glusterfile-provisioner.go

/*
Copyright 2018 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 main

import (
	"flag"
	"fmt"
	"os"
	"strconv"
	dstrings "strings"

	gcli "github.com/heketi/heketi/client/api/go-client"
	gapi "github.com/heketi/heketi/pkg/glusterfs/api"
	"github.com/kubernetes-sigs/sig-storage-lib-external-provisioner/controller"
	"github.com/kubernetes-sigs/sig-storage-lib-external-provisioner/gidallocator"
	"github.com/kubernetes-sigs/sig-storage-lib-external-provisioner/util"
	"github.com/pborman/uuid"
	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/retry"
	"k8s.io/klog"
	"k8s.io/kubernetes/pkg/volume"
)

const (
	provisionerName           = "gluster.org/glusterfile"
	provisionerNameKey        = "PROVISIONER_NAME"
	descAnn                   = "Gluster-external: Dynamically provisioned PV"
	restStr                   = "server"
	dynamicEpSvcPrefix        = "glusterfile-dynamic-"
	replicaCount              = 3
	secretKeyName             = "key" // key name used in secret
	volPrefix                 = "vol_"
	mountStr                  = "auto_unmount"
	glusterTypeAnn            = "gluster.org/type"
	heketiVolIDAnn            = "gluster.org/heketi-volume-id"
	gidAnn                    = "pv.beta.kubernetes.io/gid"
	defaultThinPoolSnapFactor = float32(1.0) // thin pool snap factor default to 1.0

	// CloneRequestAnn is an annotation to request that the PVC be provisioned as a clone of the referenced PVC
	CloneRequestAnn = "k8s.io/CloneRequest"

	// CloneOfAnn is an annotation to indicate that a PVC is a clone of the referenced PVC
	CloneOfAnn = "k8s.io/CloneOf"
)

type glusterfileProvisioner struct {
	client   kubernetes.Interface
	identity string
	provisionerConfig
	allocator gidallocator.Allocator
	options   controller.VolumeOptions
}

type provisionerConfig struct {
	url                string
	user               string
	userKey            string
	secretNamespace    string
	secretName         string
	secretValue        string
	clusterID          string
	gidMin             int
	gidMax             int
	volumeType         gapi.VolumeDurabilityInfo
	volumeOptions      []string
	volumeNamePrefix   string
	thinPoolSnapFactor float32
}

//NewglusterfileProvisioner create a new provisioner.
func NewglusterfileProvisioner(client kubernetes.Interface, id string) controller.Provisioner {
	return &glusterfileProvisioner{
		client:    client,
		identity:  id,
		allocator: gidallocator.New(client),
	}
}

var _ controller.Provisioner = &glusterfileProvisioner{}

func (p *glusterfileProvisioner) GetAccessModes() []v1.PersistentVolumeAccessMode {
	return []v1.PersistentVolumeAccessMode{
		v1.ReadWriteMany,
		v1.ReadOnlyMany,
		v1.ReadWriteOnce,
	}
}

func (p *glusterfileProvisioner) getPVC(ns string, name string) (*v1.PersistentVolumeClaim, error) {
	return p.client.CoreV1().PersistentVolumeClaims(ns).Get(name, metav1.GetOptions{})
}

func (p *glusterfileProvisioner) annotatePVC(ns string, name string, updates map[string]string) error {
	retryErr := retry.RetryOnConflict(retry.DefaultRetry, func() error {
		// Retrieve the latest version of PVC before attempting update
		// RetryOnConflict uses exponential backoff to avoid exhausting the apiserver
		result, getErr := p.client.CoreV1().PersistentVolumeClaims(ns).Get(name, metav1.GetOptions{})
		if getErr != nil {
			panic(fmt.Errorf("Failed to get latest version of PVC: %v", getErr))
		}

		for k, v := range updates {
			result.Annotations[k] = v
		}
		_, updateErr := p.client.CoreV1().PersistentVolumeClaims(ns).Update(result)
		return updateErr
	})
	if retryErr != nil {
		return fmt.Errorf("Update failed: %v", retryErr)
	}
	return nil
}

