Develop Reference

API of Kubernetes in java: authentication error

I am developing a simple java app that show the pods of the cluster.
This is the app:
import io.kubernetes.client.openapi.ApiClient;
import io.kubernetes.client.openapi.ApiException;
import io.kubernetes.client.openapi.Configuration;
import io.kubernetes.client.openapi.apis.CoreV1Api;
import io.kubernetes.client.openapi.models.V1Pod;
import io.kubernetes.client.openapi.models.V1PodList;
import io.kubernetes.client.util.ClientBuilder;
import io.kubernetes.client.util.KubeConfig;
import java.io.FileReader;
import java.io.IOException;
/**
* A simple example of how to use the Java API from an application outside a kubernetes cluster
*
* <p>Easiest way to run this: mvn exec:java
* -Dexec.mainClass="io.kubernetes.client.examples.KubeConfigFileClientExample"
*
*/
public class untitled4 {
public static void main(String[] args) throws IOException, ApiException {
// file path to your KubeConfig
String kubeConfigPath = "/home/robin/.kube/config";
// loading the out-of-cluster config, a kubeconfig from file-system
ApiClient client =
ClientBuilder.kubeconfig(KubeConfig.loadKubeConfig(new FileReader(kubeConfigPath))).build();
// set the global default api-client to the in-cluster one from above
Configuration.setDefaultApiClient(client);
// the CoreV1Api loads default api-client from global configuration.
CoreV1Api api = new CoreV1Api();
// invokes the CoreV1Api client
V1PodList list = api.listPodForAllNamespaces(null, null, null, null, null, null, null, null, null);
System.out.println("Listing all pods: ");
for (V1Pod item : list.getItems()) {
System.out.println(item.getMetadata().getName());
}
}
}
But I get this error:
Exception in thread "main" java.lang.IllegalStateException: Unimplemented
at io.kubernetes.client.util.authenticators.GCPAuthenticator.refresh(GCPAuthenticator.java:61)
at io.kubernetes.client.util.KubeConfig.getAccessToken(KubeConfig.java:215)
at io.kubernetes.client.util.credentials.KubeconfigAuthentication.<init>(KubeconfigAuthentication.java:46)
at io.kubernetes.client.util.ClientBuilder.kubeconfig(ClientBuilder.java:276)
at untitled4.main(untitled4.java:28)
Process finished with exit code 1

There is an open issue on GitHub related with this problem. For now you can use workarounds like the one, proposed by jhbae200 in this comment:
I am using it like this.
package kubernetes.gcp;
import com.google.auth.oauth2.AccessToken;
import com.google.auth.oauth2.GoogleCredentials;
import io.kubernetes.client.util.KubeConfig;
import io.kubernetes.client.util.authenticators.Authenticator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.time.Instant;
import java.util.Date;
import java.util.Map;
public class ReplacedGCPAuthenticator implements Authenticator {
private static final Logger log;
private static final String ACCESS_TOKEN = "access-token";
private static final String EXPIRY = "expiry";
static {
log = LoggerFactory.getLogger(io.kubernetes.client.util.authenticators.GCPAuthenticator.class);
}
private final GoogleCredentials credentials;
public ReplacedGCPAuthenticator(GoogleCredentials credentials) {
this.credentials = credentials;
}
public String getName() {
return "gcp";
}
public String getToken(Map<String, Object> config) {
return (String) config.get("access-token");
}
public boolean isExpired(Map<String, Object> config) {
Object expiryObj = config.get("expiry");
Instant expiry = null;
if (expiryObj instanceof Date) {
expiry = ((Date) expiryObj).toInstant();
} else if (expiryObj instanceof Instant) {
expiry = (Instant) expiryObj;
} else {
if (!(expiryObj instanceof String)) {
throw new RuntimeException("Unexpected object type: " + expiryObj.getClass());
}
expiry = Instant.parse((String) expiryObj);
}
return expiry != null && expiry.compareTo(Instant.now()) <= 0;
}
public Map<String, Object> refresh(Map<String, Object> config) {
try {
AccessToken accessToken = this.credentials.refreshAccessToken();
config.put(ACCESS_TOKEN, accessToken.getTokenValue());
config.put(EXPIRY, accessToken.getExpirationTime());
} catch (IOException e) {
throw new RuntimeException(e);
}
return config;
}
}
Running in.
//GoogleCredentials.fromStream(--something credential.json filestream--)
KubeConfig.registerAuthenticator(new ReplacedGCPAuthenticator(GoogleCredentials.getApplicationDefault()));
ApiClient client = Config.defaultClient();
Configuration.setDefaultApiClient(client);
CoreV1Api api = new CoreV1Api();
V1PodList list = api.listNamespacedPod("default", null, null, null, null, null, null, null, 30, Boolean.FALSE);
for (V1Pod item : list.getItems()) {
System.out.println(item.getMetadata().getName());
}

