remove the duplicate address of glusterfs

pkg/volume/glusterfs/BUILD

@@ -33,6 +33,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
         "//vendor/k8s.io/utils/exec:go_default_library",
     ],

pkg/volume/glusterfs/glusterfs.go

@@ -35,6 +35,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/sets"
 	clientset "k8s.io/client-go/kubernetes"
 	v1helper "k8s.io/kubernetes/pkg/api/v1/helper"
 	"k8s.io/kubernetes/pkg/util/mount"
@@ -322,14 +323,16 @@ func (b *glusterfsMounter) setUpAtInternal(dir string) error {
 	if b.hosts == nil {
 		return fmt.Errorf("glusterfs: endpoint is nil")
 	}
-	addr := make(map[string]struct{})
+	addr := sets.String{}
 	if b.hosts.Subsets != nil {
 		for _, s := range b.hosts.Subsets {
 			for _, a := range s.Addresses {
-				addr[a.IP] = struct{}{}
+				if !addr.Has(a.IP) {
+					addr.Insert(a.IP)
 					addrlist = append(addrlist, a.IP)
 				}
 			}
+		}
 
 	}
 	options = append(options, "backup-volfile-servers="+dstrings.Join(addrlist[:], ":"))