Spring Cloud学习笔记5-Zuul服务网关

╰半夏微凉° 2022-04-04 11:16 184阅读 0赞

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title: “Spring Cloud学习笔记5-Zuul服务网关”

url: “[https://wsk1103.github.io/][https_wsk1103.github.io]”

tags:

*  Spring Cloud
 *  学习笔记

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#### 备注： ####

**官网**：[http://spring.io/projects/spring-cloud][http_spring.io_projects_spring-cloud]

**总纲**：[https://cloud.spring.io/spring-cloud-static/Finchley.SR2/single/spring-cloud.html][https_cloud.spring.io_spring-cloud-static_Finchley.SR2_single_spring-cloud.html]

**JAVA**： 1.8 +

**MAVEN**： 3.5.0 +

**Spring Boot**：2.0.7.RELEASE

**Spring Cloud**：Finchley

说明：Routing is an integral part of a microservice architecture. For example, / may be mapped to your web application, /api/users is mapped to the user service and /api/shop is mapped to the shop service. Zuul is a JVM-based router and server-side load balancer from Netflix.

路由是微服务架构不可或缺的一部分。例如，/可以映射到您的Web应用程序，/api/users映射到用户服务，/api/shop映射到商店服务。Zuul是Netflix的基于JVM的路由器和服务器端负载均衡器。（谷歌翻译面）

Netflix uses Zuul for the following（有以下作用）:

*  Authentication（权限验证）
 *  Insights
 *  Stress Testing（压力测试）
 *  Canary Testing（灰度测试-金丝雀测试）
 *  Dynamic Routing（动态路由）
 *  Service Migration（服务迁移）
 *  Load Shedding（负载均衡）
 *  Security（安全）
 *  Static Response handling（处理静态响应)
 *  Active/Active traffic management（流量管理）

--------------------

本项目地址：[https://github.com/wsk1103/my-spring-cloud][https_github.com_wsk1103_my-spring-cloud]

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## 搭建服务zuul ##

搭建方法同学习笔记1中新建module

#### 1. 修改pom.xml ####

主要增加依赖为

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

具体pom

<?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.wsk</groupId>
        <artifactId>zuul</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>service-zuul</name>
        <description>Demo project for Spring Boot</description>
    
        <parent>
            <groupId>my-spring-cloud</groupId>
            <artifactId>MySpringCloud</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>
        </properties>
    
        <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>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    
    </project>

#### 2. 重命名application.properties为application.yml ####

eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/
    
    server:
      port: 8769
    
    spring:
      application:
        name: service-zuul
        
    # 路由控制，后续详解
    zuul:
      routes:
        a:
          path: /a/**
          serviceId: service-client
        b:
          path: /b/**
          serviceId: service-feign

#### 3. 修改ServiceZuulApplication ####

新增注解  
//开启服务网关  
@EnableZuulProxy  
@EnableEurekaClient  
@EnableDiscoveryClient

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

#### 4. 依次启动server，client，feign，zuul ####

访问：[http://localhost:8769/a/go?name=sky][http_localhost_8769_a_go_name_sky]  
，再访问：[http://localhost:8762/a/go?name=sky][http_localhost_8762_a_go_name_sky]

## 路由配置说明 ##

#### 1. 参数说明 ####

**路由配置基础参数**

<table> 
 <thead> 
  <tr> 
   <th>key</th> 
   <th>value</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>zuul.routes.{routename}</td> 
   <td>路由名称，自定义，支持小写字母、-</td> 
  </tr> 
  <tr> 
   <td>zuul.routes.{routename}.path</td> 
   <td>要路由的路径，支持通配符：?、 、*</td> 
  </tr> 
  <tr> 
   <td>zuul.routes.{routename}.serviceId</td> 
   <td>注册在Eureka的ServiceName</td> 
  </tr> 
  <tr> 
   <td>zuul.routes.{routename}.url</td> 
   <td>如果应用没有注册在Eureka，也可以通过指定Url来路由</td> 
  </tr> 
  <tr> 
   <td>zuul.ignored-services</td> 
   <td>忽略指定的服务,可以配置多个，以,间隔</td> 
  </tr> 
  <tr> 
   <td>zuul.ignored-patterns</td> 
   <td>忽略指定的路径，可以配置多个，以,间隔。同样支持通配符</td> 
  </tr> 
 </tbody> 
</table>

**path通配符说明**

<table> 
 <thead> 
  <tr> 
   <th>key</th> 
   <th>value</th> 
   <th>举例</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>?</td> 
   <td>匹配单个任意字符</td> 
   <td>/sk/?</td> 
   <td>/sk/a、/sk/b</td> 
  </tr> 
  <tr> 
   <td>*</td> 
   <td>匹配任意字符</td> 
   <td>sk/*</td> 
   <td>/sk/a、/sk/b、/sk/ab</td> 
  </tr> 
  <tr> 
   <td>**</td> 
   <td>匹配任意字符且支持多级目录</td> 
   <td>sk/**</td> 
   <td>/sk/a、/sk/b、/sk/ab、/sk/ab/c</td> 
  </tr> 
 </tbody> 
</table>

#### 实例说明 ####

1.  路由到注册到Eureka的服务

zuul:
      routes:
        client:
          path: /client/**
          serviceId: service-client

**说明：** 通过路径来指定服务的地址。一般用于拆分服务，也就是微服务。

该项目的配置说明

zuul:
      routes:
        a:
          path: /a/**
          serviceId: service-client
        b:
          path: /b/**
          serviceId: service-feign
        c:
          path: /**
          serviceId: service-feign

