服务网关是微服务架构中一个不可或缺的部分。通过服务网关统一向外系统提供REST API的过程中，除了具备服务路由、均衡负载功能之外，它还具备了权限控制等功能。Spring Cloud Netflix中的Zuul就担任了这样的一个角色，为微服务架构提供了前门保护的作用，同时将权限控制这些较重的非业务逻辑内容迁移到服务路由层面，使得服务集群主体能够具备更高的可复用性和可测试性。
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.packtpub</groupId> <artifactId>Zuul</artifactId> <version>1.0.0</version> <packaging>jar</packaging> <name>Zuul</name> <description>com.packtpub.Zuul</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.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-zuul</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Camden.SR6</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>
application.properties
spring.application.name=api-gateway
server.port=5555
zuul.routes.api-b.path=/compute-service/**
zuul.routes.api-b.serviceId=compute-service
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
AccessFilter.java
package com.packtpub.Zuul; import javax.servlet.http.HttpServletRequest; import org.apache.log4j.Logger; import org.apache.log4j.spi.LoggerFactory; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; public class AccessFilter extends ZuulFilter { @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(); Object accessToken = request.getParameter("accessToken"); if(accessToken == null) { ctx.setSendZuulResponse(false); ctx.setResponseStatusCode(401); return null; } return null; } }
ZuulApplication.java
package com.packtpub.Zuul; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.SpringCloudApplication; import org.springframework.cloud.netflix.zuul.EnableZuulProxy; import org.springframework.context.annotation.Bean; @EnableZuulProxy @SpringCloudApplication public class ZuulApplication { public static void main(String[] args) { SpringApplication.run(ZuulApplication.class, args); } @Bean public AccessFilter accessFilter() { return new AccessFilter(); } }