Just curious about REST and ProxyREST in karmada

[NickYadance]

This is just some dummy question related to source code, but i've been searching a while still cannot find the answer. Hope someone with the knowledge can tell it.

The REST implements the Redirector interface , so it can proxy(redirect) requests.

karmada/pkg/registry/cluster/storage/storage.go

Lines 107 to 124 in bd5692f

	var _ = rest.Redirector(&REST{})
	// ResourceLocation returns a URL to which one can send traffic for the specified cluster.
	func (r *REST) ResourceLocation(ctx context.Context, name string) (*url.URL, http.RoundTripper, error) {
	cluster, err := r.getCluster(ctx, name)
	if err != nil {
	return nil, nil, err
	}
	secretGetter := func(_ context.Context, namespace, name string) (*corev1.Secret, error) {
	return r.secretLister.Secrets(namespace).Get(name)
	}
	tlsConfig, err := proxy.GetTLSConfigForCluster(ctx, cluster, secretGetter)
	if err != nil {
	return nil, nil, err
	}
	return proxy.Location(cluster, tlsConfig)

The ProxyREST also does some proxy stuff related to proxy, with cluster/proxy prefix.

karmada/pkg/registry/cluster/storage/proxy.go

Lines 41 to 50 in bd5692f

	type ProxyREST struct {
	restConfig *restclient.Config
	kubeClient kubernetes.Interface
	secretLister listcorev1.SecretLister
	clusterGetter func(ctx context.Context, name string) (*clusterapis.Cluster, error)
	clusterLister func(ctx context.Context) (*clusterapis.ClusterList, error)
	karmadaLocation *url.URL
	karmadaTransPort http.RoundTripper
	}

I wonder what's the difference between these two, and when will them be applied ?