其中path中，将访问/a/\*\*的所有请求转发到service-client相应的接口，例如访问http://localhost:8769/a/go?name=sky，相对于访问service-client服务的go接口。  
/b/\*\*同理。

*PS*：路由规则匹配顺序是按配置顺序来的，所以未拆出去的配置在最后。  
2. 路由到指定站点

当服务没有注册到注册中心的时候，zuul是无法发现该服务的，但是这个时候我们又需要访问其他网站等等。

zuul:
      routes:
        sky:
          path: /sky/**
          url: https://wsk1103.github.io/

1.  忽略指定路径

通常适用于某些通用的接口不暴露给外部。这个时候外部就无法访问/**/a和/**/b下的路径。

zuul:
      ignored-patterns: /**/a,/**/b

1.  忽略指定服务

zuul:
      ignored-services: aservice,bservice

## zuul过滤器 ##

zuul不仅只是路由，并且还能过滤，做一些安全验证

#### 1. 新增包filter -> 新增类 MyFilter ####

该类继承ZuulFilter，并注解@Component

该过滤器的作用是访问的时候必须带上token，否则无法访问。

package com.wsk.zuul.filter;
    
    import com.netflix.zuul.ZuulFilter;
    import com.netflix.zuul.context.RequestContext;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.stereotype.Component;
    
    import javax.servlet.http.HttpServletRequest;
    
    /**
     * @author WuShukai
     * @version V1.0
     * @description
     * @date 2018/11/27  9:50
     */
    @Component
    @Slf4j
    public class MyFilter extends ZuulFilter {
    
        /**
         * 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。
         */
    
        @Override
        public String filterType() {
            return "pre";
        }
    
        @Override
        public int filterOrder() {
            return 0;
        }
    
        @Override
        public boolean shouldFilter() {
            return true;
        }
    
        @Override
        public Object run() {
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletRequest request = ctx.getRequest();
            log.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
            Object accessToken = request.getParameter("token");
            if (accessToken == null) {
                log.warn("token is empty");
                ctx.setSendZuulResponse(false);
                ctx.setResponseStatusCode(401);
                try {
                    ctx.getResponse().getWriter().write("{\"msg\": \"token is empty\"}");
                } catch (Exception e) {
                    log.error(e.getMessage(), e);
                }
    
                return null;
            }
            log.info("ok");
            return null;
        }
    }

#### 2. ZuulFilter使用说明 ####

**ZuulFilter方法说明**

<table> 
 <thead> 
  <tr> 
   <th>方法名</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>filterType()</td> 
   <td>过滤器类型：pre、routing、post、error</td> 
  </tr> 
  <tr> 
   <td>filterOrder</td> 
   <td>过滤器顺序，用于指定过滤器执行顺序</td> 
  </tr> 
  <tr> 
   <td>shouldFilter</td> 
   <td>是否要过滤，可以根据当前请求信息判断是否过滤，也可以默认返回true</td> 
  </tr> 
  <tr> 
   <td>run</td> 
   <td>过滤器执行逻辑，执行具体的过滤操作。</td> 
  </tr> 
 </tbody> 
</table>

**FilterType说明**

<table> 
 <thead> 
  <tr> 
   <th>type</th> 
   <th>说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>pre</td> 
   <td>在路由之前执行过滤</td> 
  </tr> 
  <tr> 
   <td>routing</td> 
   <td>在路由时执行过滤</td> 
  </tr> 
  <tr> 
   <td>post</td> 
   <td>在路由之后执行过滤</td> 
  </tr> 
  <tr> 
   <td>error</td> 
   <td>在发生错误时执行过滤</td> 
  </tr> 
 </tbody> 
</table>

### 参考 ###

1.  [https://ken.io/note/spring-cloud-zuul-quickstart][https_ken.io_note_spring-cloud-zuul-quickstart]
2.  [https://blog.csdn.net/forezp/article/details/81041012][https_blog.csdn.net_forezp_article_details_81041012]
3.  [https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.M3/single/spring-cloud-netflix.html\#\_router\_and\_filter\_zuul][https_cloud.spring.io_spring-cloud-static_spring-cloud-netflix_2.1.0.M3_single_spring-cloud-netflix.html_router_and_filter_zuul]

[https_wsk1103.github.io]: https://wsk1103.github.io/
[http_spring.io_projects_spring-cloud]: https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.0.2.RELEASE/single/spring-cloud-netflix.html#_router_and_filter_zuul
[https_cloud.spring.io_spring-cloud-static_Finchley.SR2_single_spring-cloud.html]: https://cloud.spring.io/spring-cloud-static/Finchley.SR2/single/spring-cloud.html
[https_github.com_wsk1103_my-spring-cloud]: https://github.com/wsk1103/my-spring-cloud
[http_localhost_8769_a_go_name_sky]: http://localhost:8769/a/go?name=sky
[http_localhost_8762_a_go_name_sky]: http://localhost:8762/a/go?name=sky
[https_ken.io_note_spring-cloud-zuul-quickstart]: https://ken.io/note/spring-cloud-zuul-quickstart
[https_blog.csdn.net_forezp_article_details_81041012]: https://blog.csdn.net/forezp/article/details/81041012
[https_cloud.spring.io_spring-cloud-static_spring-cloud-netflix_2.1.0.M3_single_spring-cloud-netflix.html_router_and_filter_zuul]: https://cloud.spring.io/spring-cloud-netflix/2.0.x/single/spring-cloud-netflix.html#_router_and_filter_zuul