// Provision creates a storage asset and returns a PV object representing it.
func (p *glusterfileProvisioner) Provision(options controller.VolumeOptions) (*v1.PersistentVolume, error) {

	sourceVolID := ""
	volID := ""
	var glusterfs *v1.GlusterfsVolumeSource

	smartclone := true
	if options.PVC.Spec.Selector != nil {
		return nil, fmt.Errorf("claim Selector is not supported")
	}

	if !util.AccessModesContainedInAll(p.GetAccessModes(), options.PVC.Spec.AccessModes) {
		return nil, fmt.Errorf("invalid AccessModes %v: only AccessModes %v are supported", options.PVC.Spec.AccessModes, p.GetAccessModes())
	}

	klog.V(1).Infof("VolumeOptions %v", options)
	p.options = options
	gidAllocate := true
	for k, v := range options.Parameters {
		switch dstrings.ToLower(k) {
		case "smartclone":
			smartclone = dstrings.ToLower(v) == "true"
		case "gidmin":
		// Let allocator handle
		case "gidmax":
		// Let allocator handle
		case "gidallocate":
			b, err := strconv.ParseBool(v)
			if err != nil {
				return nil, fmt.Errorf("invalid value %s for parameter %s: %v", v, k, err)
			}
			gidAllocate = b
		}
	}

	var gid *int
	if gidAllocate {
		allocate, err := p.allocator.AllocateNext(options)
		if err != nil {
			return nil, fmt.Errorf("allocator error: %v", err)
		}
		gid = &allocate

	}

	cfg, parseErr := p.parseClassParameters(options.Parameters, p.client)

	if parseErr != nil {
		return nil, fmt.Errorf("failed to parse storage class parameters: %v", parseErr)
	}

	klog.V(4).Infof("creating volume with configuration %+v", *cfg)

	modeAnn := "url:" + cfg.url + "," + "user:" + cfg.user + "," + "secret:" + cfg.secretName + "," + "secretnamespace:" + cfg.secretNamespace
	klog.V(1).Infof("Allocated GID %d for PVC %s", *gid, options.PVC.Name)

	gidStr := strconv.FormatInt(int64(*gid), 10)

	volSize := options.PVC.Spec.Resources.Requests[v1.ResourceName(v1.ResourceStorage)]
	volSizeBytes := volSize.Value()
	volszInt := int(util.RoundUpToGiB(volSizeBytes))

	if smartclone && (options.PVC.Annotations[CloneRequestAnn] != "") {
		if sourcePVCRef, ok := options.PVC.Annotations[CloneRequestAnn]; ok {
			var ns string
			parts := dstrings.SplitN(sourcePVCRef, "/", 2)
			if len(parts) < 2 {
				ns = options.PVC.Namespace
			} else {
				ns = parts[0]
			}
			sourcePVCName := parts[len(parts)-1]
			sourcePVC, err := p.getPVC(ns, sourcePVCName)
			if err != nil {
				return nil, fmt.Errorf("Unable to get PVC %s/%s", ns, sourcePVCName)
			}
			if sourceVolID, ok = sourcePVC.Annotations[heketiVolIDAnn]; ok {
				klog.Infof("Requesting clone of heketi volumeID %s", sourceVolID)
				cGlusterfs, sizeGiB, cVolID, createCloneErr := p.createVolumeClone(sourceVolID, cfg)
				if createCloneErr != nil {
					return nil, fmt.Errorf("failed to create clone of %v: %v", sourceVolID, createCloneErr)
				}
				if cGlusterfs != nil {
					glusterfs = cGlusterfs
				}
				volID = cVolID
				klog.Infof("glusterfs volume source %v with size %d retrieved", cGlusterfs, sizeGiB)
				err = p.annotateClonedPVC(cVolID, options.PVC, sourceVolID)
				if err != nil {
					return nil, fmt.Errorf("failed to annotate cloned PVC %s :%v", options.PVC, err)
					//todo: cleanup?
				}
			} else {
				return nil, fmt.Errorf("PVC %s/%s missing %s annotation",
					ns, sourcePVCName, heketiVolIDAnn)
			}
		}
	} else {
		nGlusterfs, sizeGiB, nVolID, createErr := p.CreateVolume(gid, cfg, volszInt)
		if createErr != nil {
			return nil, fmt.Errorf("failed to create volume: %v", createErr)
		}
		klog.Infof("glusterfs volume source %v with size %d retrieved", nGlusterfs, sizeGiB)
		if nGlusterfs != nil {
			glusterfs = nGlusterfs
		}
		volID = nVolID
		annotations := make(map[string]string, 2)
		annotations[heketiVolIDAnn] = nVolID
		annotateErr := p.annotatePVC(options.PVC.Namespace, options.PVC.Name, annotations)
		if annotateErr != nil {
			klog.Errorf("annotating PVC %v failed: %v", options.PVC.Name, annotateErr)