How to add "text/plain" MIME type to DataHandler

I have been struggling with getting this test to work for awhile, the relevant code executes fine in production my assumption is that it has some additional configuration, lots of searching seems to be related specifically to email handling and additional libraries, I don't want to include anything else, what am I missing to link DataHandler to a relevant way of handling "text/plain" ?
Expected result: DataHandler allows me to stream the input "Value" back into a result.
Reproduce issue with this code:
import java.io.IOException;
import java.io.InputStream;
import javax.activation.CommandInfo;
import javax.activation.CommandMap;
import javax.activation.DataHandler;
import org.apache.commons.io.IOUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
public class DataHandlerTest {
#Before
public void setUp() throws Exception {
}
#After
public void tearDown() throws Exception {
}
#Test
public void test() throws IOException {
printDefaultCommandMap();
DataHandler dh = new DataHandler("Value", "text/plain");
System.out.println("DataHandler commands:");
printDataHandlerCommands(dh);
dh.setCommandMap(CommandMap.getDefaultCommandMap());
System.out.println("DataHandler commands:");
printDataHandlerCommands(dh);
final InputStream in = dh.getInputStream();
String result = new String(IOUtils.toByteArray(in));
System.out.println("Returned String: " + result);
}
private void printDataHandlerCommands(DataHandler dh) {
CommandInfo[] infos = dh.getAllCommands();
printCommands(infos);
}
private void printDefaultCommandMap() {
CommandMap currentMap = CommandMap.getDefaultCommandMap();
String[] mimeTypes = currentMap.getMimeTypes();
System.out.println("Found " + mimeTypes.length + " MIME types.");
for (String mimeType : mimeTypes) {
System.out.println("Commands for: " + mimeType);
printCommands(currentMap.getAllCommands(mimeType));
}
}
private void printCommands(CommandInfo[] infos) {
for (CommandInfo info : infos) {
System.out.println(" Command Class: " +info.getCommandClass());
System.out.println(" Command Name: " + info.getCommandName());
}
}
}
Exception:
javax.activation.UnsupportedDataTypeException: no object DCH for MIME
type text/plain at
javax.activation.DataHandler.getInputStream(DataHandler.java:249)
Help much appreciated, I hope this is a well formed question!
========================
Update 25th February
I have found if i know I stored a String in DataHandler, then I can cast the result to String and return the object that was stored, example:
#Test
public void testGetWithoutStream() throws IOException {
String inputString = "Value";
DataHandler dh = new DataHandler(inputString, "text/plain");
String rawResult = (String) dh.getContent();
assertEquals(inputString, rawResult);
}
But the code under test uses an InputStream, so my 'real' tests still fail when executed locally.
Continuing my investigation and still hoping for someone's assistance/guidance on this one...

Answering my own question for anyone's future reference.
All credit goes to: https://community.oracle.com/thread/1675030?start=0
The principle here is that you need to provide DataHandler a factory that contains a DataContentHandler that will behave as you would like it to for your MIME type, setting this is via a static method that seems to affect all DataHandler instances.
I declared a new class (SystemDataHandlerConfigurator), which has a single public method that creates my factory and provides it the static DataHandler.setDataContentHandlerFactory() function.
My tests now work correctly if I do this before they run:
SystemDataHandlerConfigurator configurator = new SystemDataHandlerConfigurator();
configurator.setupCustomDataContentHandlers();
SystemDataHandlerConfigurator
import java.io.IOException;
import javax.activation.*;
public class SystemDataHandlerConfigurator {
public void setupCustomDataContentHandlers() {
DataHandler.setDataContentHandlerFactory(new CustomDCHFactory());
}
private class CustomDCHFactory implements DataContentHandlerFactory {
#Override
public DataContentHandler createDataContentHandler(String mimeType) {
return new BinaryDataHandler();
}
}
private class BinaryDataHandler implements DataContentHandler {
/** Creates a new instance of BinaryDataHandler */
public BinaryDataHandler() {
}
/** This is the key, it just returns the data uninterpreted. */
public Object getContent(javax.activation.DataSource dataSource) throws java.io.IOException {
return dataSource.getInputStream();
}
public Object getTransferData(java.awt.datatransfer.DataFlavor dataFlavor,
javax.activation.DataSource dataSource)
throws java.awt.datatransfer.UnsupportedFlavorException,
java.io.IOException {
return null;
}
public java.awt.datatransfer.DataFlavor[] getTransferDataFlavors() {
return new java.awt.datatransfer.DataFlavor[0];
}
public void writeTo(Object obj, String mimeType, java.io.OutputStream outputStream)
throws java.io.IOException {
if (mimeType == "text/plain") {
byte[] stringByte = (byte[]) ((String) obj).getBytes("UTF-8");
outputStream.write(stringByte);
}
else {
throw new IOException("Unsupported Data Type: " + mimeType);
}
}
}
}

