Questions about error return in ads_envent.go

[LiZhenCheng9527]

Please provide an in-depth description of the question you have:

func (svc *ServiceEvent) handleCdsResponse(rsp *service_discovery_v3.DiscoveryResponse) error {
	var (
		err     error
		cluster = &config_cluster_v3.Cluster{}
	)

	current := sets.New[string]()
	for _, resource := range rsp.GetResources() {
		if err = anypb.UnmarshalTo(resource, cluster, proto.UnmarshalOptions{}); err != nil {
			continue
		}
		current.Insert(cluster.GetName())
		// compare part[0] CDS now
		// Cluster_EDS need compare tow parts, compare part[1] EDS in EDS handler
		apiStatus := core_v2.ApiStatus_UPDATE
		newHash := hash.Sum64String(resource.String())
		if newHash != svc.DynamicLoader.ClusterCache.GetCdsHash(cluster.GetName()) {
			svc.DynamicLoader.ClusterCache.SetCdsHash(cluster.GetName(), newHash)
			log.Debugf("[CreateApiClusterByCds] update cluster %s, status %d, cluster.type %v",
				cluster.GetName(), apiStatus, cluster.GetType())
			svc.DynamicLoader.CreateApiClusterByCds(apiStatus, cluster)
		} else {
			log.Debugf("unchanged cluster %s", cluster.GetName())
		}
	}

	removed := svc.DynamicLoader.ClusterCache.GetResourceNames().Difference(current)
	for key := range removed {
		svc.DynamicLoader.UpdateApiClusterStatus(key, core_v2.ApiStatus_DELETE)
	}

	// TODO: maybe we don't need to wait until all clusters ready before loading, like cluster delete

	if len(svc.DynamicLoader.clusterNames) > 0 {
		svc.rqt = newAdsRequest(resource_v3.EndpointType, svc.DynamicLoader.clusterNames)
		svc.DynamicLoader.clusterNames = nil
	} else {
		svc.DynamicLoader.ClusterCache.Flush()
	}
	return nil
}

In the above code Kmesh processes the cds response.
However, the error during processing is not returned, but just a return nil in the end.

func (svc *ServiceEvent) processAdsResponse(rsp *service_discovery_v3.DiscoveryResponse) {
	var err error

	log.Debugf("handle ads response, %#v\n", rsp.GetTypeUrl())

	svc.ack = newAckRequest(rsp)
	if rsp.GetResources() == nil {
		return
	}

	switch rsp.GetTypeUrl() {
	case resource_v3.ClusterType:
		err = svc.handleCdsResponse(rsp)
	case resource_v3.EndpointType:
		err = svc.handleEdsResponse(rsp)
	case resource_v3.ListenerType:
		err = svc.handleLdsResponse(rsp)
	case resource_v3.RouteType:
		err = svc.handleRdsResponse(rsp)
	default:
		err = fmt.Errorf("unsupport type url %s", rsp.GetTypeUrl())
	}

	if err != nil {
		log.Error(err)
	}
}

So in the above function, won't the final error be nil?

What do you think about this question?:
I don't know if this is a bug, or if there is another way of passing error in xds.

Environment:

• Kmesh version: 0.2.0

[LiZhenCheng9527]

ads_envent.go