Utilize read lock for getLastObservedNodeAddresses

pkg/kubelet/kubelet.go

@@ -901,7 +901,7 @@ type Kubelet struct {
 	iptClient       utilipt.Interface
 	rootDirectory   string
 
-	lastObservedNodeAddressesMux sync.Mutex
+	lastObservedNodeAddressesMux sync.RWMutex
 	lastObservedNodeAddresses    []v1.NodeAddress
 
 	// onRepeatedHeartbeatFailure is called when a heartbeat operation fails more than once. optional.

pkg/kubelet/kubelet_node_status.go

@@ -510,8 +510,8 @@ func (kl *Kubelet) setLastObservedNodeAddresses(addresses []v1.NodeAddress) {
 	kl.lastObservedNodeAddresses = addresses
 }
 func (kl *Kubelet) getLastObservedNodeAddresses() []v1.NodeAddress {
-	kl.lastObservedNodeAddressesMux.Lock()
-	defer kl.lastObservedNodeAddressesMux.Unlock()
+	kl.lastObservedNodeAddressesMux.RLock()
+	defer kl.lastObservedNodeAddressesMux.RUnlock()
 	return kl.lastObservedNodeAddresses
 }