move backend to kafka-ui repo

.gitignore

@@ -1,25 +1,31 @@
-# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**
+!**/src/test/**
 
-# dependencies
-node_modules
-.pnp
-.pnp.js
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
 
-# testing
-coverage
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
 
-# production
-build
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
 
-# misc
-.DS_Store
-.env.local
-.env.development.local
-.env.test.local
-.env.production.local
-
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
-
-.idea
+### VS Code ###
+.vscode/

.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

docker/kafka-second.yaml

@@ -0,0 +1,27 @@
+---
+version: '2'
+services:
+  zookeeperSecond:
+    image: confluentinc/cp-zookeeper:5.1.0
+    environment:
+      ZOOKEEPER_CLIENT_PORT: 2181
+      ZOOKEEPER_TICK_TIME: 2000
+    ports:
+      - 2182:2181
+
+  kafkaSecond:
+    image: confluentinc/cp-kafka:5.1.0
+    depends_on:
+      - zookeeperSecond
+    ports:
+      - 9093:9092
+      - 9998:9998
+    environment:
+      KAFKA_BROKER_ID: 1
+      KAFKA_ZOOKEEPER_CONNECT: zookeeperSecond:2181
+      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafkaSecond:29092,PLAINTEXT_HOST://localhost:9092
+      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
+      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
+      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
+      JMX_PORT: 9998
+      KAFKA_JMX_OPTS: -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=127.0.0.1 -Dcom.sun.management.jmxremote.rmi.port=9998

docker/kafka.yaml

@@ -0,0 +1,27 @@
+---
+version: '2'
+services:
+  zookeeper:
+    image: confluentinc/cp-zookeeper:5.1.0
+    environment:
+      ZOOKEEPER_CLIENT_PORT: 2181
+      ZOOKEEPER_TICK_TIME: 2000
+    ports:
+      - 2181:2181
+
+  kafka:
+    image: confluentinc/cp-kafka:5.1.0
+    depends_on:
+      - zookeeper
+    ports:
+      - 9092:9092
+      - 9997:9997
+    environment:
+      KAFKA_BROKER_ID: 1
+      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
+      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:29092,PLAINTEXT_HOST://localhost:9092
+      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
+      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
+      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
+      JMX_PORT: 9997
+      KAFKA_JMX_OPTS: -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=127.0.0.1 -Dcom.sun.management.jmxremote.rmi.port=9997

kafka-ui-api/pom.xml

@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>kafka-ui</artifactId>
+        <groupId>com.provectus</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>kafka-ui-api</artifactId>
+
+    <properties>
+        <org.mapstruct.version>1.3.1.Final</org.mapstruct.version>
+        <org.projectlombok.version>1.18.10</org.projectlombok.version>
+        <java.version>13</java.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>2.2.4.RELEASE</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-logging</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>com.provectus</groupId>
+            <artifactId>kafka-ui-contract</artifactId>
+            <version>0.0.1-SNAPSHOT</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.kafka</groupId>
+            <artifactId>kafka-clients</artifactId>
+            <version>2.4.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.101tec</groupId>
+            <artifactId>zkclient</artifactId>
+            <version>0.2</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mapstruct</groupId>
+            <artifactId>mapstruct</artifactId>
+            <version>${org.mapstruct.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-log4j2</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.5.1</version>
+                <configuration>
+                    <source>13</source>
+                    <target>13</target>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.mapstruct</groupId>
+                            <artifactId>mapstruct-processor</artifactId>
+                            <version>${org.mapstruct.version}</version>
+                        </path>
+                        <path>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                            <version>${org.projectlombok.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

kafka-ui-api/src/main/java/com/provectus/kafka/ui/KafkaMetricsApplication.java

@@ -0,0 +1,15 @@
+package com.provectus.kafka.ui;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@SpringBootApplication
+@EnableScheduling
+public class KafkaMetricsApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(KafkaMetricsApplication.class, args);
+	}
+
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/ClustersMetricUpdateScheduler.java

