diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go b/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go
new file mode 100644
index 0000000..901be9d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go
@@ -0,0 +1,38 @@
+// Copyright 2016 The etcd 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 api
+
+import (
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+// Cluster is an interface representing a collection of members in one etcd cluster.
+type Cluster interface {
+	// ID returns the cluster ID
+	ID() types.ID
+	// ClientURLs returns an aggregate set of all URLs on which this
+	// cluster is listening for client requests
+	ClientURLs() []string
+	// Members returns a slice of members sorted by their ID
+	Members() []*membership.Member
+	// Member retrieves a particular member based on ID, or nil if the
+	// member does not exist in the cluster
+	Member(id types.ID) *membership.Member
+	// Version is the cluster-wide minimum major.minor version.
+	Version() *semver.Version
+}