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Spring Cloud 之 路由网关 Zuul组件

程序员文章站 2022-06-13 21:20:29
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Netflix又一开源Spring Cloud组件,路由网关Zuul。
微服务架构下服务众多,Zuul能将所有服务的API接口统一聚合,向外暴露,用户看起来就像在访问一个服务一样。隐藏了内部服务跳转的过程。还可以和Ribbon组合实现智能路由转发和负载均衡的功能。Zuul还可以用来做身份认证,权限过滤等等。实现流量监控,日志记录等等功能。
Zuul通过自己的ZuulServlet(类似于Spring MVCde DispatcherServlet)来对请求进行转发控制。
Zuul的4中过滤器:

  • PRE:在请求路由到具体服务之前执行,用来做安全验证
  • ROUTING:将请求路由到具体服务
  • POST:在请求已被路由到具体服务后执行,收集数据,监控信息
  • ERROR:在其它过滤器发生错误时执行

当一个Request请求进入Zuul网关服务,先进入PRE,进行验证操作,然后进入ROUTING进行路由转发。转发到具体服务实例进行逻辑处理,处理完后,然后进入POST,做数据统计(性能指标等等),最后将Response返回给客户端。

Zuul官方文档


1、搭建Zuul

在前面几篇博客的基础上新增一个model:server-zuul
*注意主工程依赖
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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.service</groupId>
    <artifactId>zuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>server-zuul</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>com.cloud</groupId>
        <artifactId>test</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
    </properties>

    <dependencies>
        <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>
    </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>
</project>

应用主类添加注解:@EnableZuulProxy(或者@EnableZuulServe),区别参考官方文档18.16.3节

@SpringBootApplication
@EnableZuulProxy
public class ZuulApplication {

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

application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:7777/eureka/
server:
  port: 8888
spring:
  application:
    name: service-zuul
zuul:
  routes:
    #配置对应路径转发到具体服务
    api-a:
      path: /api-ribbon/**
      serviceId: service-ribbon
    api-b:
      path: /api-feign/**
      serviceId: service-feign

实现一个简单的过滤器
MyFilter 验证一个name参数是否存在。

package com.service.zuul.filter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

/**
 * Author: RoronoaZoro丶WangRui
 * Time: 2018/7/17/003
 * Describe:
 */
@Component
public class MyFilter extends ZuulFilter {

    private static Logger log = LoggerFactory.getLogger(MyFilter.class);

    @Override
    public String filterType() {
        return "pre";
    }

    @Override
    public int filterOrder() {
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    /**
     * filterType:返回一个字符串代表过滤器的类型,在zuul中定义了四种不同生命周期的过滤器类型,具体如下:
     * pre:路由之前
     * routing:路由之时
     * post: 路由之后
     * error:发送错误调用
     * filterOrder:过滤的顺序
     * shouldFilter:这里可以写逻辑判断,是否要过滤,本文true,永远过滤。
     * run:过滤器的具体逻辑。可用很复杂,包括查sql,nosql去判断该请求到底有没有权限访问。
     * 访问测试:http://localhost:8888/api-feign/hi?name=forezp||http://localhost:8888/api-feign/hi?name=forezp&token=22
     * @return
     * @throws ZuulException
     */
    @Override
    public Object run() throws ZuulException {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        log.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
        Object accessToken = request.getParameter("name");
        if (accessToken == null) {
            log.warn("name is empty");
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(401);
            try {
                ctx.getResponse().getWriter().write("name is empty");
            } catch (Exception e) {
            }
            return null;
        }
        log.info("ok");
        return null;
    }
}

2、测试

依次启动eureka-server,eureka-client,service-ribbon,service-feign,server-zuul。其中eureka-client启动两个实例,为了测试负载均衡。
Spring Cloud 之 路由网关 Zuul组件
访问:http://localhost:8888/api-feign/hi?name=mistra或者http://localhost:8888/api-ribbon/hi?name=mistra
浏览器交替输出:hi mistra,i am from port:8003和hi mistra,i am from port:8002
当访问不带name参数时:http://localhost:8888/api-ribbon/hi
浏览器输出:name is empty

源码


Spring Cloud 之 路由网关 Zuul组件

相关标签: zuul springcloud