Spring Cloud Zuul

心已赠人 2022-05-25 03:39 153阅读 0赞

**Spring Cloud Zuul 是实现 API 网关的功能**

<?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>service-zuul</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
    
        <name>service-zuul</name>
        <description>Demo project for Spring Cloud</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.12.RELEASE</version>
            <relativePath/> 
        </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>Edgware.SR3</spring-cloud.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <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.cloud</groupId>
                <artifactId>spring-cloud-starter-config</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-bus-amqp</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-zipkin</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>${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>

application.yml

server:
      port: 8086
      context-path: /service-zuul
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8081/eureka-server/eureka/
    # spring.application.name,这个很重要，在以后的服务与服务之间相互调用一般都是根据这个name
    spring:
      application:
        name: service-zuul
    # 如果报超时的话，可以添加下面的配置
    ribbon:
    # 创建请求连接超时
      ConnectTimeout: 3000
    # 请求连接建立后的处理超时
      ReadTimeout: 60000
    # 开启 @EnableZuulProxy 注解,会启用routes 和 filters 2个端点(/routes?format=details 可以得到更详细的信息)
    # zuul.routers.<serviceId>=<path> (等同于 zuul.routers.<name>.<path>=... 加 zuul.routers.<name>.<serviceId>=... )
    # 如果要调用的服务配置了 context-path,则需要在path中加上(例如: http://localhost:8086/service-zuul/feign/service-feign/hi/qw)
    zuul:
    #默认是false(第一次调用时才加载),true(项目启动时就加载);注意是配在zuul下面的(直接配ribbon.eager-load.enabled=true无效),这里没有提示的
      ribbon:
        eager-load:
          enabled: true
      routes:
        service-ribbon: /ribbon/** service-feign: /feign/** # true表示在路由转发前为请求设置Host头信息,以标识最初的服务端请求地址 add-host-header: true

添加 **@EnableZuulProxy**

继承 **ZuulFilter** 并实现它定义的4个抽象方法，就可以完成对请求的拦截和过滤了

@Component
    public class MyFilter extends ZuulFilter { 
        private static final Logger logger = LoggerFactory.getLogger(MyFilter.class);
    
        /*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：请求被路由之前调用 routing：路由请求时调用 post：在routing和error之后被调用 error：处理请求时发生错误时调用 filterOrder：过滤的顺序(数字越小优先级越高) shouldFilter：这里可以写逻辑判断,是否要过滤 run：过滤器的具体逻辑.可以很复杂,包括查sql,nosql去判断该请求到底有没有权限访问,或在请求路由返回结果之后,对处理结果进行一些加工 */
    
        @Override
        public String filterType() {
            // 可以使用这个常量类FilterConstants.PRE_TYPE
            return PRE_TYPE;
        }
    
        @Override
        public int filterOrder() {
            return 0;
        }
    
        @Override
        public boolean shouldFilter() {
            return true;
        }
    
        @Override
        public Object run() {
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletRequest request = ctx.getRequest();
            logger.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
            String token = request.getParameter("token");
            if (token == null || "".equals(token.trim())) {
                logger.error("token is empty!");
                ctx.setSendZuulResponse(false);
                ctx.setResponseStatusCode(401);
                ctx.setResponseBody("token is empty!");
                return null;
            }
            logger.info("ok!");
            return null;
        }
    }

Zuul 默认实现了很多过滤器  
![这里写图片描述][70]

可以通过配置来禁用过滤器: zuul.<过滤器类名>.<过滤器类型>.disable=true

#zuul.MyFilter.pre.disable=true

## 这里可以使用Spring Cloud Config 实现动态路由 ##

如果对 Spring Cloud Config 不太了解的可以先看看这个 [Spring Cloud Config][]

bootstrap.properties

server.port=8086
    server.context-path=/api-gateway
    # Git仓库中的配置文件名为name-<profile>,例如(api-gateway-dev.properties,api-gateway-test.properties)
    spring.application.name=api-gateway
    eureka.client.service-url.defaultZone=http://localhost:8081/eureka-server/eureka/
    #配置仓库的分支
    spring.cloud.config.label=master
    #根据 profile 查找对应的配置文件
    spring.cloud.config.profile=dev
    #必须设为true,否则还是会从 http://localhost:8888 获取配置
    spring.cloud.config.discovery.enabled=true
    #指定配置中心的服务名,即 config-server 的 spring.application.name
    spring.cloud.config.discovery.service-id=config-server
    #设为true,如果无法连接config server,启动时会抛异常,并停止服务
    spring.cloud.config.failFast=true
    #显示每个服务实例发送的所有事件和所有的ack
    spring.cloud.bus.trace.enabled=true
    # 使用 spring boot admin 时,如果设置了 server.context-path,需要配置下面2个,否则在admin server 无法获取完整的监控数据
    eureka.instance.metadata-map.management.context-path=${server.context-path}
    eureka.instance.metadata-map.management.context-port=${server.port}

application.properties

management.security.enabled=false
    # 禁用过滤器: 配置 zuul.<过滤器类名>.<过滤器类型>.disable=true
    #zuul.MyFilter.pre.disable=true
    # RabbitMQ 配置
    spring.rabbitmq.host=ip
    spring.rabbitmq.port=5672
    spring.rabbitmq.username=qinwei
    spring.rabbitmq.password=qinwei
    spring.rabbitmq.virtual-host=spring

@EnableZuulProxy
    @EnableEurekaClient
    @SpringBootApplication
    public class ServiceZuulApplication { 
        public static void main(String[] args) {
            SpringApplication.run(ServiceZuulApplication.class, args);
        }
    
        /** * 必须要加上@RefreshScope 注解 */
        @Bean
        @RefreshScope
        @ConfigurationProperties("zuul")
        public ZuulProperties zuulProperties() {
            return new ZuulProperties();
        }
    }

git 仓库中的 **api-gateway-dev.properties**

zuul.routes.ribbon.path=/ribbon/** zuul.routes.ribbon.serviceId=service-ribbon zuul.routes.feign.path=/feign/** zuul.routes.feign.serviceId=service-feign

[70]: /images/20220525/ad4622b9038c4f5fb188dc9a8e29fbba.png
[Spring Cloud Config]: https://blog.csdn.net/sinat_38843093/article/details/80227782