		}
		klog.V(1).Infof("successfully created Gluster File volume %+v with size %d and volID %s", glusterfs, sizeGiB, volID)
	}

	if glusterfs == nil {
		return nil, fmt.Errorf("retrieved glusterfs volume source is nil")
	}

	mode := v1.PersistentVolumeFilesystem
	pv := &v1.PersistentVolume{
		ObjectMeta: metav1.ObjectMeta{
			Name: options.PVName,
			Annotations: map[string]string{
				gidAnn:                   gidStr,
				glusterTypeAnn:           "file",
				"Description":            descAnn,
				heketiVolIDAnn:           volID,
				restStr:                  modeAnn,
				v1.MountOptionAnnotation: mountStr,
			},
		},
		Spec: v1.PersistentVolumeSpec{
			PersistentVolumeReclaimPolicy: options.PersistentVolumeReclaimPolicy,
			AccessModes:                   options.PVC.Spec.AccessModes,
			VolumeMode:                    &mode,
			Capacity: v1.ResourceList{
				v1.ResourceName(v1.ResourceStorage): options.PVC.Spec.Resources.Requests[v1.ResourceName(v1.ResourceStorage)],
			},
			PersistentVolumeSource: v1.PersistentVolumeSource{
				Glusterfs: glusterfs,
			},
		},
	}

	return pv, nil
}

func (p *glusterfileProvisioner) createVolumeClone(sourceVolID string, config *provisionerConfig) (r *v1.GlusterfsVolumeSource, size int, volID string, err error) {

	if config.url == "" {
		return nil, 0, "", fmt.Errorf("failed to create glusterfs REST client, REST URL is empty")
	}

	cli := gcli.NewClient(config.url, config.user, config.secretValue)
	if cli == nil {
		return nil, 0, "", fmt.Errorf("failed to create glusterfs REST client, REST server authentication failed")
	}
	cloneReq := &gapi.VolumeCloneRequest{}
	cloneVolInfo, cloneErr := cli.VolumeClone(sourceVolID, cloneReq)
	if cloneErr != nil {
		return nil, 0, "", fmt.Errorf("failed to clone of volume %v: %v", sourceVolID, cloneErr)
	}
	klog.V(1).Infof("volume with size %d and name %s created", cloneVolInfo.Size, cloneVolInfo.Name)

	volID = cloneVolInfo.Id

	volSource, volErr := p.createVolumeSource(cli, cloneVolInfo)
	if volErr != nil {
		return nil, 0, "", fmt.Errorf("error [%v] when creating volume source  for volume %s", err, cloneVolInfo.Name)
	}

	if volSource == nil {
		return nil, 0, "", fmt.Errorf("Returned gluster volume is nil")
	}

	return volSource, cloneVolInfo.Size, cloneVolInfo.Id, nil
}

func (p *glusterfileProvisioner) createVolumeSource(cli *gcli.Client, volInfo *gapi.VolumeInfoResponse) (*v1.GlusterfsVolumeSource, error) {
	dynamicHostIps, err := getClusterNodes(cli, volInfo.Cluster)
	if err != nil {
		return nil, fmt.Errorf("error [%v] when getting cluster nodes for volume %s", err, volInfo.Name)
	}

	epServiceName := dynamicEpSvcPrefix + p.options.PVC.Name
	epNamespace := p.options.PVC.Namespace
	endpoint, service, err := p.createEndpointService(epNamespace, epServiceName, dynamicHostIps, p.options.PVC.Name)
	if err != nil {
		deleteErr := cli.VolumeDelete(volInfo.Id)
		if deleteErr != nil {
			klog.Errorf("error when deleting the volume: %v, manual deletion required", deleteErr)
		}
		return nil, fmt.Errorf("failed to create endpoint/service %v/%v: %v", epNamespace, epServiceName, err)
	}
	klog.V(3).Infof("dynamic endpoint %v and service %v", endpoint, service)

	return &v1.GlusterfsVolumeSource{
		EndpointsName: endpoint.Name,
		Path:          volInfo.Name,
		ReadOnly:      false,
	}, nil
}

func (p *glusterfileProvisioner) annotateClonedPVC(VolID string, pvc *v1.PersistentVolumeClaim, SourceVolID string) error {
	annotations := make(map[string]string, 2)
	annotations[heketiVolIDAnn] = VolID

