springCloud Finchley 微服务架构从入门到精通【九】路由网关zuul

超、凢脫俗 2023-10-17 21:20 69阅读 0赞

\#\#一、网关简介\#\#  
\#\#\#1、zuul的作用\#\#\#  
在微服务架构中，一个系统会有多个微服务，例如service-user, service-shop，一个功能往往需要调用多个微服务来完成，zuul实现的网关类似于设计模式中的门面模式Facade，通常在网关层实现功能：

**- 认证** 来源的合法性校验  
**- 动态路由** 隐藏内部接口，通过调用所配置路径转发至各微服务接口  
**- 安全** 权限校验  
**- 服务迁移** 简单化因业务变化而需要拆分/整合服务的工作  
\#\#\#2、架构图\#\#\#  
zuul 像其他微服务一样作为一个微服务向eureka server注册，并且能够通过注册列表获取所有的可用服务，其内部默认实现了ribbon，可达到负载均衡的目的，此时的微服务架构图如下：

![这里写图片描述][70]

无论是pc还是移动端调用首先经过zuul网关层，在这里会有一系列的filter（例如权限控制，接口认证等），验证合法后zuul放行并调用相关的微服务接口，在此架构中，需要说明通常的部署方法：**zuul网关在系统的最外层暴露映射后的地址供外部客户端调用，而使用内部私有地址调用各微服务**

\#\#二、代码实现\#\#  
\#\#\#1、添加依赖\#\#\#  
zuul的配置还是放到配置中心统一管理，因此需要加入配置客户端、eureka客户端和zuul 依赖

<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-config</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
    		</dependency>

\#\#\#2、bootstrap.yml\#\#\#

spring: 
      application:
        name: service-zuul
      cloud:
        config:
          discovery: 
            enabled: true
            service-id: service-config
          label: master
          profile: dev

\#\#\#3、配置中心service-zuul-dev.yml\#\#\#

server:
      port: 1100
    zuul: 
      ignoredServices: '*' #忽略所有未配置的service
      host:
        connect-timeout-millis: 20000
        socket-timeout-millis: 20000
      routes:
        user-service: #自定义名称
          path: /user/**
          serviceId: service-user #/user/开头的路径转发至service-user微服务
    hystrix: #hystrix配置
      command:
        default:
          execution:
            isolation:
              thread:
                timeoutInMilliseconds: 2500 
    ribbon: #ribbon负载均衡参数配置
      ReadTimeout: 5000
      ConnectTimeout: 5000s
    eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8761/eureka/

\#\#\#4、启动类\#\#\#  
**在启动类CommonserviceZuulApplication添加注解@EnableZuulProxy以开启zuul特性：**

package com.mayi.springcloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableZuulProxy
    public class CommonserviceZuulApplication {
        
    
    	public static void main(String[] args) {
        
    		SpringApplication.run(CommonserviceZuulApplication.class, args);
    	}
    }

\#\#\#5、熔断\#\#\#  
**创建一个熔断类：UserFallbackProvider, 代码取自官方文档最简单实现**

package com.mayi.springcloud.fallback;
    
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    
    import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.client.ClientHttpResponse;
    import org.springframework.stereotype.Component;
    @Component
    public class UserFallbackProvider implements FallbackProvider{
        
    
    	@Override
    	public String getRoute() {
        
    		return "service-user";
    	}
    
    	@Override
    	public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        
    		return new ClientHttpResponse() {
        
    			
    			@Override
    			public HttpHeaders getHeaders() {
        
    				HttpHeaders headers = new HttpHeaders();
                    headers.setContentType(MediaType.APPLICATION_JSON);
                    return headers;
    			}
    			
    			@Override
    			public InputStream getBody() throws IOException {
        
    				return new ByteArrayInputStream("fallback".getBytes());
    			}
    			
    			@Override
    			public String getStatusText() throws IOException {
        
    				return "OK";
    			}
    			
    			@Override
    			public HttpStatus getStatusCode() throws IOException {
        
    				return HttpStatus.OK;
    			}
    			
    			@Override
    			public int getRawStatusCode() throws IOException {
        
    				return 200;
    			}
    			
    			@Override
    			public void close() {
        
    				
    			}
    		};
    	}
    
    }

\#\#\#四、测试\#\#\#  
**依次启动eureka、config、user、zuul ，user启动两个节点**

![这里写图片描述][70 1]

**访问：http://localhost:1100/user/listUsers**

![这里写图片描述][70 2]

**发现映射到了service-user微服务的listUsers接口，并实现了负载均衡。**

**此时，断掉其中一个service-user节点，继续访问以上地址**

![这里写图片描述][70 3]

数秒后，故障节点被剔除

源码下载：https://github.com/tianyana/springcloud/tree/master/commonservice-zuul

[70]: https://img-blog.csdn.net/20180510181633665?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 1]: https://img-blog.csdn.net/20180510181712419?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 2]: https://img-blog.csdn.net/2018051018172345?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70
[70 3]: https://img-blog.csdn.net/20180510181732763?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3djYmxvZw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70