Apache flink pattern conditions with list

I wrote a pattern. I have a list for conditions(gettin rules from json).Data(json) is coming form kafka server . I want to filter the data with this list. But it is not working. How can I do that?
I am not sure about keyedstream and alarms in for. Can flink work like this?
main program:
package cep_kafka_eample.cep_kafka;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonParser;
import org.apache.flink.cep.CEP;
import org.apache.flink.cep.PatternSelectFunction;
import org.apache.flink.cep.PatternStream;
import org.apache.flink.cep.pattern.Pattern;
import org.apache.flink.streaming.api.TimeCharacteristic;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.windowing.assigners.SlidingProcessingTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer010;
import org.apache.flink.streaming.util.serialization.JSONDeserializationSchema;
import util.AlarmPatterns;
import util.Rules;
import util.TypeProperties;
import java.io.FileReader;
import java.util.*;
public class MainClass {
public static void main( String[] args ) throws Exception
{
ObjectMapper mapper = new ObjectMapper();
JsonParser parser = new JsonParser();
Object obj = parser.parse(new FileReader(
"c://new 5.json"));
JsonArray array = (JsonArray)obj;
Gson googleJson = new Gson();
List<Rules> ruleList = new ArrayList<>();
for(int i = 0; i< array.size() ; i++) {
Rules jsonObjList = googleJson.fromJson(array.get(i), Rules.class);
ruleList.add(jsonObjList);
}
//apache kafka properties
Properties properties = new Properties();
properties.setProperty("zookeeper.connect", "localhost:2181");
properties.setProperty("bootstrap.servers", "localhost:9092");
//starting flink
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.enableCheckpointing(1000).setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
//get kafka values
FlinkKafkaConsumer010<ObjectNode> myConsumer = new FlinkKafkaConsumer010<>("demo", new JSONDeserializationSchema(),
properties);
List<Pattern<ObjectNode,?>> patternList = new ArrayList<>();
DataStream<ObjectNode> dataStream = env.addSource(myConsumer);
dataStream.windowAll(SlidingProcessingTimeWindows.of(Time.seconds(10), Time.seconds(5)));
DataStream<ObjectNode> keyedStream = dataStream;
//get pattern list, keyeddatastream
for(Rules rules : ruleList){
List<TypeProperties> typePropertiesList = rules.getTypePropList();
for (int i = 0; i < typePropertiesList.size(); i++) {
TypeProperties typeProperty = typePropertiesList.get(i);
if (typeProperty.getGroupType() != null && typeProperty.getGroupType().equals("group")) {
keyedStream = keyedStream.keyBy(
jsonNode -> jsonNode.get(typeProperty.getPropName().toString())
);
}
}
Pattern<ObjectNode,?> pattern = new AlarmPatterns().getAlarmPattern(rules);
patternList.add(pattern);
}
//CEP pattern and alarms
List<DataStream<Alert>> alertList = new ArrayList<>();
for(Pattern<ObjectNode,?> pattern : patternList){
PatternStream<ObjectNode> patternStream = CEP.pattern(keyedStream, pattern);
DataStream<Alert> alarms = patternStream.select(new PatternSelectFunction<ObjectNode, Alert>() {
private static final long serialVersionUID = 1L;
public Alert select(Map<String, List<ObjectNode>> map) throws Exception {
return new Alert("new message");
}
});
alertList.add(alarms);
}
env.execute("Flink CEP monitoring job");
}
}
getAlarmPattern:
package util;
import org.apache.flink.cep.pattern.Pattern;
import org.apache.flink.cep.pattern.conditions.IterativeCondition;
import org.apache.flink.streaming.api.datastream.DataStream;
import com.fasterxml.jackson.databind.node.ObjectNode;
public class AlarmPatterns {
public Pattern<ObjectNode, ?> getAlarmPattern(Rules rules) {
//MySimpleConditions conditions = new MySimpleConditions();
Pattern<ObjectNode, ?> alarmPattern = Pattern.<ObjectNode>begin("first")
.where(new IterativeCondition<ObjectNode>() {
#Override
public boolean filter(ObjectNode jsonNodes, Context<ObjectNode> context) throws Exception {
for (Criterias criterias : rules.getCriteriaList()) {
if (criterias.getCriteriaType().equals("equals")) {
return jsonNodes.get(criterias.getPropName()).equals(criterias.getCriteriaValue());
} else if (criterias.getCriteriaType().equals("greaterThen")) {
if (!jsonNodes.get(criterias.getPropName()).equals(criterias.getCriteriaValue())) {
return false;
}
int count = 0;
for (ObjectNode node : context.getEventsForPattern("first")) {
count += node.get("value").asInt();
}
return Integer.compare(count, 5) > 0;
} else if (criterias.getCriteriaType().equals("lessThen")) {
if (!jsonNodes.get(criterias.getPropName()).equals(criterias.getCriteriaValue())) {
return false;
}
int count = 0;
for (ObjectNode node : context.getEventsForPattern("first")) {
count += node.get("value").asInt();
}
return Integer.compare(count, 5) < 0;
}
}
return false;
}
}).times(rules.getRuleCount());
return alarmPattern;
}
}