	// Add clone annotation if this is a cloned volume
	if sourcePVCName, ok := pvc.Annotations[CloneRequestAnn]; ok {
		if SourceVolID != "" {
			klog.Infof("Annotating PVC %s/%s as a clone of PVC %s/%s",
				pvc.Namespace, pvc.Name, pvc.Namespace, sourcePVCName)
			annotations[CloneOfAnn] = sourcePVCName
		}
	}
	err := p.annotatePVC(pvc.Namespace, pvc.Name, annotations)
	return err
}

func (p *glusterfileProvisioner) CreateVolume(gid *int, config *provisionerConfig, sz int) (r *v1.GlusterfsVolumeSource, size int, volID string, err error) {
	var clusterIDs []string
	customVolumeName := ""

	klog.V(2).Infof("create volume of size %dGiB and configuration %+v", sz, config)

	if config.url == "" {
		return nil, 0, "", fmt.Errorf("failed to create glusterfs REST client, REST URL is empty")
	}

	cli := gcli.NewClient(config.url, config.user, config.secretValue)
	if cli == nil {
		return nil, 0, "", fmt.Errorf("failed to create glusterfs REST client, REST server authentication failed")
	}

	if config.clusterID != "" {
		clusterIDs = dstrings.Split(config.clusterID, ",")
		klog.V(4).Infof("provided clusterIDs %v", clusterIDs)
	}

	if config.volumeNamePrefix != "" {
		customVolumeName = fmt.Sprintf("%s_%s_%s_%s", config.volumeNamePrefix, p.options.PVC.Namespace, p.options.PVC.Name, uuid.NewUUID())
	}

	gid64 := int64(*gid)

	snaps := struct {
		Enable bool    `json:"enable"`
		Factor float32 `json:"factor"`
	}{
		true,
		config.thinPoolSnapFactor,
	}

	volumeReq := &gapi.VolumeCreateRequest{Size: sz, Name: customVolumeName, Clusters: clusterIDs, Gid: gid64, Durability: p.volumeType, GlusterVolumeOptions: p.volumeOptions, Snapshot: snaps}

	volume, err := cli.VolumeCreate(volumeReq)
	if err != nil {
		return nil, 0, "", fmt.Errorf("failed to create gluster volume: %v", err)
	}

	klog.V(1).Infof("volume with size %d and name %s created", volume.Size, volume.Name)

	volID = volume.Id

	volSource, volErr := p.createVolumeSource(cli, volume)
	if volErr != nil {
		return nil, 0, "", fmt.Errorf("error [%v] when creating volume source  for volume %s", err, volume.Name)
	}

	if volSource == nil {
		return nil, 0, "", fmt.Errorf("Returned gluster volume is nil")
	}

	return volSource, sz, volID, nil
}

func (p *glusterfileProvisioner) RequiresFSResize() bool {
	return false
}

func (p *glusterfileProvisioner) ExpandVolumeDevice(spec *volume.Spec, newSize resource.Quantity, oldSize resource.Quantity) (resource.Quantity, error) {
	pvSpec := spec.PersistentVolume.Spec
	volumeName := pvSpec.Glusterfs.Path
	klog.V(2).Infof("Request to expand volume: [%s]", volumeName)
	volumeID, err := getVolumeID(spec.PersistentVolume, volumeName)

	if err != nil {
		return oldSize, fmt.Errorf("failed to get volumeID for volume [%s], err: %v", volumeName, err)
	}

	heketiModeArgs, credErr := p.getRESTCredentials(spec.PersistentVolume)
	if credErr != nil {
		return oldSize, fmt.Errorf("failed to retrieve REST credentials from pv: %v", credErr)
	}

	klog.V(4).Infof("Expanding volume %q with configuration %+v", volumeID, heketiModeArgs)

	//Create REST server connection
	cli := gcli.NewClient(heketiModeArgs["url"], heketiModeArgs["user"], heketiModeArgs["restsecretvalue"])
	if cli == nil {
		return oldSize, fmt.Errorf("failed to create glusterfs REST client, REST server authentication failed")
	}

	// Find out delta size
	expansionSize := (newSize.Value() - oldSize.Value())

	expansionSizeGiB := int(util.RoundUpToGiB(expansionSize))

	// Find out requested Size
	requestGiB := int(util.RoundUpToGiB(newSize.Value()))

	//Check the existing volume size
	currentVolumeInfo, err := cli.VolumeInfo(volumeID)
	if err != nil {
		return oldSize, fmt.Errorf("error when fetching details of volume[%s]: %v", volumeName, err)

	}

	if (currentVolumeInfo.Size) >= requestGiB {
		return newSize, nil
	}

	// Make volume expansion request
	volumeExpandReq := &gapi.VolumeExpandRequest{Size: expansionSizeGiB}