@@ -0,0 +1,36 @@
+package com.provectus.kafka.ui.cluster;
+
+import com.provectus.kafka.ui.cluster.model.KafkaCluster;
+import com.provectus.kafka.ui.cluster.service.ClusterService;
+import com.provectus.kafka.ui.jmx.JmxService;
+import com.provectus.kafka.ui.kafka.KafkaService;
+import com.provectus.kafka.ui.model.ClusterStatus;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+@Log4j2
+public class ClustersMetricUpdateScheduler {
+
+    private final JmxService jmxService;
+    private final KafkaService kafkaService;
+
+    private final ClusterService clusterService;
+
+    @Scheduled(fixedRate = 30000)
+    public void updateMetrics() {
+        for (KafkaCluster cluster : clusterService.getKafkaClusters()) {
+            try {
+                kafkaService.loadClusterMetrics(cluster);
+                jmxService.loadClusterMetrics(cluster);
+                cluster.setStatus(ClusterStatus.ONLINE);
+            } catch (Exception e) {
+                log.error(e);
+                cluster.setStatus(ClusterStatus.OFFLINE);
+            }
+        }
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/config/ClustersProperties.java

@@ -0,0 +1,26 @@
+package com.provectus.kafka.ui.cluster.config;
+
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Configuration
+@ConfigurationProperties("kafka")
+@Data
+public class ClustersProperties {
+
+    List<Cluster> clusters = new ArrayList<>();
+
+    @Data
+    public static class Cluster {
+        String id;
+        String name;
+        String bootstrapServers;
+        String jmxHost;
+        String jmxPort;
+        String zookeeper;
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/mapper/ClusterMapper.java

@@ -0,0 +1,23 @@
+package com.provectus.kafka.ui.cluster.mapper;
+
+import com.provectus.kafka.ui.cluster.config.ClustersProperties;
+import com.provectus.kafka.ui.cluster.model.KafkaCluster;
+import com.provectus.kafka.ui.model.Cluster;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+
+@Mapper
+public interface ClusterMapper {
+
+    @Mapping(target = "brokerCount", ignore = true)
+    @Mapping(target = "bytesInPerSec", ignore = true)
+    @Mapping(target = "bytesOutPerSec", ignore = true)
+    @Mapping(target = "defaultCluster", ignore = true)
+    @Mapping(target = "onlinePartitionCount", ignore = true)
+    @Mapping(target = "topicCount", ignore = true)
+    Cluster toOpenApiCluster(KafkaCluster kafkaCluster);
+
+    @Mapping(target = "metricsMap", ignore = true)
+    @Mapping(target = "status", ignore = true)
+    KafkaCluster toKafkaCluster(ClustersProperties.Cluster clusterProperties);
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/model/KafkaCluster.java

@@ -0,0 +1,39 @@
+package com.provectus.kafka.ui.cluster.model;
+
+import com.provectus.kafka.ui.model.ClusterStatus;
+import lombok.AccessLevel;
+import lombok.Data;
+import lombok.experimental.FieldDefaults;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+
+@Data
+@FieldDefaults(level = AccessLevel.PRIVATE)
+public class KafkaCluster {
+
+    String id;
+    String name;
+    String jmxHost;
+    String jmxPort;
+    String bootstrapServers;
+    String zookeeper;
+    ClusterStatus status = ClusterStatus.OFFLINE;
+
+    Map<String, String> metricsMap = new ConcurrentHashMap<>();
+
+    public void putMetric(String metricKey, String metricValue) {
+        metricsMap.put(metricKey, metricValue);
+    }
+
+    public String getMetric(String metricKey) {
+        return metricsMap.get(metricKey);
+    }
+
+    public String getMetricsMapAsString() {
+        return metricsMap.keySet().stream()
+                .map(key -> key + "=" + metricsMap.get(key))
+                .collect(Collectors.joining(", ", "{", "}"));
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/model/MetricsConstants.java

