一個微服務的專案架構是要有要的基礎構件的,包括服務註冊與發現、服務消費、負載均衡、斷路器、智慧路由、配置管理等;這樣便能構件出一個簡單的微服務專案;

整理出一個簡單的微服務架構圖;

大家可以看在圖中Zuul就充當著路由轉發的角色

不止如此,Zuul還具備很多功能:

Authentication / Insights / Stress Testing / Canary Testing / Dynamic Routing / Service Migration   / Load Shedding  /Security   / Static Response handling  / Active / Active traffic management等;

一.專案準備;

我們繼續沿用上一篇文章的工程;在此基礎上我們建立一個新的Model;

二.建立service-zuuul

同樣的,建立一個SpringBoot專案的Model;命名service-zuul;

pomy依賴如下;

<?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.example</groupId>
   <artifactId>demo</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>demo</name>
   <description>Demo project for Spring Boot</description
 
>

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.2.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
   </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-eureka</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-zuul</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</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>Dalston.RC1</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>

   <repositories>
      <repository>
         <id>spring-milestones</id>
         <name>Spring Milestones</name>
         <url>https://repo.spring.io/milestone</url>
         <snapshots>
            <enabled>false</enabled>
         </snapshots>
      </repository>
   </repositories>

</project>

properties配置檔案如下;

#服務埠
server.port=8886

#註冊服務中心地址
eureka.client.service-url.defaultZone=http://localhost:8880/eureka/

#註冊服務端name
spring.application.name=service-zuul

#/api-a的服務呼叫ribbon
zuul.routes.api-a.path=/api-a/**
zuul.routes.api-a.serviceId= service-ribbon

#/api-b的服務呼叫feign
zuul.routes.api-b.path=/api-b/**
zuul.routes.api-b.serviceId= service-feign

我們在啟動類上貼@EnableZuulProxy,表示開啟Zuul功能;

@EnableZuulProxy          //開啟zuul的功能：
@EnableEurekaClient
@SpringBootApplication
public class ZuulApplication {

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

這時候我們啟動Eureka,service-hello(兩個例項),service-ribbon,service-fegin,最後啟動service-zuul;

我們訪問 http://localhost:8886/api-a/hello  和  http://localhost:8886/api-b/hello

會看到如下結果:

這就說明了我們的zuul專案起到了路由作用,

三,Zuul的過濾功能;

下面我們來實踐Zuul的過濾功能;通過其過濾功能我們可以做一些安全驗證,資料加解密,登入驗證等等需求;

我們只需自定義個類;並繼承ZuulFilter即可;

程式碼如下:

/**
 * 用zuul做過濾
 */

@Component
public class MyFilter extends ZuulFilter {

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


    //filterType：返回一個字串代表過濾器的型別
    @Override
    public String filterType() {
        return "pre";      //pre：路由之前   routing：路由之時  post： 路由之後  error：傳送錯誤呼叫
    }

    //filterOrder：過濾的順序
    @Override
    public int filterOrder() {
        return 0;
    }


    //這裡可以寫邏輯判斷，是否要過濾，本文true,永遠過濾
    @Override
    public boolean shouldFilter() {
        return true;
    }


    //過濾器的具體邏輯。可以查sql，nosql去判斷該請求到底有沒有許可權訪問。
    @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("token is empty");
            }catch (Exception e){}

            return null;
        }
        log.info("ok");
        return null;
    }
}

此時我們重啟service-zuul;訪問連線   http://localhost:8886/api-a/hello

就會通過過濾功能驗證,token為空,達到token的驗證效果;

我們再帶上token來訪問; http://localhost:8886/api-a/hello?token=888

此時便通過驗證,訪問服務;

官方文件:

router_and_filter_zuul