diff --git a/vendor/github.com/coreos/etcd/pkg/logutil/zap_raft.go b/vendor/github.com/coreos/etcd/pkg/logutil/zap_raft.go
new file mode 100644
index 0000000..012d688
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/pkg/logutil/zap_raft.go
@@ -0,0 +1,102 @@
+// 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 (
+	"errors"
+
+	"github.com/coreos/etcd/raft"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// NewRaftLogger builds "raft.Logger" from "*zap.Config".
+func NewRaftLogger(lcfg *zap.Config) (raft.Logger, error) {
+	if lcfg == nil {
+		return nil, errors.New("nil zap.Config")
+	}
+	lg, err := lcfg.Build(zap.AddCallerSkip(1)) // to annotate caller outside of "logutil"
+	if err != nil {
+		return nil, err
+	}
+	return &zapRaftLogger{lg: lg, sugar: lg.Sugar()}, nil
+}
+
+// NewRaftLoggerZap converts "*zap.Logger" to "raft.Logger".
+func NewRaftLoggerZap(lg *zap.Logger) raft.Logger {
+	return &zapRaftLogger{lg: lg, sugar: lg.Sugar()}
+}
+
+// NewRaftLoggerFromZapCore creates "raft.Logger" from "zap.Core"
+// and "zapcore.WriteSyncer".
+func NewRaftLoggerFromZapCore(cr zapcore.Core, syncer zapcore.WriteSyncer) raft.Logger {
+	// "AddCallerSkip" to annotate caller outside of "logutil"
+	lg := zap.New(cr, zap.AddCaller(), zap.AddCallerSkip(1), zap.ErrorOutput(syncer))
+	return &zapRaftLogger{lg: lg, sugar: lg.Sugar()}
+}
+
+type zapRaftLogger struct {
+	lg    *zap.Logger
+	sugar *zap.SugaredLogger
+}
+
+func (zl *zapRaftLogger) Debug(args ...interface{}) {
+	zl.sugar.Debug(args...)
+}
+
+func (zl *zapRaftLogger) Debugf(format string, args ...interface{}) {
+	zl.sugar.Debugf(format, args...)
+}
+
+func (zl *zapRaftLogger) Error(args ...interface{}) {
+	zl.sugar.Error(args...)
+}
+
+func (zl *zapRaftLogger) Errorf(format string, args ...interface{}) {
+	zl.sugar.Errorf(format, args...)
+}
+
+func (zl *zapRaftLogger) Info(args ...interface{}) {
+	zl.sugar.Info(args...)
+}
+
+func (zl *zapRaftLogger) Infof(format string, args ...interface{}) {
+	zl.sugar.Infof(format, args...)
+}
+
+func (zl *zapRaftLogger) Warning(args ...interface{}) {
+	zl.sugar.Warn(args...)
+}
+
+func (zl *zapRaftLogger) Warningf(format string, args ...interface{}) {
+	zl.sugar.Warnf(format, args...)
+}
+
+func (zl *zapRaftLogger) Fatal(args ...interface{}) {
+	zl.sugar.Fatal(args...)
+}
+
+func (zl *zapRaftLogger) Fatalf(format string, args ...interface{}) {
+	zl.sugar.Fatalf(format, args...)
+}
+
+func (zl *zapRaftLogger) Panic(args ...interface{}) {
+	zl.sugar.Panic(args...)
+}
+
+func (zl *zapRaftLogger) Panicf(format string, args ...interface{}) {
+	zl.sugar.Panicf(format, args...)
+}