@@ -0,0 +1,12 @@
+package com.provectus.kafka.ui.cluster.model;
+
+public final class MetricsConstants {
+
+    private MetricsConstants() {}
+
+    public static final String BYTES_IN_PER_SEC = "BytesInPerSec";
+    public static final String BYTES_OUT_PER_SEC = "BytesOutPerSec";
+    public static final String BROKERS_COUNT = "BrokersCount";
+    public static final String TOPIC_COUNT = "TopicCount";
+    public static final String PARTITIONS_COUNT = "PartitionsCount";
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/service/ClusterService.java

@@ -0,0 +1,67 @@
+package com.provectus.kafka.ui.cluster.service;
+
+import com.provectus.kafka.ui.cluster.config.ClustersProperties;
+import com.provectus.kafka.ui.cluster.mapper.ClusterMapper;
+import com.provectus.kafka.ui.cluster.model.KafkaCluster;
+import com.provectus.kafka.ui.cluster.model.MetricsConstants;
+import com.provectus.kafka.ui.model.Cluster;
+import lombok.RequiredArgsConstructor;
+import org.mapstruct.factory.Mappers;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import javax.annotation.PostConstruct;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+public class ClusterService {
+
+    private final List<KafkaCluster> kafkaClusters = new ArrayList<>();
+
+    private final ClustersProperties clusterProperties;
+
+    private final ClusterMapper clusterMapper = Mappers.getMapper(ClusterMapper.class);
+
+    @PostConstruct
+    public void init() {
+        for (ClustersProperties.Cluster clusterProperties : clusterProperties.getClusters()) {
+            kafkaClusters.add(clusterMapper.toKafkaCluster(clusterProperties));
+        }
+    }
+
+    public Mono<ResponseEntity<Flux<Cluster>>> getClusters() {
+        List<Cluster> clusters = kafkaClusters
+                .stream()
+                .map(kafkaCluster -> {
+                    Cluster cluster = clusterMapper.toOpenApiCluster(kafkaCluster);
+                    cluster.setBrokerCount(intValueOfOrNull(kafkaCluster.getMetric(MetricsConstants.BROKERS_COUNT)));
+                    cluster.setTopicCount(intValueOfOrNull(kafkaCluster.getMetric(MetricsConstants.TOPIC_COUNT)));
+                    cluster.setBytesInPerSec(intValueOfOrNull(kafkaCluster.getMetric(MetricsConstants.BYTES_IN_PER_SEC)));
+                    cluster.setBytesOutPerSec(intValueOfOrNull(kafkaCluster.getMetric(MetricsConstants.BYTES_OUT_PER_SEC)));
+                    cluster.setOnlinePartitionCount(intValueOfOrNull(kafkaCluster.getMetric(MetricsConstants.PARTITIONS_COUNT)));
+                    return cluster;
+                })
+                .collect(Collectors.toList());
+
+        return Mono.just(ResponseEntity.ok(Flux.fromIterable(clusters)));
+    }
+
+    public List<KafkaCluster> getKafkaClusters() {
+        return kafkaClusters;
+    }
+
+    private Integer intValueOfOrNull(String s) {
+        try {
+            return Integer.valueOf(s);
+        } catch (NumberFormatException e) {
+            return null;
+        }
+    }
+
+
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/jmx/JmxConstants.java

@@ -0,0 +1,18 @@
+package com.provectus.kafka.ui.jmx;
+
+import com.provectus.kafka.ui.cluster.model.MetricsConstants;
+
+import java.util.Map;
+
+import static java.util.Map.entry;
+
+public final class JmxConstants {
+
+    private JmxConstants() {}
+
+    public static final Map<MBeanInfo, String> mbeanToAttributeMap = Map.ofEntries(
+            entry(MBeanInfo.of("kafka.server:type=BrokerTopicMetrics,name=BytesInPerSec", "Count"), MetricsConstants.BYTES_IN_PER_SEC),
+            entry(MBeanInfo.of("kafka.server:type=BrokerTopicMetrics,name=BytesOutPerSec", "Count"), MetricsConstants.BYTES_OUT_PER_SEC)
+    );
+
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/jmx/JmxService.java