	// Expand the volume
	volumeInfoRes, err := cli.VolumeExpand(volumeID, volumeExpandReq)
	if err != nil {
		return oldSize, fmt.Errorf("error when expanding the volume[%s]: %v", volumeName, err)
	}

	klog.V(2).Infof("volume %s expanded to new size %d successfully", volumeName, volumeInfoRes.Size)
	newVolumeSize := resource.MustParse(fmt.Sprintf("%dGi", volumeInfoRes.Size))
	return newVolumeSize, nil
}

func (p *glusterfileProvisioner) createEndpointService(namespace string, epServiceName string, hostips []string, pvcname string) (endpoint *v1.Endpoints, service *v1.Service, err error) {

	addrlist := make([]v1.EndpointAddress, len(hostips))
	for i, v := range hostips {
		addrlist[i].IP = v
	}
	endpoint = &v1.Endpoints{
		ObjectMeta: metav1.ObjectMeta{
			Namespace: namespace,
			Name:      epServiceName,
			Labels: map[string]string{
				"gluster.org/provisioned-for-pvc": pvcname,
			},
		},
		Subsets: []v1.EndpointSubset{{
			Addresses: addrlist,
			Ports:     []v1.EndpointPort{{Port: 1, Protocol: "TCP"}},
		}},
	}
	kubeClient := p.client
	if kubeClient == nil {
		return nil, nil, fmt.Errorf("failed to get kube client when creating endpoint service")
	}
	_, err = kubeClient.CoreV1().Endpoints(namespace).Create(endpoint)
	if err != nil && errors.IsAlreadyExists(err) {
		klog.V(1).Infof("endpoint %s already exist in namespace %s", endpoint, namespace)
		err = nil
	}
	if err != nil {
		return nil, nil, fmt.Errorf("failed to create endpoint: %v", err)
	}

	service = &v1.Service{
		ObjectMeta: metav1.ObjectMeta{
			Name:      epServiceName,
			Namespace: namespace,
			Labels: map[string]string{
				"gluster.org/provisioned-for-pvc": pvcname,
			},
		},
		Spec: v1.ServiceSpec{
			Ports: []v1.ServicePort{
				{Protocol: "TCP", Port: 1}}}}
	_, err = kubeClient.CoreV1().Services(namespace).Create(service)
	if err != nil && errors.IsAlreadyExists(err) {
		klog.V(1).Infof("service %s already exist in namespace %s", service, namespace)
		err = nil
	}
	if err != nil {
		return nil, nil, fmt.Errorf("error creating service: %v", err)
	}
	return endpoint, service, nil
}

func getClusterNodes(cli *gcli.Client, cluster string) (dynamicHostIps []string, err error) {
	clusterinfo, err := cli.ClusterInfo(cluster)
	if err != nil {
		return nil, fmt.Errorf("failed to get cluster details: %v", err)
	}

	// For the dynamically provisioned volume, we gather the list of node IPs
	// of the cluster on which provisioned volume belongs to, as there can be multiple
	// clusters.
	for _, node := range clusterinfo.Nodes {
		nodei, err2 := cli.NodeInfo(string(node))
		if err2 != nil {
			return nil, fmt.Errorf("failed to get host ipaddress: %v", err2)
		}
		ipaddr := dstrings.Join(nodei.NodeAddRequest.Hostnames.Storage, "")
		dynamicHostIps = append(dynamicHostIps, ipaddr)
	}
	klog.V(3).Infof("host list :%v", dynamicHostIps)
	if len(dynamicHostIps) == 0 {
		return nil, fmt.Errorf("no hosts found: %v", err)
	}
	return dynamicHostIps, nil
}

// getVolumeID returns volumeID from the PV or volumename.
func getVolumeID(pv *v1.PersistentVolume, volumeName string) (string, error) {
	volumeID := ""

	// Get volID from pvspec if available, else fill it from volumename.
	if pv != nil {
		if pv.Annotations[heketiVolIDAnn] != "" {
			volumeID = pv.Annotations[heketiVolIDAnn]
		} else {
			volumeID = dstrings.TrimPrefix(volumeName, volPrefix)
		}
	} else {
		return volumeID, fmt.Errorf("provided PV spec is nil")
	}
	if volumeID == "" {
		return volumeID, fmt.Errorf("volume ID is empty")
	}
	return volumeID, nil
}

func (p *glusterfileProvisioner) getRESTCredentials(pv *v1.PersistentVolume) (map[string]string, error) {
	restString, ok := pv.Annotations[restStr]
	if !ok {
		return nil, fmt.Errorf("volume annotation for server details not found on PV")
	}

	restStrSlice := dstrings.Split(restString, ",")
	heketiModeArgs := make(map[string]string)

	for _, v := range restStrSlice {
		if v != "" {
			s := dstrings.Split(v, ":")

			if s[0] == "url" {
				heketiModeArgs[s[0]] = dstrings.Join(s[1:], ":")
			} else {
				heketiModeArgs[s[0]] = s[1]
			}

