// GetServerSupportedSMPatchVersionFromFactory is a wrapper of GetServerSupportedSMPatchVersion(),
// It takes a Factory, returns the max version the server supports.
func GetServerSupportedSMPatchVersionFromFactory(f Factory) (strategicpatch.StrategicMergePatchVersion, error) {
	clientSet, err := f.ClientSet()
	if err != nil {
		return strategicpatch.Unknown, err
	}
	return strategicpatch.GetServerSupportedSMPatchVersion(clientSet.Discovery())
}
func (nsu *nodeStatusUpdater) UpdateNodeStatuses() error {
	smPatchVersion, err := strategicpatch.GetServerSupportedSMPatchVersion(nsu.kubeClient.Discovery())
	if err != nil {
		return err
	}
	nodesToUpdate := nsu.actualStateOfWorld.GetVolumesToReportAttached()
	for nodeName, attachedVolumes := range nodesToUpdate {
		nodeObj, exists, err := nsu.nodeInformer.GetStore().GetByKey(string(nodeName))
		if nodeObj == nil || !exists || err != nil {
			// If node does not exist, its status cannot be updated, log error and
			// reset flag statusUpdateNeeded back to true to indicate this node status
			// needs to be udpated again
			glog.V(2).Infof(
				"Could not update node status. Failed to find node %q in NodeInformer cache. %v",
				nodeName,
				err)
			nsu.actualStateOfWorld.SetNodeStatusUpdateNeeded(nodeName)
			continue
		}

		clonedNode, err := conversion.NewCloner().DeepCopy(nodeObj)
		if err != nil {
			return fmt.Errorf("error cloning node %q: %v",
				nodeName,
				err)
		}

		node, ok := clonedNode.(*api.Node)
		if !ok || node == nil {
			return fmt.Errorf(
				"failed to cast %q object %#v to Node",
				nodeName,
				clonedNode)
		}

		oldData, err := json.Marshal(node)
		if err != nil {
			return fmt.Errorf(
				"failed to Marshal oldData for node %q. %v",
				nodeName,
				err)
		}

		node.Status.VolumesAttached = attachedVolumes

		newData, err := json.Marshal(node)
		if err != nil {
			return fmt.Errorf(
				"failed to Marshal newData for node %q. %v",
				nodeName,
				err)
		}

		patchBytes, err :=
			strategicpatch.CreateStrategicMergePatch(oldData, newData, node, smPatchVersion)
		if err != nil {
			return fmt.Errorf(
				"failed to CreateStrategicMergePatch for node %q. %v",
				nodeName,
				err)
		}

		_, err = nsu.kubeClient.Core().Nodes().PatchStatus(string(nodeName), patchBytes)
		if err != nil {
			// If update node status fails, reset flag statusUpdateNeeded back to true
			// to indicate this node status needs to be udpated again
			nsu.actualStateOfWorld.SetNodeStatusUpdateNeeded(nodeName)
			return fmt.Errorf(
				"failed to kubeClient.Core().Nodes().Patch for node %q. %v",
				nodeName,
				err)
		}
		glog.V(2).Infof(
			"Updating status for node %q succeeded. patchBytes: %q VolumesAttached: %v",
			nodeName,
			string(patchBytes),
			node.Status.VolumesAttached)

	}
	return nil
}