@@ -0,0 +1,34 @@
+package com.provectus.kafka.ui.jmx;
+
+import com.provectus.kafka.ui.cluster.model.KafkaCluster;
+import lombok.RequiredArgsConstructor;
+import lombok.SneakyThrows;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.stereotype.Service;
+
+import javax.management.MBeanServerConnection;
+import javax.management.ObjectName;
+import javax.management.remote.JMXConnector;
+import javax.management.remote.JMXConnectorFactory;
+import javax.management.remote.JMXServiceURL;
+import java.util.Map;
+
+@Service
+@Log4j2
+@RequiredArgsConstructor
+public class JmxService {
+
+    @SneakyThrows
+    public void loadClusterMetrics(KafkaCluster kafkaCluster) {
+        String url = "service:jmx:rmi:///jndi/rmi://" + kafkaCluster.getJmxHost() + ":" + kafkaCluster.getJmxPort() + "/jmxrmi";
+        JMXServiceURL serviceUrl = new JMXServiceURL(url);
+        try (JMXConnector jmxConnector = JMXConnectorFactory.connect(serviceUrl, null)) {
+            MBeanServerConnection connection = jmxConnector.getMBeanServerConnection();
+            for (Map.Entry<MBeanInfo, String> mbeanToMetric : JmxConstants.mbeanToAttributeMap.entrySet()) {
+                MBeanInfo mBeanInfo = mbeanToMetric.getKey();
+                Object attributeValue = connection.getAttribute(new ObjectName(mBeanInfo.getName()), mBeanInfo.getAttribute());
+                kafkaCluster.putMetric(mbeanToMetric.getValue(), attributeValue.toString());
+            }
+        }
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/jmx/MBeanInfo.java

@@ -0,0 +1,24 @@
+package com.provectus.kafka.ui.jmx;
+
+public class MBeanInfo {
+
+    private String name;
+    private String attribute;
+
+    private MBeanInfo(String name, String attribute) {
+        this.name = name;
+        this.attribute = attribute;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getAttribute() {
+        return attribute;
+    }
+
+    public static MBeanInfo of(String name, String attribute) {
+        return new MBeanInfo(name, attribute);
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/kafka/KafkaService.java

@@ -0,0 +1,49 @@
+package com.provectus.kafka.ui.kafka;
+
+import com.provectus.kafka.ui.cluster.model.MetricsConstants;
+import com.provectus.kafka.ui.cluster.model.KafkaCluster;
+import lombok.RequiredArgsConstructor;
+import lombok.SneakyThrows;
+import org.I0Itec.zkclient.ZkClient;
+import org.apache.kafka.clients.admin.*;
+import org.springframework.stereotype.Service;
+
+import java.util.Properties;
+import java.util.Set;
+
+@Service
+@RequiredArgsConstructor
+public class KafkaService {
+
+    @SneakyThrows
+    public void loadClusterMetrics(KafkaCluster kafkaCluster) {
+        isZookeeperRunning(kafkaCluster);
+
+        Properties properties = new Properties();
+        properties.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaCluster.getBootstrapServers());
+        properties.put(AdminClientConfig.REQUEST_TIMEOUT_MS_CONFIG, 5000);
+        AdminClient adminClient = AdminClient.create(properties);
+
+        kafkaCluster.putMetric(MetricsConstants.BROKERS_COUNT, String.valueOf(adminClient.describeCluster().nodes().get().size()));
+
+        ListTopicsOptions listTopicsOptions = new ListTopicsOptions();
+        listTopicsOptions.listInternal(false);
+        Set<String> topicNames = adminClient.listTopics(listTopicsOptions).names().get();
+        kafkaCluster.putMetric(MetricsConstants.TOPIC_COUNT, String.valueOf(topicNames.size()));
+
+        int partitionsNum = 0;
+        DescribeTopicsResult describeTopicsResult = adminClient.describeTopics(topicNames);
+        for (TopicDescription topicDescription : describeTopicsResult.all().get().values()) {
+            partitionsNum += topicDescription.partitions().size();
+        }
+        kafkaCluster.putMetric(MetricsConstants.PARTITIONS_COUNT, String.valueOf(partitionsNum));
+
+    }
+
+    public static void isZookeeperRunning(KafkaCluster kafkaCluster){
+        //Because kafka connector waits for 2 minutes with retries before telling that there is no connection
+        //ZKClient is used to not wait 2 minutes for response. If there is no connection, exception will be thrown
+        ZkClient zkClient = new ZkClient(kafkaCluster.getZookeeper(), 1000);
+        zkClient.close();
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/rest/MetricsRestController.java

