No warning(s) in the output file with -quiet option. Report command (#885)

util/logutil.go

@@ -44,7 +44,6 @@ func init() {
 func NewCustomLogger(c config.ServerInfo) *logrus.Entry {
 	log := logrus.New()
 	log.Formatter = &formatter.TextFormatter{MsgAnsiColor: c.LogMsgAnsiColor}
-	log.Out = os.Stderr
 	log.Level = logrus.InfoLevel
 	if config.Conf.Debug {
 		log.Level = logrus.DebugLevel
@@ -62,6 +61,18 @@ func NewCustomLogger(c config.ServerInfo) *logrus.Entry {
 		}
 	}
 
+	// Only log to a file if quiet mode enabled
+	if config.Conf.Quiet {
+		logFile := logDir + "/vuls.log"
+		if file, err := os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644); err == nil {
+			log.Out = file
+		} else {
+			log.Errorf("Failed to create log file. path: %s, err: %s", logFile, err)
+		}
+	} else {
+		log.Out = os.Stderr
+	}
+
 	whereami := "localhost"
 	if 0 < len(c.ServerName) {
 		whereami = c.GetServerName()