		}
	}
	heketiModeArgs["restsecretvalue"] = ""
	if heketiModeArgs["secret"] != "" && heketiModeArgs["secretnamespace"] != "" {
		var err error
		heketiModeArgs["restsecretvalue"], err = parseSecret(heketiModeArgs["secretnamespace"], heketiModeArgs["secret"], p.client)
		if err != nil {
			return nil, fmt.Errorf("failed to parse secret %s: %v", heketiModeArgs["secret"], err)
		}
	}

	return heketiModeArgs, nil
}

func (p *glusterfileProvisioner) Delete(volume *v1.PersistentVolume) error {

	klog.V(1).Infof("deleting volume, path %s", volume.Spec.Glusterfs.Path)

	err := p.allocator.Release(volume)
	if err != nil {
		return err
	}

	volumeName := volume.Spec.Glusterfs.Path
	volumeID, err := getVolumeID(volume, volumeName)
	if err != nil {
		return fmt.Errorf("failed to get volumeID: %v", err)
	}

	heketiModeArgs, credErr := p.getRESTCredentials(volume)
	if credErr != nil {
		return fmt.Errorf("failed to retrieve REST credentials from pv: %v", credErr)
	}

	cli := gcli.NewClient(heketiModeArgs["url"], heketiModeArgs["user"], heketiModeArgs["restsecretvalue"])
	if cli == nil {
		return fmt.Errorf("failed to create REST client, REST server authentication failed")
	}

	deleteErr := cli.VolumeDelete(volumeID)
	if deleteErr != nil {
		return fmt.Errorf("error when deleting the volume:%v", deleteErr)
	}
	klog.V(2).Infof("volume %s deleted successfully", volumeName)

	//Deleter takes endpoint and endpointnamespace from pv spec.
	pvSpec := volume.Spec
	var dynamicEndpoint, dynamicNamespace string
	if pvSpec.ClaimRef == nil {
		return fmt.Errorf("ClaimRef is nil")
	}
	if pvSpec.ClaimRef.Namespace == "" {
		return fmt.Errorf("namespace is nil")
	}
	dynamicNamespace = pvSpec.ClaimRef.Namespace
	if pvSpec.Glusterfs.EndpointsName != "" {
		dynamicEndpoint = pvSpec.Glusterfs.EndpointsName
	}
	klog.V(3).Infof("dynamic namespace and endpoint : %v/%v", dynamicNamespace, dynamicEndpoint)
	err = p.deleteEndpointService(dynamicNamespace, dynamicEndpoint)
	if err != nil {
		klog.Errorf("error when deleting endpoint/service: %v", err)
	} else {
		klog.V(1).Infof("endpoint: %v/%v is deleted successfully", dynamicNamespace, dynamicEndpoint)
	}
	return nil

}

func (p *glusterfileProvisioner) deleteEndpointService(namespace string, epServiceName string) (err error) {
	kubeClient := p.client
	if kubeClient == nil {
		return fmt.Errorf("failed to get kube client when deleting endpoint service")
	}
	err = kubeClient.CoreV1().Services(namespace).Delete(epServiceName, nil)
	if err != nil {
		return fmt.Errorf("error deleting service %s/%s: %v", namespace, epServiceName, err)
	}
	klog.V(1).Infof("service/endpoint %s/%s deleted successfully", namespace, epServiceName)
	return nil
}

// parseSecret finds a given Secret instance and reads user password from it.
func parseSecret(namespace, secretName string, kubeClient kubernetes.Interface) (string, error) {

	secretMap, err := GetSecretForPV(namespace, secretName, provisionerName, kubeClient)
	if err != nil {
		return "", fmt.Errorf("failed to get secret %s/%s: %v", namespace, secretName, err)
	}
	if len(secretMap) == 0 {
		return "", fmt.Errorf("empty secret map")
	}
	secret := ""
	for k, v := range secretMap {
		if k == secretKeyName {
			return v, nil
		}
		secret = v
	}
	// If not found, the last secret in the map wins as done before
	return secret, nil
}

