add configurable log file path

cmd/root.go

@@ -24,6 +24,8 @@ var command = &cobra.Command{
 		viper.SetEnvPrefix("XIP")
 		viper.AutomaticEnv()
 
+		utils.InitLogger(viper.GetString("log-file"))
+
 		email := viper.GetString("Email")
 		_, err := mail.ParseAddress(email)
 		if err != nil {
@@ -84,6 +86,9 @@ var command = &cobra.Command{
 }
 
 func Execute() {
+	command.Flags().String("log-file", utils.DefaultLogFile, "Path to log file")
+	viper.BindPFlag("log-file", command.Flags().Lookup("log-file"))
+
 	command.Flags().Uint("dns-port", 53, "Port for the DNS server")
 	viper.BindPFlag("dns-port", command.Flags().Lookup("dns-port"))
 

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()
+}