Fix Data Race in nodeshutdown restart

pkg/kubelet/nodeshutdown/nodeshutdown_manager_linux_test.go

@@ -21,6 +21,7 @@ package nodeshutdown
 import (
 	"fmt"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -329,15 +330,18 @@ func TestRestart(t *testing.T) {
 	syncNodeStatus := func() {}
 
 	var shutdownChan chan bool
+	var shutdownChanMut sync.Mutex
 	var connChan = make(chan struct{}, 1)
 
 	systemDbus = func() (dbusInhibiter, error) {
 		defer func() {
 			connChan <- struct{}{}
 		}()
-
-		shutdownChan = make(chan bool)
-		dbus := &fakeDbus{currentInhibitDelay: systemInhibitDelay, shutdownChan: shutdownChan, overrideSystemInhibitDelay: overrideSystemInhibitDelay}
+		ch := make(chan bool)
+		shutdownChanMut.Lock()
+		shutdownChan = ch
+		shutdownChanMut.Unlock()
+		dbus := &fakeDbus{currentInhibitDelay: systemInhibitDelay, shutdownChan: ch, overrideSystemInhibitDelay: overrideSystemInhibitDelay}
 		return dbus, nil
 	}
 
@@ -354,7 +358,9 @@ func TestRestart(t *testing.T) {
 		case <-connChan:
 		}
 
-		time.Sleep(time.Second)
+		time.Sleep(dbusReconnectPeriod)
+		shutdownChanMut.Lock()
 		close(shutdownChan)
+		shutdownChanMut.Unlock()
 	}
 }