SpringCloud之Eureka
【前面的话】SpringCloud为开发人员提供了快速构建分布式系统的一些工具,包括配置管理、服务发现、断路器、路由、微代理、事件总线、全局锁、决策竞选、分布式会话等等。它配置简单,上手快,而且生态成熟,便于应用。但是它对SpringBoot有很强的依赖,需要有一定基础,但是SpringBoot俩小时就可以入门。另外对于“微服务架构” 不了解的话,可以通过搜索引擎搜索“微服务架构”了解下。另外这是SpringCloud的版本为Greenwich.SR2,JDK版本为1.8,SpringBoot的版本为2.1.7.RELEASE。
壹、新建父工程
- 新建一个Maven父工程lovincloud,便于版本管理,然后删除src文件夹
- 添加pom依赖和SpringCloud和SpringBoot的版本
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.7.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.eelve.lovincloud</groupId>
<artifactId>lovincloud</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>lovincloud</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring-cloud.version>Greenwich.SR2</spring-cloud.version>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
贰、添加一个注册中心
在这里,我们需要用的的组件上Spring Cloud Netflix的Eureka ,eureka是一个服务注册和发现模块。
- 新建一个子工程lovin-eureka-server作为服务的注册中心
<parent>
<artifactId>lovincloud</artifactId>
<groupId>com.eelve.lovincloud</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>lovin-eureka-server</artifactId>
<packaging>jar</packaging>
<name>eurekaserver</name>
<version>0.0.1</version>
<description>eureka服务端</description>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
- 然后在启动类上添加@EnableEurekaServer注解:
package com.eelve.lovin;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
/**
* @ClassName LovinEurekaServerApplication
* @Description TDO
* @Author zhao.zhilue
* @Date 2019/8/15 16:20
* @Version 1.0
**/
@EnableEurekaServer
@SpringBootApplication
public class LovinEurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(LovinEurekaServerApplication.class,args);
}
}
- eureka是一个高可用的组件,它没有后端缓存,每一个实例注册之后需要向注册中心发送心跳(因此可以在内存中完成),在默认情况下erureka server也是一个eureka client ,必须要指定一个 server。eureka server的配置文件appication.yml:
spring:
application:
naem: lovineurkaserver # 服务模块名称
server:
port: 8881 # 设置的eureka端口号
eureka:
instance:
hostname: localhost # 设置eureka的主机地址
client:
registerWithEureka: false #表示是否将自己注册到Eureka Server,默认为true。由于当前应用就是Eureka Server,故而设置为false
fetchRegistry: false #表示是否从Eureka Server获取注册信息,默认为true。因为这是一个单点的Eureka Server,不需要同步其他的Eureka Server节点的数据,故而设置为false
serviceUrl:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ #Eureka server地址,查询服务和注册服务都需要依赖这个地址,多个地址可用逗号(英文的)分割
叁、添加一个服务消费端
- 新建一个子工程lovin-eureka-server作为服务的注册中心
<parent>
<artifactId>lovincloud</artifactId>
<groupId>com.eelve.lovincloud</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>lovin-eureka-client</artifactId>
<packaging>jar</packaging>
<name>eurekaclient</name>
<version>0.0.1</version>
<description>eureka的一个消费端</description>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
- 然后在启动类上添加@EnableEurekaClient注解:
package com.eelve.lovin;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
/**
* @ClassName LovinEurekaClientApplication
* @Description TDO
* @Author zhao.zhilue
* @Date 2019/8/15 16:37
* @Version 1.0
**/
@SpringBootApplication
@EnableEurekaClient
public class LovinEurekaClientApplication {
public static void main(String[] args) {
SpringApplication.run(LovinEurekaClientApplication.class,args);
}
}
- 然后我们需要连接到服务端,具体配置如下
server:
port: 8801 # 服务端口号
spring:
application:
name: lovineurkaclient # 服务名称
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8881/eureka/ # 注册到的eureka服务地址
- 新建一个Controller写一个测试接口
package com.eelve.lovin.controller;
import com.eelve.lovin.config.ServerConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* @ClassName HelloController
* @Description TDO应用默认访问接口
* @Author zhao.zhilue
* @Date 2019/8/15 16:45
* @Version 1.0
**/
@RestController
public class HelloController {
@Autowired