Thanks for using FlinkCEP!
Could you provide some more details about what exactly is the error message (if any)? This will help a lot at pinning down the problem.
From a first look at the code, I can make the following observations:
At first, the line:
dataStream.windowAll(SlidingProcessingTimeWindows.of(Time.seconds(10), Time.seconds(5)));
will never be executed, as you never use this stream in the rest of your program.
Second, you should specify a sink to be taken after the select(), e.g. print() method on each of your PatternStreams. If you do not do so, then your output gets discarded. You can have a look here for examples, although the list is far from exhaustive.
Finally, I would recommend adding a within() clause to your pattern, so that you do not run out of memory.

Error was from my json object. I will fix it. When i am run job on intellij cep doesn't work. When submit from flink console it works.

How to call Fedora Commons findObjects method (web service)

I'm trying to make a search through the Fedora Commons web service. I'm interested in the findObjects method. How can I make a search in Java equal to the example described on the findObjects syntax documentation.
I'm particularly interested in this type of request:
http://localhost:8080/fedora/search?terms=fedora&pid=true&title=true
I'll attach some code, I have a class that can call my Fedora service already.
package test.fedora;
import info.fedora.definitions._1._0.types.DatastreamDef;
import info.fedora.definitions._1._0.types.MIMETypedStream;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.List;
import javax.xml.ws.BindingProvider;
import org.w3c.dom.Document;
public class FedoraAccessor {
info.fedora.definitions._1._0.api.FedoraAPIAService service;
info.fedora.definitions._1._0.api.FedoraAPIA port;
final String username = "xxxx";
final String password = "yyyy";
public FedoraAClient() {
service = new info.fedora.definitions._1._0.api.FedoraAPIAService();
port = service.getFedoraAPIAServiceHTTPPort();
((BindingProvider) port.getRequestContext().put(BindingProvider.USERNAME_PROPERTY, username);
((BindingProvider) port).getRequestContext().put(BindingProvider.PASSWORD_PROPERTY, password);
}
public List findObjects() {
//how?
}
public List<DatastreamDef> listDatastreams(String pid, String asOfTime) {
List<DatastreamDef> result = null;
try {
result = port.listDatastreams(pid, asOfTime);
} catch (Exception ex) {
ex.printStackTrace();
}
return result;
}
}

It's easier using the client from mediashelf (http://mediashelf.github.com/fedora-client/). Here's an example searching for objects containing the string foobar in the title:
#Test
public void doTest() throws FedoraClientException {
connect();
FindObjectsResponse response = null;
response = findObjects().pid().title().query("title~foobar").execute(fedoraClient);
List<String> pids = response.getPids();
List<String> titles = new ArrayList<String>();
for (String pid : pids) {
titles.add(response.getObjectField(pid, "title").get(0));
}
assertEquals(7, titles.size());
}

Getting started with SNMP4J

I need to make an agent in SNMP4J, but the documentation on how to get started is pretty poor. Does anyone have any experience with SNMP4J and could give me an idea on how to get started? Thanks.

You can download the source code for SNMP4JAgent here:
http://www.snmp4j.org/html/download.html
The source code includes a sample agent -- look in the org.snmp4j.agent.example package for all of the related classes.
http://www.snmp4j.org/agent/doc/org/snmp4j/agent/example/SampleAgent.html
One way of getting started would be to create an agent using the example code and then modify it to suit your needs. The JavaDoc describing each of the classes is a bit terse, but it's complete.

