SpringCloudGateway搭建和常见使用方法

**Spring Cloud Gateway：**提供一种简单而有效的方式来对API进行路由，并为他们提供切面，例如：安全性，监控/指标 和弹性等。

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1.如何在工程中引用Spring Cloud Gateway

• 引入jar包

  <dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId></dependency><!-- SpringCloud Ailibaba Nacos --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><!-- SpringCloud Ailibaba Nacos Config --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><!-- SpringBoot Actuator --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency>

• 配置注册中心地址

  spring:application:name: dyzh-gatewaycloud:nacos:discovery:enabled:trueregister-enabled:trueserver-addr: 127.0.0.1:8848

• 配置路由

  • Route 路由：gateway的基本构建模块。它由ID、目标URI、断言集合和过滤器集合组成。如果聚合断言结果为真，则匹配到该路由。
  • Predicate 断言：这是一个Java 8 Function Predicate。输入类型是 Spring FrameworkServerWebExchange。这允许开发人员可以匹配来自HTTP请求的任何内容，例如Header或参数。
  • Filter 过滤器：这些是使用特定工厂构建的 Spring FrameworkGatewayFilter实例。 。Spring cloud gateway中的filter分为两种类型的Filter，分别是Gateway Filter和Global Filter（全局）。过滤器Filter将会对请求和响应进行修改处理 所以可以在返回请求之前或之后修改请求和响应的内容。

  spring:cloud:gateway:discovery:locator:# 注册中心自动发现 默认为 falseenabled:false#手动配置路由routes:#路由id，可以自定义设置-id: dyzh-demo-service#目标URI， URI上的'lb`前缀,使用Spring Cloud Netflix Ribbon 客户端负载均衡。uri: lb://dyzh-demo-servicepredicates:- Path=/sys/**

2.Actuator API

/gateway的actuator端点允许监视Spring Cloud Gateway应用程序并与之交互。要进行远程访问，必须在应用程序属性中暴露HTTP或JMX 端口。

• 开启actuator

  management:endpoint:gateway:# 默认为falseenabled:trueendpoints:web:exposure:include: gateway

• 下表列出了Spring Cloud Gateway执行器端点（请注意，每个端点都/actuator/gateway作为基本路径）：

1.检索所有的路由【 global filters 】

curl -X GET http://localhost:your-port/actuator/gateway/globalfilters

返回结果如下：

{"org.springframework.cloud.gateway.filter.NettyWriteResponseFilter@195113de":-1,"org.springframework.cloud.gateway.filter.NettyRoutingFilter@1f15e689":2147483647,"org.springframework.cloud.gateway.filter.GatewayMetricsFilter@58feb6b0":0,"org.springframework.cloud.gateway.filter.AdaptCachedBodyGlobalFilter@3e900e1a":-2147482648,"org.springframework.cloud.gateway.filter.ForwardPathFilter@6bcae9":0,"org.springframework.cloud.gateway.filter.RemoveCachedBodyFilter@3ebc955b":-2147483648,"org.springframework.cloud.gateway.filter.WebsocketRoutingFilter@5aa781f2":2147483646,"org.springframework.cloud.gateway.filter.LoadBalancerClientFilter@25974207":10100,"org.springframework.cloud.gateway.filter.RouteToRequestUrlFilter@21a46ff1":10000,"org.springframework.cloud.gateway.filter.ForwardRoutingFilter@11b5f4e2":2147483647}

返回结果包含已就绪的global filters的详细信息(如 org.springframework.cloud.gateway.filter.LoadBalancerClientFilter@25974207。对于每个global filters，返回结果字符串对应过滤器链中的相应顺序。

