微服务系列(1)-使用SpringCloud搭建Eureka注册中心

一、前言

Spring Cloud是一套完整的开源的微服务解决方案，它提供了诸多的微服务组件，基于springBoot开箱即用。今天先介绍一下微服务中最重要的组件注册中心。本片文章将使用Eureka搭建一个简单的注册中心。

二、开发工具及相关版本号

开发工具	版本号
idea	2018.2.4
spring boot	2.1.3
spring cloud	Greenwich.RELEASE
java	1.8

三、开始写代码

1. 新建一个spring-boot项目,引入如下依赖

<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>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.1.3.RELEASEversion>
        <relativePath/> 
    parent>
    <groupId>com.examplegroupId>
    <artifactId>demoartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>demoname>
    <description>Demo project for Spring Bootdescription>

    <properties>
        <java.version>1.8java.version>
        <spring-cloud.version>Greenwich.RELEASEspring-cloud.version>
    properties>

    <dependencies>
    	
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-netflix-eureka-serverartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-securityartifactId>
        dependency>
    dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>${spring-cloud.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
        dependencies>
    dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>

    <repositories>
        <repository>
            <id>spring-milestonesid>
            <name>Spring Milestonesname>
            <url>https://repo.spring.io/milestoneurl>
        repository>
    repositories>

project>

2. 添加配置文件 application.yml

server:
 port: 8080
eureka:
 instance:
   hostname: localhost
 client:
   # 表示是否注册自身到eureka服务器
    register-with-eureka: false
   # 是否从eureka上获取注册信息
    fetch-registry: false
   service-url:
     defaultZone: http://admin:admin@localhost:8081/eureka/
 server:
   enable-self-preservation: false
spring:
 security:
   user:
     name: admin
     password: admin
 application:
    name: eureka-server

3. 启动类上添加@EnableEurekaServer注解

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

@EnableEurekaServer
@SpringBootApplication
public class DemoApplication {

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

}

4. 配置spring Security关闭CSRF,新版的Secrity默认开启了CSRF如果不关闭会导致认证403，服务注册不到注册中心

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@EnableWebSecurity
@Configuration
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable(); //关闭csrf
        http.authorizeRequests().anyRequest().authenticated().and().httpBasic(); //开启认证
    }

}

5. 启动项目
   浏览器输入：http://localhost:8080
   看到下图便成功了
   

四、注意事项

1. 在配置注册中心时，处于安全的考虑便添加了spring-security框架，所以在访问localhost:8080时需要认证，认证的用户名、密码在配置文件中已配置。
2. 新版的spring-security框架默认开启了CSRF,一定记得关闭！

五、小节

Spring Cloud是一套开箱即用的微服务工具箱，所以在使用的过程中还是很简单的 !
本项目的代码以上传至GitHub，地址：俞兆鹏的GitHub