add configurable log file path

utils/logger.go

@@ -8,14 +8,25 @@ import (
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
-var consoleWriter = zerolog.ConsoleWriter{Out: os.Stdout, TimeFormat: time.RFC3339}
-var fileWriter = &lumberjack.Logger{
-	Filename:   "/var/log/local-ip.sh.log",
-	MaxBackups: 3,
-	MaxSize:    1,    // megabytes
-	MaxAge:     1,    // days
-	Compress:   true, // disabled by default
-}
-var multi = zerolog.MultiLevelWriter(consoleWriter, fileWriter)
+const DefaultLogFile = "/var/log/local-ip.sh.log"
 
-var Logger = zerolog.New(multi).With().Timestamp().Logger()
+var consoleWriter = zerolog.ConsoleWriter{Out: os.Stdout, TimeFormat: time.RFC3339}
+
+var Logger = zerolog.New(consoleWriter).With().Timestamp().Logger()
+
+func InitLogger(logFile string) {
+	if logFile == "" {
+		logFile = DefaultLogFile
+	}
+
+	fileWriter := &lumberjack.Logger{
+		Filename:   logFile,
+		MaxBackups: 3,
+		MaxSize:    1,
+		MaxAge:     1,
+		Compress:   true,
+	}
+
+	multi := zerolog.MultiLevelWriter(consoleWriter, fileWriter)
+	Logger = zerolog.New(multi).With().Timestamp().Logger()
+}