diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go
new file mode 100644
index 0000000..8f6fe50
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go
@@ -0,0 +1,35 @@
+// 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 membership
+
+import (
+	"errors"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+)
+
+var (
+	ErrIDRemoved        = errors.New("membership: ID removed")
+	ErrIDExists         = errors.New("membership: ID exists")
+	ErrIDNotFound       = errors.New("membership: ID not found")
+	ErrPeerURLexists    = errors.New("membership: peerURL exists")
+	ErrMemberNotLearner = errors.New("membership: can only promote a learner member")
+	ErrTooManyLearners  = errors.New("membership: too many learner members in cluster")
+)
+
+func isKeyNotFound(err error) bool {
+	e, ok := err.(*v2error.Error)
+	return ok && e.ErrorCode == v2error.EcodeKeyNotFound
+}