Spring Cloud Eureka 服务注册与发现中心（一）

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]: