diff --git a/vendor/go.etcd.io/etcd/pkg/logutil/logger.go b/vendor/go.etcd.io/etcd/pkg/logutil/logger.go
new file mode 100644
index 0000000..e7da80e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/logutil/logger.go
@@ -0,0 +1,64 @@
+// Copyright 2018 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 logutil
+
+import "google.golang.org/grpc/grpclog"
+
+// Logger defines logging interface.
+// TODO: deprecate in v3.5.
+type Logger interface {
+	grpclog.LoggerV2
+
+	// Lvl returns logger if logger's verbosity level >= "lvl".
+	// Otherwise, logger that discards everything.
+	Lvl(lvl int) grpclog.LoggerV2
+}
+
+// assert that "defaultLogger" satisfy "Logger" interface
+var _ Logger = &defaultLogger{}
+
+// NewLogger wraps "grpclog.LoggerV2" that implements "Logger" interface.
+//
+// For example:
+//
+//  var defaultLogger Logger
+//  g := grpclog.NewLoggerV2WithVerbosity(os.Stderr, os.Stderr, os.Stderr, 4)
+//  defaultLogger = NewLogger(g)
+//
+func NewLogger(g grpclog.LoggerV2) Logger { return &defaultLogger{g: g} }
+
+type defaultLogger struct {
+	g grpclog.LoggerV2
+}
+
+func (l *defaultLogger) Info(args ...interface{})                    { l.g.Info(args...) }
+func (l *defaultLogger) Infoln(args ...interface{})                  { l.g.Info(args...) }
+func (l *defaultLogger) Infof(format string, args ...interface{})    { l.g.Infof(format, args...) }
+func (l *defaultLogger) Warning(args ...interface{})                 { l.g.Warning(args...) }
+func (l *defaultLogger) Warningln(args ...interface{})               { l.g.Warning(args...) }
+func (l *defaultLogger) Warningf(format string, args ...interface{}) { l.g.Warningf(format, args...) }
+func (l *defaultLogger) Error(args ...interface{})                   { l.g.Error(args...) }
+func (l *defaultLogger) Errorln(args ...interface{})                 { l.g.Error(args...) }
+func (l *defaultLogger) Errorf(format string, args ...interface{})   { l.g.Errorf(format, args...) }
+func (l *defaultLogger) Fatal(args ...interface{})                   { l.g.Fatal(args...) }
+func (l *defaultLogger) Fatalln(args ...interface{})                 { l.g.Fatal(args...) }
+func (l *defaultLogger) Fatalf(format string, args ...interface{})   { l.g.Fatalf(format, args...) }
+func (l *defaultLogger) V(lvl int) bool                              { return l.g.V(lvl) }
+func (l *defaultLogger) Lvl(lvl int) grpclog.LoggerV2 {
+	if l.g.V(lvl) {
+		return l
+	}
+	return &discardLogger{}
+}