@Override
        public void onAdd(final Pod obj) {
            updateRemoteInstances(obj, ADDED);
        }
Read collector pod info from api-server of kubernetes, then using all containerIp list to construct the list of
{@link RemoteInstance}.
oap-server/server-cluster-plugin/cluster-kubernetes-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/kubernetes/KubernetesCoordinator.java