Good documentation of SNMPv3 implementation using SNMP4j libraries is really hard to find. There are no working examples of SNMPv3 agents in the official documentation. I wrote a basic SNMP Agent that can connect using SNMPv3 protocol, and perform GET and SET operations on the server.
import java.io.IOException;
import org.snmp4j.PDU;
import org.snmp4j.ScopedPDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.UserTarget;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.MPv3;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.security.AuthGeneric;
import org.snmp4j.security.AuthSHA;
import org.snmp4j.security.PrivAES128;
import org.snmp4j.security.PrivacyGeneric;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.security.UsmUser;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.TransportIpAddress;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultTcpTransportMapping;
import org.snmp4j.transport.DefaultUdpTransportMapping;
public class SNMPV3Agent {
private Address nmsIP;
private String user;
private String securityName;
private String privacyPassword;
private String authorizationPassword;
private AuthGeneric authProtocol;
private PrivacyGeneric privacyProtocol;
private String protocol;
private long timeOut = 1000L;
private int noOfRetries = 2;
private Snmp snmp;
private UserTarget target;
SNMPV3Agent(String ip, String protocol, int snmpPort, String username,
String securityName, String privacyPassword, String authPassowrd,
AuthGeneric authProtocol, PrivacyGeneric privacyProtocol) {
nmsIP = GenericAddress.parse(protocol + ":" + ip + "/" + snmpPort);
System.out.println("NMS IP set : " + nmsIP.toString());
this.protocol = protocol;
this.user = username;
this.securityName = securityName;
this.privacyPassword = privacyPassword;
this.authorizationPassword = authPassowrd;
this.authProtocol = authProtocol;
this.privacyProtocol = privacyProtocol;
}
public static void main(String[] args) {
SNMPV3Agent agent = new SNMPV3Agent("nms/server-ip", "udp", 162,
"abhinav", "abhinav", "myprivpass", "myauthpass",
new AuthSHA(), new PrivAES128());
try {
agent.startAgent();
ResponseEvent response = agent
.snmpGetOperation(SnmpConstants.sysName);
System.out.println(response.getResponse());
// Similarly you can perform set operation.
} catch (IOException e) {
e.printStackTrace();
}
}
public void startAgent() throws IOException {
if (snmp == null) {
TransportMapping<? extends TransportIpAddress> transport = null;
if (protocol.equalsIgnoreCase("udp")) {
System.out.println("UDP Protocol selected.");
transport = new DefaultUdpTransportMapping();
} else {
System.out.println("TCP Protocol selected.");
transport = new DefaultTcpTransportMapping();
}
snmp = new Snmp(transport);
USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(
MPv3.createLocalEngineID()), 0);
SecurityModels.getInstance().addSecurityModel(usm);
transport.listen();
snmp.getUSM().addUser(
new OctetString(user),
new UsmUser(new OctetString(securityName), authProtocol
.getID(), new OctetString(authorizationPassword),
privacyProtocol.getID(), new OctetString(
privacyPassword)));
target = createUserTarget();
}
}
public ResponseEvent snmpSetOperation(VariableBinding[] vars)
throws IOException {
PDU setPdu = new ScopedPDU();
for (VariableBinding variableBinding : vars) {
setPdu.add(variableBinding);
}
return snmp.send(setPdu, target);
}
public ResponseEvent snmpGetOperation(OID oid) throws IOException {
PDU getPdu = new ScopedPDU();
getPdu.add(new VariableBinding(oid));
return snmp.get(getPdu, target);
}
private UserTarget createUserTarget() {
UserTarget target = new UserTarget();
target.setAddress(nmsIP);
target.setRetries(noOfRetries);
target.setTimeout(timeOut);
target.setVersion(3);
target.setSecurityLevel(3);
target.setSecurityName(new OctetString(securityName));
return target;
}
public long getTimeOut() {
return timeOut;
}
public void setTimeOut(long timeOut) {
this.timeOut = timeOut;
}
public int getNoOfRetries() {
return noOfRetries;
}
public void setNoOfRetries(int noOfRetries) {
this.noOfRetries = noOfRetries;
}
}
Adding other operations such as GETBulk will be relatively easy once you understand how GET and SET works. Let me know if you need more clarifications in the comments.

Here is a great link that describes the snmp class which is the core of snmp4j
http://www.snmp4j.org/doc/org/snmp4j/package-summary.html
Also take a look at the SnmpRequest.java for a quick example