func()

in pkg/controllers/workapplier/preprocess.go [448:534]

• 63 lines of code
• 11 McCabe index (conditional complexity)

func (r *Reconciler) removeOneLeftOverManifest(
	ctx context.Context,
	leftOverManifest fleetv1beta1.AppliedResourceMeta,
	expectedAppliedWorkOwnerRef *metav1.OwnerReference,
) error {
	// Build the GVR.
	gvr := schema.GroupVersionResource{
		Group:    leftOverManifest.Group,
		Version:  leftOverManifest.Version,
		Resource: leftOverManifest.Resource,
	}
	manifestNamespace := leftOverManifest.Namespace
	manifestName := leftOverManifest.Name

	inMemberClusterObj, err := r.spokeDynamicClient.
		Resource(gvr).
		Namespace(manifestNamespace).
		Get(ctx, manifestName, metav1.GetOptions{})
	switch {
	case err != nil && apierrors.IsNotFound(err):
		// The object has been deleted from the member cluster; no further action is needed.
		return nil
	case err != nil:
		// Failed to retrieve the object from the member cluster.
		wrappedErr := controller.NewAPIServerError(true, err)
		return fmt.Errorf("failed to retrieve the object from the member cluster (gvr=%+v, manifestObj=%+v): %w", gvr, klog.KRef(manifestNamespace, manifestName), wrappedErr)
	case inMemberClusterObj.GetDeletionTimestamp() != nil:
		// The object has been marked for deletion; no further action is needed.
		return nil
	}

	// There are occasions, though rare, where the object has the same GVR + namespace + name
	// combo but is not the applied object Fleet tries to find. This could happen if the object
	// has been deleted and then re-created manually without Fleet's acknowledgement. In such cases
	// Fleet would ignore the object, and this is not registered as an error.
	if !isInMemberClusterObjectDerivedFromManifestObj(inMemberClusterObj, expectedAppliedWorkOwnerRef) {
		// The object is not derived from the manifest object.
		klog.V(2).InfoS("The object to remove is not derived from the manifest object; will not proceed with the removal",
			"gvr", gvr, "manifestObj",
			klog.KRef(manifestNamespace, manifestName), "inMemberClusterObj", klog.KObj(inMemberClusterObj),
			"expectedAppliedWorkOwnerRef", *expectedAppliedWorkOwnerRef)
		return nil
	}

	switch {
	case len(inMemberClusterObj.GetOwnerReferences()) > 1:
		// Fleet is not the sole owner of the object; in this case, Fleet will only drop the
		// ownership.
		klog.V(2).InfoS("The object to remove is co-owned by other sources; Fleet will drop the ownership",
			"gvr", gvr, "manifestObj",
			klog.KRef(manifestNamespace, manifestName), "inMemberClusterObj", klog.KObj(inMemberClusterObj),
			"expectedAppliedWorkOwnerRef", *expectedAppliedWorkOwnerRef)
		removeOwnerRef(inMemberClusterObj, expectedAppliedWorkOwnerRef)
		if _, err := r.spokeDynamicClient.Resource(gvr).Namespace(manifestNamespace).Update(ctx, inMemberClusterObj, metav1.UpdateOptions{}); err != nil && !apierrors.IsNotFound(err) {
			// Failed to drop the ownership.
			wrappedErr := controller.NewAPIServerError(false, err)
			return fmt.Errorf("failed to drop the ownership of the object (gvr=%+v, manifestObj=%+v, inMemberClusterObj=%+v, expectedAppliedWorkOwnerRef=%+v): %w",
				gvr, klog.KRef(manifestNamespace, manifestName), klog.KObj(inMemberClusterObj), *expectedAppliedWorkOwnerRef, wrappedErr)
		}
	default:
		// Fleet is the sole owner of the object; in this case, Fleet will delete the object.
		klog.V(2).InfoS("The object to remove is solely owned by Fleet; Fleet will delete the object",
			"gvr", gvr, "manifestObj",
			klog.KRef(manifestNamespace, manifestName), "inMemberClusterObj", klog.KObj(inMemberClusterObj),
			"expectedAppliedWorkOwnerRef", *expectedAppliedWorkOwnerRef)
		inMemberClusterObjUID := inMemberClusterObj.GetUID()
		deleteOpts := metav1.DeleteOptions{
			Preconditions: &metav1.Preconditions{
				// Add a UID pre-condition to guard against the case where the object has changed
				// right before the deletion request is sent.
				//
				// Technically speaking resource version based concurrency control should also be
				// enabled here; Fleet drops the check to avoid conflicts; this is safe as the Fleet
				// ownership is considered to be a reserved field and other changes on the object are
				// irrelevant to this step.
				UID: &inMemberClusterObjUID,
			},
		}
		if err := r.spokeDynamicClient.Resource(gvr).Namespace(manifestNamespace).Delete(ctx, manifestName, deleteOpts); err != nil && !apierrors.IsNotFound(err) {
			// Failed to delete the object from the member cluster.
			wrappedErr := controller.NewAPIServerError(false, err)
			return fmt.Errorf("failed to delete the object (gvr=%+v, manifestObj=%+v, inMemberClusterObj=%+v, expectedAppliedWorkOwnerRef=%+v): %w",
				gvr, klog.KRef(manifestNamespace, manifestName), klog.KObj(inMemberClusterObj), *expectedAppliedWorkOwnerRef, wrappedErr)
		}
	}
	return nil
}