Spring Cloud Eureka快读入门Demo

1.什么是Eureka？

Eureka 由 Netflix 开发，是一种基于REST（Representational State Transfer）的服务，用于定位服务（服务注册与发现），以实现中间层服务的负载均衡和故障转移，此服务被称为 Eureka Server。同时，它还附带了基于 Java 的客户端组件：Eureka Client，它使得客户端与 Eureka Server 的交互变得更加的容易。 以下就是一个简单的服务调用过程：

1. 由服务提供方将服务注册到 Eureka Server
2. 服务消费者通过 Eureka Server 获取服务提供方的真实地址
3. 服务消费者通过真实的地址调用服务

2.代码工程

实验目的

搭建Eureka集群

pom.xml

<?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>eureka</artifactId>
        <groupId>com.et</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka-server</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            <version>${eureka.version}</version>
        </dependency>
    </dependencies>

</project>

EurekaServerApplication

package com.et.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {

  public static void main(String[] args) {
    SpringApplication.run(EurekaServerApplication.class, args);
  }
}

节点1配置信息

server:
  port: 8761

eureka:
  instance:
    hostname: node1 # eureka name
    prefer-ip-address: false
  client:
    fetch-registry: false
    register-with-eureka: true
    # eureka url
    service-url:
      defaultZone: http://node2:8762/eureka
spring:
  application:
    name: "eureka-server-ha"

节点2配置信息

server:
  port: 8762

eureka:
  instance:
    hostname: node2 # eureka name
    prefer-ip-address: false
  client:
    fetch-registry: false
    register-with-eureka: true
    # eureka url
    service-url:
      defaultZone: http://node1:8761/eureka
spring:
  application:
    name: "eureka-server-ha"

配置本机host

/etc/hosts

127.0.0.1 node1
127.0.0.1 node2

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

• GitHub - Harries/springcloud-demo: Spring Cloud tutorial about hystrix,eureka,config,admin,skywalking

3.测试

启动node1，node2

访问http://127.0.0.1:8761/

4.引用

• Spring Cloud Netflix
• Spring Cloud 3: Eureka Clustering | Nick Li
• Spring Cloud Eureka快读入门Demo | Harries Blog™