Spring cloud 微服务架构 Eureka篇

Posted 2020-10-08 Antony

1 服务发现

## 关于服务发现

在微服务架构中，服务发现（Service Discovery）是关键原则之一。手动配置每个客户端或某种形式的约定是很难做的，并且很脆弱。Spring Cloud提供了多种服务发现的实现方式，例如：Eureka、Consul、Zookeeper。

Spring Cloud支持得最好的是Eureka，其次是Consul，最次是Zookeeper。

2、创建一个Maven工程（microservice-discovery-eureka），并在pom.xml中加入如下内容

<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>

    <artifactId>microservice-discovery-eureka</artifactId>
    <packaging>jar</packaging>

    <parent>
        <groupId>com.xujin.study</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
    </dependencies>
</project>

3、创建启动类 EurekaApplication 

package com.xujin.study;

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

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaApplication.class, args);
    }
}

4、配置Eureka

server:
  port: 8761                    # 指定该Eureka实例的端口
security:
  basic:
    enabled: true
  user:
    name: root
    password: root
eureka:
  instance:
    hostname: discovery         # 指定该Eureka实例的主机名
  client:
    registerWithEureka: false
    fetchRegistry: false
    serviceUrl:
      defaultZone: http://${security.user.name}:${security.user.password}@${eureka.instance.hostname}:${server.port}/eureka/

5、启动工程后，访问：[http://127.0.0.1:8761/]  输入你配置的用户名和密码进入Eureka页面