add all files from Hong

logger/logger.go

@@ -0,0 +1,46 @@
+// Copyright 2018-present the CoreDHCP Authors. All rights reserved
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package logger
+
+import (
+	"io"
+	"sync"
+
+	log_prefixed "github.com/chappjc/logrus-prefix"
+	"github.com/rifflock/lfshook"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	globalLogger   *logrus.Logger
+	getLoggerMutex sync.Mutex
+)
+
+// GetLogger returns a configured logger instance
+func GetLogger(prefix string) *logrus.Entry {
+	if prefix == "" {
+		prefix = "<no prefix>"
+	}
+	if globalLogger == nil {
+		getLoggerMutex.Lock()
+		defer getLoggerMutex.Unlock()
+		logger := logrus.New()
+		logger.SetFormatter(&log_prefixed.TextFormatter{
+			FullTimestamp: true,
+		})
+		globalLogger = logger
+	}
+	return globalLogger.WithField("prefix", prefix)
+}
+
+// WithFile logs to the specified file in addition to the existing output.
+func WithFile(log *logrus.Entry, logfile string) {
+	log.Logger.AddHook(lfshook.NewHook(logfile, &logrus.TextFormatter{}))
+}
+
+// WithNoStdOutErr disables logging to stdout/stderr.
+func WithNoStdOutErr(log *logrus.Entry) {
+	log.Logger.SetOutput(io.Discard)
+}