@Spring Cloud | NO.3 - 路由器和过滤器 Zuul

什么是Zuul

路由是微服务体系结构的一个组成部分。例如，/可以映射到您的Web应用程序，/api/users映射到用户服务，并将/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。

Netflix使用Zuul进行以下操作：

认证
洞察
压力测试
金丝雀测试
动态路由
服务迁移
负载脱落
安全
静态响应处理
主动/主动流量管理

Zuul的规则引擎允许基本上写任何JVM语言编写规则和过滤器，内置Java和Groovy。

以上内容官方直译

项目集成之`Zuul`

1. pom.xml引入Maven依赖

<parent>
    <!-- spring boot -->
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.1.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>
        <!-- netflix-eureka-client-->
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <!-- netflix-zuul -->
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <!-- spring cloud -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley RC1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

注意： Zuul引入的Maven依赖中artifactId有变动，SpringBoot2.0之前的版本为spring-cloud-starter-zuul

2. 添加注解支持

@EnableZuulProxy
@EnableDiscoveryClient
@SpringBootApplication
public class ZuulServiceApplication {

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

3. `application.yml`配置

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8769
spring:
  application:
    name: service-zuul
zuul:
  routes:
    api-a:
      path: /api-a/**
      serviceId: service-ribbon
    api-b:
      path: /api-b/**
      serviceId: service-feign