@@ -0,0 +1,55 @@
+package com.provectus.kafka.ui.rest;
+
+import com.provectus.kafka.ui.api.ClustersApi;
+import com.provectus.kafka.ui.cluster.service.ClusterService;
+import com.provectus.kafka.ui.model.Cluster;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.server.ServerWebExchange;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/clusters")
+public class MetricsRestController implements ClustersApi {
+
+    private final ClusterService clusterService;
+
+    @GetMapping("/{clusterId}/brokers")
+    public void getBrokers(@PathVariable("clusterId") String clusterId) {
+
+    }
+
+    @GetMapping("/{clusterId}/metrics/broker")
+    public void getBrokerMetrics(@PathVariable("clusterId") String clusterId) {
+
+    }
+
+    @GetMapping("/{clusterId}/topics")
+    public void getTopics(@PathVariable("clusterId") String clusterId) {
+
+    }
+
+    @GetMapping("/{clusterId}/topics/{topicId}")
+    public void getTopic(@PathVariable("clusterId") String clusterId,
+                         @PathVariable("topicId") String topicId) {
+    }
+
+    @PostMapping("/{clusterId}/topics")
+    public void createTopic(@PathVariable("clusterId") String clusterId) {
+
+    }
+
+    @PutMapping("/{clusterId}/topics/{topicId}")
+    public void putTopic(@PathVariable("clusterId") String clusterId,
+                         @PathVariable("topicId") String topicId) {
+    }
+
+    @Override
+    @GetMapping
+    public Mono<ResponseEntity<Flux<Cluster>>> getClusters(ServerWebExchange exchange) {
+        return clusterService.getClusters();
+    }
+}

kafka-ui-api/src/main/java/com/provectus/kafka/ui/rest/config/CorsGlobalConfiguration.java

@@ -0,0 +1,20 @@
+package com.provectus.kafka.ui.rest.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.config.CorsRegistry;
+import org.springframework.web.reactive.config.EnableWebFlux;
+import org.springframework.web.reactive.config.WebFluxConfigurer;
+
+@Configuration
+@EnableWebFlux
+public class CorsGlobalConfiguration implements WebFluxConfigurer {
+
+    @Override
+    public void addCorsMappings(CorsRegistry registry) {
+        registry.addMapping("/**")
+                .allowedOrigins("*")
+                .allowedMethods("*")
+                .allowedHeaders("*")
+                .allowCredentials(true);
+    }
+}

kafka-ui-api/src/main/resources/application.yml

@@ -0,0 +1,16 @@
+kafka:
+  clusters:
+    -
+      id: wrYGf-csNgiGdK7B_ADF7Z
+      name: local
+      bootstrapServers: localhost:9092
+      jmxHost: localhost
+      jmxPort: 9997
+      zookeeper: localhost:2181
+    -
+      id: dMMQx-WRh77BKYas_g2ZTz
+      name: secondLocal
+      bootstrapServers: localhost:9093
+      jmxHost: localhost
+      jmxPort: 9998
+      zookeeper: localhost:2182

