Implement InstanceExistsByProviderID() for cloud providers

Fix kubernetes#51406
If cloud providers(like aws, gce etc...) implement ExternalID()
and support getting instance by ProviderID , they also implement
InstanceExistsByProviderID().

pkg/cloudprovider/providers/openstack/openstack_instances.go

@@ -116,7 +116,25 @@ func (i *Instances) ExternalID(name types.NodeName) (string, error) {
 // InstanceExistsByProviderID returns true if the instance with the given provider id still exists and is running.
 // If false is returned with no error, the instance will be immediately deleted by the cloud controller manager.
 func (i *Instances) InstanceExistsByProviderID(providerID string) (bool, error) {
-	return false, cloudprovider.NotImplemented
+	instanceID, err := instanceIDFromProviderID(providerID)
+	if err != nil {
+		return false, err
+	}
+
+	server, err := servers.Get(i.compute, instanceID).Extract()
+	if err != nil {
+		if isNotFound(err) {
+			return false, nil
+		}
+		return false, err
+	}
+
+	if server.Status != "ACTIVE" {
+		glog.Warningf("the instance %s is not active", instanceID)
+		return false, nil
+	}
+
+	return true, nil
 }
 
 // InstanceID returns the kubelet's cloud provider ID.