// GetSecretForPV locates secret by name and namespace, verifies the secret type, and returns secret map
func GetSecretForPV(restSecretNamespace, restSecretName, volumePluginName string, kubeClient kubernetes.Interface) (map[string]string, error) {
	secret := make(map[string]string)
	if kubeClient == nil {
		return secret, fmt.Errorf("Cannot get kube client")
	}
	secrets, err := kubeClient.Core().Secrets(restSecretNamespace).Get(restSecretName, metav1.GetOptions{})
	if err != nil {
		return secret, err
	}
	if secrets.Type != v1.SecretType(volumePluginName) {
		return secret, fmt.Errorf("cannot get secret of type %s", volumePluginName)
	}
	for name, data := range secrets.Data {
		secret[name] = string(data)
	}
	return secret, nil
}

func convertVolumeParam(volumeString string) (int, error) {

	count, err := strconv.Atoi(volumeString)
	if err != nil {
		return 0, fmt.Errorf("failed to parse %q", volumeString)
	}

	if count < 0 {
		return 0, fmt.Errorf("negative values are not allowed")
	}
	return count, nil
}

// parseClassParameters parses StorageClass.Parameters
func (p *glusterfileProvisioner) parseClassParameters(params map[string]string, kubeclient kubernetes.Interface) (*provisionerConfig, error) {
	var cfg provisionerConfig
	var err error

	authEnabled := true
	parseVolumeType := ""
	parseVolumeOptions := ""
	parseVolumeNamePrefix := ""
	parseThinPoolSnapFactor := ""

	cfg.thinPoolSnapFactor = defaultThinPoolSnapFactor

	for k, v := range params {
		switch dstrings.ToLower(k) {
		case "resturl":
			cfg.url = v
		case "restuser":
			cfg.user = v
		case "restuserkey":
			cfg.userKey = v
		case "restsecretname":
			cfg.secretName = v
		case "restsecretnamespace":
			cfg.secretNamespace = v
		case "clusterid":
			if len(v) != 0 {
				cfg.clusterID = v
			}
		case "restauthenabled":
			authEnabled = dstrings.ToLower(v) == "true"

		case "volumetype":
			parseVolumeType = v

		case "volumeoptions":
			if len(v) != 0 {
				parseVolumeOptions = v
			}
		case "volumenameprefix":
			if len(v) != 0 {
				parseVolumeNamePrefix = v
			}
		case "snapfactor":
			if len(v) != 0 {
				parseThinPoolSnapFactor = v
			}
		case "gidmin":
		case "gidmax":
		case "smartclone":
		default:
			return nil, fmt.Errorf("invalid option %q for volume plugin %s", k, provisionerName)
		}
	}

	if len(cfg.url) == 0 {
		return nil, fmt.Errorf("StorageClass for provisioner %s must contain 'resturl' parameter", provisionerName)
	}

	if len(parseVolumeType) == 0 {
		cfg.volumeType = gapi.VolumeDurabilityInfo{Type: gapi.DurabilityReplicate, Replicate: gapi.ReplicaDurability{Replica: replicaCount}}
	} else {
		parseVolumeTypeInfo := dstrings.Split(parseVolumeType, ":")

		switch parseVolumeTypeInfo[0] {
		case "replicate":
			if len(parseVolumeTypeInfo) >= 2 {
				newReplicaCount, convertErr := convertVolumeParam(parseVolumeTypeInfo[1])
				if convertErr != nil {
					return nil, fmt.Errorf("error %v when parsing value %q of option %s for volume plugin %s", convertErr, parseVolumeTypeInfo[1], "volumetype", provisionerName)
				}
				cfg.volumeType = gapi.VolumeDurabilityInfo{Type: gapi.DurabilityReplicate, Replicate: gapi.ReplicaDurability{Replica: newReplicaCount}}
			} else {
				cfg.volumeType = gapi.VolumeDurabilityInfo{Type: gapi.DurabilityReplicate, Replicate: gapi.ReplicaDurability{Replica: replicaCount}}
			}
		case "disperse":
			if len(parseVolumeTypeInfo) >= 3 {
				newDisperseData, convertErr := convertVolumeParam(parseVolumeTypeInfo[1])
				if err != nil {
					return nil, fmt.Errorf("error %v when parsing value %q of option %s for volume plugin %s", parseVolumeTypeInfo[1], convertErr, "volumetype", provisionerName)
				}
				newDisperseRedundancy, convertErr := convertVolumeParam(parseVolumeTypeInfo[2])
				if err != nil {
					return nil, fmt.Errorf("error %v when parsing value %q of option %s for volume plugin %s", convertErr, parseVolumeTypeInfo[2], "volumetype", provisionerName)
				}
				cfg.volumeType = gapi.VolumeDurabilityInfo{Type: gapi.DurabilityEC, Disperse: gapi.DisperseDurability{Data: newDisperseData, Redundancy: newDisperseRedundancy}}
			} else {
				return nil, fmt.Errorf("StorageClass for provisioner %q must have data:redundancy count set for disperse volumes in storage class option '%s'", provisionerName, "volumetype")
			}
		case "none":
			cfg.volumeType = gapi.VolumeDurabilityInfo{Type: gapi.DurabilityDistributeOnly}
		default:
			return nil, fmt.Errorf("error parsing value for option 'volumetype' for volume plugin %s", provisionerName)
		}
	}
	if !authEnabled {
		cfg.user = ""
		cfg.secretName = ""
		cfg.secretNamespace = ""
		cfg.userKey = ""
		cfg.secretValue = ""
	}

