func()

in pkg/controllers/clusterresourceplacement/resource_selector.go [167:236]
62 lines of code
12 McCabe index (conditional complexity)

func (r *Reconciler) fetchClusterScopedResources(selector fleetv1beta1.ClusterResourceSelector, placeName string) ([]runtime.Object, error) {
	klog.V(2).InfoS("start to fetch the cluster scoped resources by the selector", "selector", selector)
	gk := schema.GroupKind{
		Group: selector.Group,
		Kind:  selector.Kind,
	}
	restMapping, err := r.RestMapper.RESTMapping(gk, selector.Version)
	if err != nil {
		return nil, controller.NewUserError(fmt.Errorf("invalid placement %s, failed to get GVR of the selector: %w", placeName, err))
	}
	gvr := restMapping.Resource
	gvk := schema.GroupVersionKind{
		Group:   selector.Group,
		Version: selector.Version,
		Kind:    selector.Kind,
	}
	if !r.InformerManager.IsClusterScopedResources(gvk) {
		return nil, controller.NewUserError(fmt.Errorf("invalid placement %s: %+v is not a cluster scoped resource", placeName, restMapping.Resource))
	}
	if !r.InformerManager.IsInformerSynced(gvr) {
		return nil, controller.NewExpectedBehaviorError(fmt.Errorf("informer cache for %+v is not synced yet", restMapping.Resource))
	}

	lister := r.InformerManager.Lister(gvr)
	// TODO: validator should enforce the mutual exclusiveness between the `name` and `labelSelector` fields
	if len(selector.Name) != 0 {
		obj, err := lister.Get(selector.Name)
		if err != nil {
			klog.ErrorS(err, "cannot get the resource", "gvr", gvr, "name", selector.Name)
			return nil, controller.NewAPIServerError(true, client.IgnoreNotFound(err))
		}
		uObj := obj.DeepCopyObject().(*unstructured.Unstructured)
		if uObj.GetDeletionTimestamp() != nil {
			// skip a to be deleted namespace
			klog.V(2).InfoS("skip the deleting cluster scoped resources by the selector",
				"selector", selector, "placeName", placeName, "resource name", uObj.GetName())
			return []runtime.Object{}, nil
		}
		return []runtime.Object{obj}, nil
	}

	var labelSelector labels.Selector
	if selector.LabelSelector == nil {
		labelSelector = labels.Everything()
	} else {
		// TODO: validator should enforce the validity of the labelSelector
		labelSelector, err = metav1.LabelSelectorAsSelector(selector.LabelSelector)
		if err != nil {
			return nil, controller.NewUnexpectedBehaviorError(fmt.Errorf("cannot convert the label selector to a selector: %w", err))
		}
	}
	var selectedObjs []runtime.Object
	objects, err := lister.List(labelSelector)
	if err != nil {
		return nil, controller.NewAPIServerError(true, fmt.Errorf("cannot list all the objects: %w", err))
	}
	// go ahead and claim all objects by adding a finalizer and insert the placement in its annotation
	for i := 0; i < len(objects); i++ {
		uObj := objects[i].DeepCopyObject().(*unstructured.Unstructured)
		if uObj.GetDeletionTimestamp() != nil {
			// skip a to be deleted namespace
			klog.V(2).InfoS("skip the deleting cluster scoped resources by the selector",
				"selector", selector, "placeName", placeName, "resource name", uObj.GetName())
			continue
		}
		selectedObjs = append(selectedObjs, objects[i])
	}

	return selectedObjs, nil
}