change pod from a node to another in runtime about java HOT 12 CLOSED

public void updateNodeSelector(V1Pod pod) throws ApiException {		
	pod.getSpec().setNodeSelector(this.nodeSelector);
	pod.getSpec().setNodeName("swarm5");
		
	String podName = pod.getMetadata().getName();
	String podNamespace = pod.getMetadata().getNamespace();		
		
	K8Instance.getInstance().patchNamespacedPod(podName, podNamespace, null, null);
	System.out.println("and now it is on node: "+pod.getSpec().getNodeName());
		
}

public class Verify {
	public static void main(String[] args) throws FileNotFoundException, ApiException {
		//setting the environment
		final String pathToGfadsConfigFile = "/home/vinicius/Documentos/gfads-test.config";
		FileReader gfadsConfigFile = new FileReader(pathToGfadsConfigFile);
		KubeConfig kc = KubeConfig.loadKubeConfig(gfadsConfigFile);
		ApiClient client = Config.fromConfig(kc);
		Configuration.setDefaultApiClient(client);
		
		//getting the environment
		CoreV1Api core = new CoreV1Api();
		AppsV1beta1Api beta = new AppsV1beta1Api();
		
		//dealing with pods		
		ObjectsDealer k8objects = new ObjectsDealer();
		String podName = "kube-proxy-8ktf4";
		V1Pod pod = k8objects.findPod(core,podName);
		
		//setting labels to pods
		String key = "key";
		String operator = "In";
		String value = "value";
		pod = k8objects.setLabelsToPods(core, podName, key, podName, operator, Collections.singletonList(value));
		System.out.println("got here");
		
		core.patchNamespacedPod(podName, pod.getMetadata().getNamespace(), pod, null);
		
		System.out.println("it works");		
	}
}

got here
Exception in thread "main" io.kubernetes.client.ApiException: Internal Server Error
	at io.kubernetes.client.ApiClient.handleResponse(ApiClient.java:882)
	at io.kubernetes.client.ApiClient.execute(ApiClient.java:798)
	at io.kubernetes.client.apis.CoreV1Api.patchNamespacedPodWithHttpInfo(CoreV1Api.java:19235)
	at io.kubernetes.client.apis.CoreV1Api.patchNamespacedPod(CoreV1Api.java:19218)
	at mainTest.Verify.main(Verify.java:44)

package k8_object;

import java.util.List;

import io.kubernetes.client.ApiException;
import io.kubernetes.client.apis.CoreV1Api;
import io.kubernetes.client.models.V1LabelSelector;
import io.kubernetes.client.models.V1LabelSelectorRequirement;
import io.kubernetes.client.models.V1Pod;
import io.kubernetes.client.models.V1PodList;

public class ObjectsDealer {

	public V1Pod findPod(CoreV1Api core, String podName) throws ApiException {
		V1PodList list = core.listPodForAllNamespaces(null, null, null, null, null, null);
		for (V1Pod item : list.getItems()) 
			if(item.getMetadata().getName().equalsIgnoreCase(podName))
				return item;
		return null;
	}

	public V1Pod setLabelsToPods(CoreV1Api core, String podName, String key, String matchLabelsItem, String operator, List<String> values) throws ApiException {
		//setting label selector and label requirement. I still do not know what is a requirement of their difference
		V1LabelSelector selector = new V1LabelSelector();
		V1LabelSelectorRequirement requirement = new V1LabelSelectorRequirement();
		selector.putMatchLabelsItem(key, matchLabelsItem);
		requirement.setKey(key);
		requirement.setOperator(operator);
		requirement.setValues(values);
		
		V1Pod pod = setLabels(core, podName, selector, requirement);		
		return pod;
	}
	
	private V1Pod setLabels(CoreV1Api core, String podName, V1LabelSelector selector, V1LabelSelectorRequirement requirement) throws ApiException {
		V1Pod pod = this.findPod(core, podName);
		pod.getMetadata().setLabels(selector.getMatchLabels());
		//I Still don't know why the requirement is here. It is useless.
		return pod;
	}
}

Exception when calling CoreV1Api#patchNamespacedPod
io.kubernetes.client.ApiException: Missing the required parameter 'body' when calling patchNamespacedPod(Async)
	at io.kubernetes.client.apis.CoreV1Api.patchNamespacedPodValidateBeforeCall(CoreV1Api.java:19194)
	at io.kubernetes.client.apis.CoreV1Api.patchNamespacedPodWithHttpInfo(CoreV1Api.java:19233)
	at io.kubernetes.client.apis.CoreV1Api.patchNamespacedPod(CoreV1Api.java:19218)
	at main.Example.main(Example.java:40)

package main;

import java.io.FileNotFoundException;
import java.io.FileReader;

import io.kubernetes.client.ApiClient;
import io.kubernetes.client.ApiException;
import io.kubernetes.client.Configuration;
import io.kubernetes.client.apis.CoreV1Api;
import io.kubernetes.client.auth.ApiKeyAuth;
import io.kubernetes.client.models.V1Pod;
import io.kubernetes.client.util.Config;
import io.kubernetes.client.util.KubeConfig;

/**
 * patch pod example from 
 * https://github.com/kubernetes-client/java/blob/master/kubernetes/docs/CoreV1Api.md#patchNamespacedPod
 * @author vinicius
 *
 */
public class Example {
	public static void main(String[] args) throws FileNotFoundException {
		//setting the environment
		final String pathToGfadsConfigFile = "/home/vinicius/Documentos/gfads-test.config";
		FileReader gfadsConfigFile = new FileReader(pathToGfadsConfigFile);
		KubeConfig kc = KubeConfig.loadKubeConfig(gfadsConfigFile);
		ApiClient client = Config.fromConfig(kc);
		Configuration.setDefaultApiClient(client);


		CoreV1Api apiInstance = new CoreV1Api();

		String name = "name_example"; // String | name of the Pod
		String namespace = "namespace_example"; // String | object name and auth scope, such as for teams and projects
		Object body = null; // Object | 
		String pretty = "pretty_example"; // String | If 'true', then the output is pretty printed.


		try {
			V1Pod result = apiInstance.patchNamespacedPod(name, namespace, body, pretty);
			System.out.println(result);
		} catch (ApiException e) {
			System.err.println("Exception when calling CoreV1Api#patchNamespacedPod");
			e.printStackTrace();
		}

	}
}