Merge pull request #2801 from afbjorklund/rtc-warning

Avoid spamming the log when /dev/rtc does not exist

Author: AkihiroSuda

pkg/guestagent/guestagent_linux.go

@@ -324,6 +324,11 @@ const deltaLimit = 2 * time.Second
 
 func (a *agent) fixSystemTimeSkew() {
 	for {
+		ok, err := timesync.HasRTC()
+		if !ok {
+			logrus.Warnf("fixSystemTimeSkew: error: %s", err.Error())
+			break
+		}
 		ticker := time.NewTicker(10 * time.Second)
 		for now := range ticker.C {
 			rtc, err := timesync.GetRTCTime()

pkg/guestagent/timesync/timesync_linux.go

@@ -1,6 +1,7 @@
 package timesync
 
 import (
+	"errors"
 	"os"
 	"time"
 
@@ -9,6 +10,11 @@ import (
 
 const rtc = "/dev/rtc"
 
+func HasRTC() (bool, error) {
+	_, err := os.Stat(rtc)
+	return !errors.Is(err, os.ErrNotExist), err
+}
+
 func GetRTCTime() (t time.Time, err error) {
 	f, err := os.Open(rtc)
 	if err != nil {