kafka-ui-api/src/main/resources/log4j2.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="ERROR">
+    <Appenders>
+        <Console name="Console" target="SYSTEM_OUT">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </Console>
+    </Appenders>
+    <Loggers>
+        <Logger name="com.provectus" level="debug" additivity="false">
+            <AppenderRef ref="Console"/>
+        </Logger>
+        <Logger name="org.springframework.http.codec.json.Jackson2JsonDecoder" level="debug" additivity="false">
+            <AppenderRef ref="Console"/>
+        </Logger>
+        <Logger name="org.springframework.http.codec.json.Jackson2JsonEncoder" level="debug" additivity="false">
+            <AppenderRef ref="Console"/>
+        </Logger>
+
+        <logger name="reactor.netty.http.server.AccessLog" level="info" additivity="false">
+            <appender-ref ref="Console"/>
+        </logger>
+        <Root level="info">
+            <AppenderRef ref="Console"/>
+        </Root>
+    </Loggers>
+</Configuration>

kafka-ui-api/src/test/java/com/provectus/kafka/ui/KafkaMetricsApplicationTests.java

@@ -0,0 +1,12 @@
+package com.provectus.kafka.ui;
+
+import org.junit.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class KafkaMetricsApplicationTests {
+
+	@Test
+	public void contextLoads() {
+	}
+}

kafka-ui-contract/pom.xml

@@ -0,0 +1,180 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>kafka-ui</artifactId>
+        <groupId>com.provectus</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>kafka-ui-contract</artifactId>
+
+    <dependencies>
+        <!-- needed for running test in idea, without this fix, tests don't compile -->
+        <!-- https://mvnrepository.com/artifact/junit/junit -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13</version>
+            <scope>compile</scope>
+        </dependency>
+    </dependencies>
+
+
+    <properties>
+        <maven.compiler.source>13</maven.compiler.source>
+        <maven.compiler.target>13</maven.compiler.target>
+    </properties>
+
+    <profiles>
+
+        <!--        SPRING WebFlux API          -->
+        <profile>
+            <id>generate-spring-webflux-api</id>
+            <activation>
+                <activeByDefault>true</activeByDefault>
+            </activation>
+
+            <dependencies>
+                <dependency>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-webflux</artifactId>
+                    <version>2.2.1.RELEASE</version>
+                </dependency>
+
+                <dependency>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-validation</artifactId>
+                    <version>2.2.1.RELEASE</version>
+                </dependency>
+                <dependency>
+                    <groupId>org.openapitools</groupId>
+                    <artifactId>jackson-databind-nullable</artifactId>
+                    <version>0.2.0</version>
+                </dependency>
+                <dependency>
+                    <groupId>io.springfox</groupId>
+                    <artifactId>springfox-swagger2</artifactId>
+                    <version>2.9.2</version>
+                </dependency>
+
+                <dependency>
+                    <groupId>com.fasterxml.jackson.core</groupId>
+                    <artifactId>jackson-databind</artifactId>
+                    <version>2.10.0</version>
+                </dependency>
+                <dependency>
+                    <groupId>com.fasterxml.jackson.dataformat</groupId>
+                    <artifactId>jackson-dataformat-yaml</artifactId>
+                    <version>2.10.0</version>
+                </dependency>
+                <dependency>
+                    <groupId>com.fasterxml.jackson.datatype</groupId>
+                    <artifactId>jackson-datatype-jsr310</artifactId>
+                    <version>2.10.0</version>
+                </dependency>
+                <dependency>
+                    <groupId>org.openapitools</groupId>
+                    <artifactId>jackson-databind-nullable</artifactId>
+                    <version>0.2.1</version>
+                </dependency>
+                <dependency>
+                    <groupId>com.google.code.findbugs</groupId>
+                    <artifactId>jsr305</artifactId>
+                    <version>3.0.2</version>
+                </dependency>
+
+                <dependency>
+                    <groupId>com.google.code.gson</groupId>
+                    <artifactId>gson</artifactId>
+                    <version>2.8.5</version>
+                </dependency>
+                <!-- https://mvnrepository.com/artifact/io.rest-assured/rest-assured -->
+                <dependency>
+                    <groupId>io.rest-assured</groupId>
+                    <artifactId>rest-assured</artifactId>
+                    <version>4.1.2</version>
+                </dependency>
+                <!-- https://mvnrepository.com/artifact/io.gsonfire/gson-fire -->
+                <dependency>
+                    <groupId>io.gsonfire</groupId>
+                    <artifactId>gson-fire</artifactId>
+                    <version>1.8.3</version>
+                </dependency>
+                <!-- https://mvnrepository.com/artifact/com.squareup.okio/okio -->
+                <dependency>
+                    <groupId>com.squareup.okio</groupId>
+                    <artifactId>okio</artifactId>
+                    <version>2.4.3</version>
+                </dependency>
+            </dependencies>
+
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.openapitools</groupId>
+                        <artifactId>openapi-generator-maven-plugin</artifactId>
+                        <version>4.2.2</version>
+                        <executions>
+                            <execution>
+                                <id>generate-backend-api</id>
+                                <goals>
+                                    <goal>generate</goal>
+                                </goals>
+                                <configuration>
+                                    <inputSpec>${project.basedir}/src/main/resources/swagger/kafka-ui-api.yaml
+                                    </inputSpec>
+                                    <output>${project.build.directory}/generated-sources/api</output>
+                                    <generatorName>spring</generatorName>
+                                    <!--<configHelp>true</configHelp>-->
+
+                                    <configOptions>
+                                        <modelPackage>com.provectus.kafka.ui.model</modelPackage>
+                                        <apiPackage>com.provectus.kafka.ui.api</apiPackage>
+                                        <sourceFolder>kafka-ui-contract</sourceFolder>
+
+                                        <reactive>true</reactive>
+
+                                        <interfaceOnly>true</interfaceOnly>
+                                        <skipDefaultInterface>true</skipDefaultInterface>
+                                        <useBeanValidation>true</useBeanValidation>
+                                        <useTags>true</useTags>
+
+                                        <dateLibrary>java8</dateLibrary>
+                                    </configOptions>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>com.github.ngeor</groupId>
+                <artifactId>yak4j-json-yaml-converter-maven-plugin</artifactId>
+                <version>0.0.4</version>
+                <executions>
+                    <execution>
+                        <id>yaml2json</id>
+                        <goals>
+                            <goal>yaml2json</goal>
+                        </goals>
+                        <configuration>
+                            <sourceDirectory>src/main/resources/swagger</sourceDirectory>
+                            <includes>
+                                <include>*.yaml</include>
+                            </includes>
+                            <outputDirectory>target/generated-sources/swagger</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml

@@ -0,0 +1,70 @@
+openapi: 3.0.0
+info:
+  description: Api Documentation
+  version: 0.1.0
+  title: Api Documentation
+  termsOfService: urn:tos
+  contact: {}
+  license:
+    name: Apache 2.0
+    url: http://www.apache.org/licenses/LICENSE-2.0
+tags:
+  - name: /clusters
+servers:
+  - url: /localhost
+
+paths:
+  /clusters:
+    get:
+      tags:
+        - /clusters
+      summary: getClusters
+      operationId: getClusters
+      responses:
+        200:
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Cluster'
+        401:
+          description: Unauthorized
+        403:
+          description: Forbidden
+
+components:
+  schemas:
+
+    Cluster:
+      type: object
+      properties:
+        id:
+          type: string
+        name:
+          type: string
+        defaultCluster:
+          type: boolean
+        status:
+          $ref: '#/components/schemas/ClusterStatus'
+        brokerCount:
+          type: integer
+        onlinePartitionCount:
+          type: integer
+        topicCount:
+          type: integer
+        bytesInPerSec:
+          type: integer
+        bytesOutPerSec:
+          type: integer
+      required:
+        - id
+        - name
+        - status
+
+    ClusterStatus:
+      type: string
+      enum:
+        - online
+        - offline

mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

pom.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+    <packaging>pom</packaging>
+    <modules>
+        <module>kafka-ui-contract</module>
+		<module>kafka-ui-api</module>
+	</modules>
+
+	<groupId>com.provectus</groupId>
+	<artifactId>kafka-ui</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>kafka-ui</name>
+	<description>Kafka metrics for UI panel</description>
+</project>