	if len(cfg.secretName) != 0 || len(cfg.secretNamespace) != 0 {
		// secretName + Namespace has precedence over userKey
		if len(cfg.secretName) != 0 && len(cfg.secretNamespace) != 0 {

			cfg.secretValue, err = parseSecret(cfg.secretNamespace, cfg.secretName, p.client)
			if err != nil {
				return nil, err
			}
		} else {
			return nil, fmt.Errorf("StorageClass for provisioner %q must have secretNamespace and secretName either both set or both empty", provisionerName)
		}
	} else {
		cfg.secretValue = cfg.userKey
	}

	if len(parseVolumeOptions) != 0 {
		volOptions := dstrings.Split(parseVolumeOptions, ",")
		if len(volOptions) == 0 {
			return nil, fmt.Errorf("StorageClass for provisioner %q must have valid (for e.g.,'client.ssl on') volume option", provisionerName)
		}
		cfg.volumeOptions = volOptions

	}

	if len(parseVolumeNamePrefix) != 0 {
		if dstrings.Contains(parseVolumeNamePrefix, "_") {
			return nil, fmt.Errorf("Storageclass parameter 'volumenameprefix' should not contain '_' in its value")
		}
		cfg.volumeNamePrefix = parseVolumeNamePrefix
	}

	if len(parseThinPoolSnapFactor) != 0 {
		thinPoolSnapFactor, err := strconv.ParseFloat(parseThinPoolSnapFactor, 32)
		if err != nil {
			return nil, fmt.Errorf("failed to convert snapfactor value %v to float32: %v", parseThinPoolSnapFactor, err)
		}
		if thinPoolSnapFactor < 1.0 || thinPoolSnapFactor > 100.0 {
			return nil, fmt.Errorf("invalid snapshot factor %v, the value of snapfactor must be between 1 to 100", thinPoolSnapFactor)
		}
		cfg.thinPoolSnapFactor = float32(thinPoolSnapFactor)
	}
	return &cfg, nil
}

var (
	master     = flag.String("master", "", "Master URL")
	kubeconfig = flag.String("kubeconfig", "", "Absolute path to the kubeconfig")
	id         = flag.String("id", "", "Unique provisioner identity")
)

func main() {
	klog.InitFlags(nil)
	flag.Parse()
	flag.Set("logtostderr", "true")

	// Create an InClusterConfig and use it to create a client for the controller
	// to use to communicate with Kubernetes

	var config *rest.Config
	var err error
	if *master != "" || *kubeconfig != "" {
		config, err = clientcmd.BuildConfigFromFlags(*master, *kubeconfig)
	} else {
		config, err = rest.InClusterConfig()
	}

	if err != nil {
		klog.Fatalf("Failed to create config: %v", err)
	}

	provName := provisionerName
	provEnvName := os.Getenv(provisionerNameKey)

	// Precedence is given for ProvisionerNameKey
	if provEnvName != "" && *id != "" {
		provName = provEnvName
	}

	if provEnvName == "" && *id != "" {
		provName = *id
	}

	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		klog.Fatalf("Failed to create client:%v", err)
	}

	// The controller needs to know what the server version is because out-of-tree
	// provisioners aren't officially supported until 1.5
	serverVersion, err := clientset.Discovery().ServerVersion()
	if err != nil {
		klog.Fatalf("Error getting server version:%v", err)
	}

	// Create the provisioner: it implements the Provisioner interface expected by
	// the controller
	glusterfileProvisioner := NewglusterfileProvisioner(clientset, provName)

	// Start the provision controller which will dynamically provision glusterfs
	// PVs

	pc := controller.NewProvisionController(
		clientset,
		provName,
		glusterfileProvisioner,
		serverVersion.GitVersion,
	)

	pc.Run(wait.NeverStop)
}