[VOL-2312] Logging - Integrate voltctl with new etcd-based dynamic loglevel mechanism. Testing is in progress

Change-Id: I2e13bb79008c9a49ebb6f58e575f51efebe6dbfd
diff --git a/vendor/go.etcd.io/etcd/pkg/logutil/discard_logger.go b/vendor/go.etcd.io/etcd/pkg/logutil/discard_logger.go
new file mode 100644
index 0000000..81b0a9d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/logutil/discard_logger.go
@@ -0,0 +1,46 @@
+// 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 (
+	"log"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+// assert that "discardLogger" satisfy "Logger" interface
+var _ Logger = &discardLogger{}
+
+// NewDiscardLogger returns a new Logger that discards everything except "fatal".
+func NewDiscardLogger() Logger { return &discardLogger{} }
+
+type discardLogger struct{}
+
+func (l *discardLogger) Info(args ...interface{})                    {}
+func (l *discardLogger) Infoln(args ...interface{})                  {}
+func (l *discardLogger) Infof(format string, args ...interface{})    {}
+func (l *discardLogger) Warning(args ...interface{})                 {}
+func (l *discardLogger) Warningln(args ...interface{})               {}
+func (l *discardLogger) Warningf(format string, args ...interface{}) {}
+func (l *discardLogger) Error(args ...interface{})                   {}
+func (l *discardLogger) Errorln(args ...interface{})                 {}
+func (l *discardLogger) Errorf(format string, args ...interface{})   {}
+func (l *discardLogger) Fatal(args ...interface{})                   { log.Fatal(args...) }
+func (l *discardLogger) Fatalln(args ...interface{})                 { log.Fatalln(args...) }
+func (l *discardLogger) Fatalf(format string, args ...interface{})   { log.Fatalf(format, args...) }
+func (l *discardLogger) V(lvl int) bool {
+	return false
+}
+func (l *discardLogger) Lvl(lvl int) grpclog.LoggerV2 { return l }