internal/router: wait ntp synced on Synology

internal/router/ntp/ntp.go

@@ -1,16 +1,20 @@
 package ntp
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
+	"os/exec"
 	"time"
 
-	"github.com/Control-D-Inc/ctrld/internal/router/nvram"
 	"tailscale.com/logtail/backoff"
+
+	"github.com/Control-D-Inc/ctrld/internal/router/nvram"
 )
 
-func Wait() error {
+// WaitNvram waits NTP synced by checking "ntp_ready" value using nvram.
+func WaitNvram() error {
 	// Wait until `ntp_ready=1` set.
 	b := backoff.NewBackoff("ntp.Wait", func(format string, args ...any) {}, 10*time.Second)
 	for {
@@ -24,3 +28,19 @@ func Wait() error {
 		b.BackOff(context.Background(), errors.New("ntp not ready"))
 	}
 }
+
+// WaitUpstart waits NTP synced by checking upstart task "ntpsync" is in "stop/waiting" state.
+func WaitUpstart() error {
+	// Wait until `initctl status ntpsync` returns stop state.
+	b := backoff.NewBackoff("ntp.WaitUpstart", func(format string, args ...any) {}, 10*time.Second)
+	for {
+		out, err := exec.Command("initctl", "status", "ntpsync").CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("exec.Command: %w", err)
+		}
+		if bytes.Contains(out, []byte("stop/waiting")) {
+			return nil
+		}
+		b.BackOff(context.Background(), errors.New("ntp not ready"))
+	}
+}