ServerConfig serverConfig;
@RequestMapping("hello")
public String hello(){
return serverConfig.getUrl()+"###"+ HelloController.class.getName();
}
}
肆、分别启动注册中心的服务端和客户端
访问localhost:8881查看结果
到这里我们可以已经看到已经成功将客户端注册到服务端了,然后我们访问测试接口
可以看到已经访问成功,至此Eureka的搭建已经完成。
伍、加入安全配置
在互联网中我们一般都会考虑安全性,尤其是管理服务的注册中心,所以我们可以用spring-boot-starter-security来做安全限制
- 给lovin-eureka-server添加spring-boot-starter-security的pom依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
- 修改配置文件
spring:
application:
naem: lovineurkaserver # 服务模块名称
security:
basic:
enabled: true
user:
name: lovin
password: ${REGISTRY_SERVER_PASSWORD:lovin}
server:
port: 8881 # 设置的eureka端口号
eureka:
instance:
hostname: localhost # 设置eureka的主机地址
metadata-map:
user.name: ${security.user.name}
user.password: ${security.user.password}
client:
registerWithEureka: false #表示是否将自己注册到Eureka Server,默认为true。由于当前应用就是Eureka Server,故而设置为false
fetchRegistry: false #表示是否从Eureka Server获取注册信息,默认为true。因为这是一个单点的Eureka Server,不需要同步其他的Eureka Server节点的数据,故而设置为false
serviceUrl:
defaultZone: http://${spring.security.user.name}:${spring.security.user.password}@${eureka.instance.hostname}:${server.port}/eureka/ #Eureka server地址,查询服务和注册服务都需要依赖这个地址,多个地址可用逗号(英文的)分割
- 添加security配置
package com.eelve.lovin.config;
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;
/**
* @ClassName SecurityConfig
* @Description TDO
* @Author zhao.zhilue
* @Date 2019/8/16 14:13
* @Version 1.0
**/
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable();
http.authorizeRequests()
.antMatchers("/css/**").permitAll()
.anyRequest().authenticated()
.and()
.formLogin()
.and()
.httpBasic();
super.configure(http);
}
}
- 给lovin-eureka-client添加spring-boot-starter-security的pom依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
- 修改yaml配置文件
server:
port: 8801 # 服务端口号
spring:
application:
name: lovineurkaclient # 服务名称
security:
basic:
enabled: true
user:
name: lovin
password: ${REGISTRY_SERVER_PASSWORD:lovin}
eureka:
client:
serviceUrl:
defaultZone: http://lovin:lovin@localhost:8881/eureka/ # 注册到的eureka服务地址
instance:
leaseRenewalIntervalInSeconds: 10
health-check-url-path: /actuator/health
metadata-map:
user.name: lovin
user.password: lovin
- 添加security配置
package com.eelve.lovin.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
/**
* @ClassName SecurityConfig
* @Description TDO
* @Author zhao.zhilue
* @Date 2019/8/16 14:13
* @Version 1.0
**/
@Configuration
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http.authorizeRequests().anyRequest().permitAll()
.and().csrf().disable();
}
}
- 另外为了测试多客服端注册,我们可以修改再给客户端新建一个配置文件,然后开启IDEA的多节点运行,如下图所示勾选Allow parallel run
- 然后为了区分是哪个节点的请求我们可以添加获取端口
package com.eelve.lovin.config;
import org.springframework.boot.web.context.WebServerInitializedEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* @ClassName ServerConfig
* @Description TDO
* @Author zhao.zhilue
* @Date 2019/8/18 12:03
* @Version 1.0
**/
@Component
public class ServerConfig implements ApplicationListener<WebServerInitializedEvent> {
private int serverPort;
public String getUrl() {
InetAddress address = null;
try {
address = InetAddress.getLocalHost();
} catch (UnknownHostException e) {
e.printStackTrace();
}
return "http://"+address.getHostAddress() +":"+this.serverPort;
}
@Override
public void onApplicationEvent(WebServerInitializedEvent event) {
this.serverPort = event.getWebServer().getPort();
}
}
- 然后我们一次重启服务端和两个客户端,这个时候我们访问http://localhost:8881/
可以看到,这里已经让我们输入用户名和密码了,说明spring-boot-starter-security已经配置成功,这时我们输入配置的用户名:lovin和密码:lovin
这里我们可以看到已经成功了,那么到这里Eureka的配置已经全部成功了。 - 最后的最后是本博客的源码,欢迎关注这一套SpringCloud的实践