Fix k8s api bugs (#1842)

    }

    @Override public List<RemoteInstance> queryRemoteNodes() {

        logger.debug("Query kubernetes remote nodes: {}", cache);

        return Lists.newArrayList(cache.values());

    }

}

import io.kubernetes.client.util.Config;

import io.kubernetes.client.util.Watch;

import java.io.IOException;

import java.util.Collections;

import java.util.Iterator;

import java.util.concurrent.TimeUnit;

import org.apache.skywalking.oap.server.cluster.plugin.kubernetes.Event;

import org.apache.skywalking.oap.server.cluster.plugin.kubernetes.ReusableWatch;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * Watch the api {@literal https://v1-9.docs.kubernetes.io/docs/reference/generated/kubernetes-api/v1.9/#watch-64}.

 */

public class NamespacedPodListWatch implements ReusableWatch<Event> {

    private final CoreV1Api api = new CoreV1Api();

    private static final Logger logger = LoggerFactory.getLogger(NamespacedPodListWatch.class);

    private final String namespace;

        }

        client.getHttpClient().setReadTimeout(watchTimeoutSeconds, TimeUnit.SECONDS);

        Configuration.setDefaultApiClient(client);

        CoreV1Api api = new CoreV1Api();

        try {

            watch = Watch.createWatch(

                client,

                    null, labelSelector, Integer.MAX_VALUE,null,null, Boolean.TRUE,

                    null, null),

                new TypeToken<Watch.Response<V1Pod>>() { }.getType());

        } catch (ApiException e) {

        } catch (final ApiException e) {

            logger.error("code:{} header:{} body:{}", e.getCode(), e.getResponseHeaders(), e.getResponseBody());

            throw new RuntimeException(e.getMessage(), e);

        }

    }

    @Override public Iterator<Event> iterator() {

        try {

            return Iterators.transform(watch.iterator(), response -> {

                if (response == null) {

                    throw new NullPointerException("Original event is null");

                }

                return new Event(response.type, response.object.getMetadata().getUid(), response.object.getStatus().getPodIP());

            });

        } catch (final RuntimeException exp) {

            logger.trace("Runtime exception", exp);

        }

        return Collections.emptyIterator();

    }

}