Spring Cloud Eureka 服务注册与发现中心（一）

太过爱你忘了你带给我的痛 2022-06-05 09:12 240阅读 0赞

Spring Cloud 项目中的子项目，Eureka 一个注重于AP的服务注册与发现服务，对比Zookeeper的集群，注重高可用与分区容错性。

如图：

![Image 1][]![Image 1][]

*  Eureka-discovery 2个服务互为伙伴，增加高可用性；
 *  Business-Service 多个业务服务想discovery进行注册，互为伙伴的discovery 会自动同步节点下注册的服务；
 *  discovery-Client 像discovery注册的同时，获取注册服务列表，通过Ribbon进行自身软负载

相关代码：

1.总体父工程pom

<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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.test.cloud</groupId>
        <artifactId>test-cloud-parent</artifactId>
        <version>1.0.RELEASE</version>
        <packaging>pom</packaging>
    
        <name>test-cloud-parent</name>
        <url>http://maven.apache.org</url>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.6.RELEASE</version>
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Edgware.RC1</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
        <build>
            <pluginManagement>
                <plugins>
                    <plugin>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-maven-plugin</artifactId>
                    </plugin>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-surefire-plugin</artifactId>
                        <version>2.12.4</version>
                        <configuration>
                            <skipTests>true</skipTests>
                        </configuration>
                    </plugin>
                </plugins>
            </pluginManagement>
        </build>
    </project>

2.Eureka-discovery相关POM代码

<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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.test.cloud</groupId>
        <artifactId>test-cloud-discovery</artifactId>
        <version>1.0-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>test-cloud-discovery</name>
        <url>http://maven.apache.org</url>
        <parent>
            <groupId>com.test.cloud</groupId>
            <artifactId>test-cloud-parent</artifactId>
            <version>1.0.RELEASE</version>
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka-server</artifactId>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <executions>
                        <execution>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <mainClass>com.hytera.test.cloud.App</mainClass>
                        <fork>true</fork>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>

3.discovery的入口程序

package com.test.cloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    /**
     * Hello world!
     *
     * @author Administrator
     */
    @SpringBootApplication
    @EnableEurekaServer
    public class App 
    {
        public static void main( String[] args )
        {
            SpringApplication.run(App.class, args);
        }
    }

4.discovery相关配置application.yml

server:
      port: 9080
    eureka:
      client:
        g-zip-content: true
        service-url:
              defaultZone: http://IP:${server.port}/eureka/
        fetch-registry: false
        register-with-eureka: false
      server:
        enable-self-preservation: false
        eviction-interval-timer-in-ms: 1000
    spring:
      application:
        name: Eureka-discovery-0

这里为注册中心的一个节点，如需要配置伙伴，defaultZone请配置对端IP及端口，

fetch-registry: true

5.business-server pom

<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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.test.cloud</groupId>
        <artifactId>test-cloud-server</artifactId>
        <version>1.0-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>test-cloud-server</name>
        <url>http://maven.apache.org</url>
        <parent>
            <groupId>com.test.cloud</groupId>
            <artifactId>test-cloud-parent</artifactId>
            <version>1.0.RELEASE</version>
        </parent>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <executions>
                        <execution>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <mainClass>com.hytera.test.cloud.App</mainClass>
                        <fork>true</fork>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>

6.business-server 配置

server:
      port: 9070
    eureka:
      client:
        service-url:
              defaultZone: http://IP:${server.port}/eureka/
      instance:
        #instance-id: ${spring.application.name}:${server.port}
        instance-id: ${spring.cloud.client.ipAddress}:${server.port}
        prefer-ip-address: true
        lease-expiration-duration-in-seconds: 15
        lease-renewal-interval-in-seconds: 5
    spring:
      application:
        name: Eureka-Server

7.business-server 入口类

package com.test.cloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    /**
     * Hello world!
     *
     * @author Administrator
     */
    @SpringBootApplication
    @EnableDiscoveryClient
    public class App
    {
        public static void main( String[] args )
        {
            SpringApplication.run(App.class, args);
        }
    }

8.business-server 服务生产类

package com.test.cloud.controller;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cloud.client.ServiceInstance;
    import org.springframework.cloud.client.discovery.DiscoveryClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    
    /**
     *
     * @author Administrator
     * @date 2017/11/23
     */
    @RestController
    public class MessageController {
        private static final Logger LOGGER = LoggerFactory.getLogger(MessageController.class);
        @Autowired
        private DiscoveryClient client;
        @RequestMapping("/getMsgInfo")
        public String getMessageInfo(String strGuid, String strUserName){
            String strMsg = strGuid + strUserName;
            ServiceInstance instance = client.getLocalServiceInstance();
            LOGGER.info("uri={}，serviceId={}，strMsg={}", instance.getUri(), instance.getServiceId(), strMsg);
            return strMsg;
        }
    }

9.discovery-client pom

<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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.test.cloud</groupId>
        <artifactId>test-cloud-client</artifactId>
        <version>1.0-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>test-cloud-client</name>
        <url>http://maven.apache.org</url>
        <parent>
            <groupId>com.test.cloud</groupId>
            <artifactId>test-cloud-parent</artifactId>
            <version>1.0.RELEASE</version>
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-ribbon</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-feign</artifactId>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <configuration>
                        <source>1.8</source>
                        <target>1.8</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                    <executions>
                        <execution>
                            <goals>
                                <goal>repackage</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <mainClass>com.hytera.test.cloud.App</mainClass>
                        <fork>true</fork>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    </project>

10.discovery-client 配置

server:
      port: 9061
    eureka:
      client:
        service-url:
          defaultZone : http://192.168.72.30:9080/eureka/
      instance:
        prefer-ip-address: true
        lease-expiration-duration-in-seconds: 15
        lease-renewal-interval-in-seconds: 5
        #instance-id: ${spring.application.name}:${server.port}
        instance-id: ${spring.cloud.client.ipAddress}:${server.port}
    spring:
      application:
        name: cloudclient

11.discovery-client 入口

package com.test.cloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.client.RestTemplate;
    
    /**
     * Hello world!
     * @author Administrator
     */
    @SpringBootApplication
    @EnableDiscoveryClient
    public class App {
        @Bean
        @LoadBalanced
        RestTemplate restTemplate() {
            return new RestTemplate();
        }
    
        public static void main(String[] args) {
            SpringApplication.run(App.class, args);
        }
    }

12.discovery-client 服务消费类

package com.test.cloud;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    /**
     *
     * @author Administrator
     * @date 2017/11/22
     */
    @RestController
    public class ConsumerController {
        @Autowired
        private RestTemplate restTemplate;
        @RequestMapping(value = "/add", method = RequestMethod.GET)
        public String add() {
            return restTemplate.getForEntity("http://Eureka-Server/getMsgInfo?strGuid=10&strUserName=20", String.class).getBody();
        }
    }

全部代码完成。

访问discovery-client ，会使用自身软负载功能进行选择server。

[Image 1]: