert(versionedPolicy, internalPolicy, nil); err != nil {
+	if err := scheme.Scheme.Convert(versionedPolicy, internalPolicy, nil); err != nil {
+		return nil, fmt.Errorf("failed converting versioned policy to internal policy version: %v", err)
+	}
+
+	return internalPolicy, nil
+}