2.检索所有的路由【 global filters 】

curl -X GET http://localhost:9001/actuator/gateway/routefilters

返回结果如下：

{"[RequestSizeGatewayFilterFactory@43ecfeb5 configClass = RequestSizeGatewayFilterFactory.RequestSizeConfig]":null,"[SetRequestHeaderGatewayFilterFactory@5a058be5 configClass = AbstractNameValueGatewayFilterFactory.NameValueConfig]":null,"[RedirectToGatewayFilterFactory@3becc950 configClass = RedirectToGatewayFilterFactory.Config]":null,"[RewritePathGatewayFilterFactory@f557c37 configClass = RewritePathGatewayFilterFactory.Config]":null,"[RetryGatewayFilterFactory@1a01d7f0 configClass = RetryGatewayFilterFactory.RetryConfig]":null,"[RemoveResponseHeaderGatewayFilterFactory@52ae997b configClass = AbstractGatewayFilterFactory.NameConfig]":null,"[StripPrefixGatewayFilterFactory@52ea0269 configClass = StripPrefixGatewayFilterFactory.Config]":null,"[RequestHeaderSizeGatewayFilterFactory@51efb731 configClass = RequestHeaderSizeGatewayFilterFactory.Config]":null,"[SetResponseHeaderGatewayFilterFactory@4eaf7902 configClass = AbstractNameValueGatewayFilterFactory.NameValueConfig]":null,"[RemoveRequestParameterGatewayFilterFactory@79476a4e configClass = AbstractGatewayFilterFactory.NameConfig]":null,"[SetStatusGatewayFilterFactory@7061622 configClass = SetStatusGatewayFilterFactory.Config]":null,"[ModifyRequestBodyGatewayFilterFactory@60f21960 configClass = ModifyRequestBodyGatewayFilterFactory.Config]":null,"[AddResponseHeaderGatewayFilterFactory@9b23822 configClass = AbstractNameValueGatewayFilterFactory.NameValueConfig]":null,"[AddRequestParameterGatewayFilterFactory@25c2a9e3 configClass = AbstractNameValueGatewayFilterFactory.NameValueConfig]":null,"[RewriteLocationResponseHeaderGatewayFilterFactory@71aaf151 configClass = RewriteLocationResponseHeaderGatewayFilterFactory.Config]":null,"[DedupeResponseHeaderGatewayFilterFactory@6a6c7f42 configClass = DedupeResponseHeaderGatewayFilterFactory.Config]":null,"[SecureHeadersGatewayFilterFactory@7e15f4d4 configClass = Object]":null,"[RemoveRequestHeaderGatewayFilterFactory@6b9fdbc6 configClass = AbstractGatewayFilterFactory.NameConfig]":null,"[SaveSessionGatewayFilterFactory@32d418a9 configClass = Object]":null,"[AddRequestHeaderGatewayFilterFactory@5e26f1ed configClass = AbstractNameValueGatewayFilterFactory.NameValueConfig]":null,"[SetPathGatewayFilterFactory@5856dbe4 configClass = SetPathGatewayFilterFactory.Config]":null,"[RequestHeaderToRequestUriGatewayFilterFactory@746c411c configClass = AbstractGatewayFilterFactory.NameConfig]":null,"[RewriteResponseHeaderGatewayFilterFactory@20c812c8 configClass = RewriteResponseHeaderGatewayFilterFactory.Config]":null,"[MapRequestHeaderGatewayFilterFactory@39666e42 configClass = MapRequestHeaderGatewayFilterFactory.Config]":null,"[ModifyResponseBodyGatewayFilterFactory@5a515e5d configClass = ModifyResponseBodyGatewayFilterFactory.Config]":null,"[PrefixPathGatewayFilterFactory@423a0e1d configClass = PrefixPathGatewayFilterFactory.Config]":null,"[PreserveHostHeaderGatewayFilterFactory@32f32623 configClass = Object]":null}

返回结果包含应用于所有路由的GatewayFilter的详细信息。显示每个工厂提供字符串格式的相应对象（例如， [PreserveHostHeaderGatewayFilterFactory@32f32623 configClass = Object]）。请注意，null值是由于endpoint controller实现不完整造成的，因为它尝试在filter chain中设置对象的顺序，这不适用于GatewayFilter工厂对象。

3.清除路由的缓存

curl -X POST http://localhost:9001/actuator/gateway/refresh

没有返回值，只有200的状态码

4.检测网关中定义的路由

curl -X GET http://localhost:9001/actuator/gateway/routes

返回结果如下

[{"predicate":"Paths: [/sys/**], match trailing slash: true","route_id":"dyzh-demo-service","filters":[],"uri":"lb://dyzh-demo-service","order":0}]

结果中包含网关中所有定义的路由信息

5.获取单个路由信息

curl -X GET http://localhost:9001/actuator/gateway/routes/{id}

返回结果如下：

{"predicate":"Paths: [/sys/**], match trailing slash: true","route_id":"dyzh-demo-service","filters":[],"uri":"lb://dyzh-demo-service","order":0}

6. 创建一个路由

curl -X POST
http://localhost:9001/actuator/gateway/routes/test
-H ‘Content-Type: application/json’
-d ‘{
“id”:“dyzh-back-server”,
“uri”:“lb//dyzh-back-server”
}’

请求成功返回201的状态码

7.删除一个路由

curl -X DELETE http://localhost:9001/actuator/gateway/routes/dyzh-demo-service

3.跨域拦截

spring:cloud:gateway:globalcors:corsConfigurations:
          '[/**]':allowedOrigins:"https://domain"allowedMethods:- GETallowHeaders:- Content-Type

4.过滤器 GateWayFilter

Spring Cloud Gateway的filte只有两个：“pre”和“post”：

• pre:这种过滤器在请求被路由之前调用。可以利用这个过滤器实现身份验证、在集群中选择请求的微服务、记录调试的信息。

• post：这种过滤器在路由到服务器之后执行。这种过滤器可用来为响应添加HTTP Header、统计信息和指标、响应从微服务发送给客户端等。

Spring Cloud gateway的filter分为两种：GatewayFilter和Globalfilter。GlobalFilter会应用到所有的路由上，而Gatewayfilter将应用到单个路由或者一个分组的路由上。

如果要自定义一个GatewayFilter，需要实现GatewayFilterFactory。下面是一个你需要集成的抽象类AbstractGatewayFilterFactory。

PreGatewayFilterFactory.java.

publicclassPreGatewayFilterFactoryextendsAbstractGatewayFilterFactory<PreGatewayFilterFactory.Config>{publicPreGatewayFilterFactory(){super(Config.class);}@Overridepublic GatewayFilterapply(Config config){// grab configuration from Config objectreturn(exchange, chain)->{//If you want to build a "pre" filter you need to manipulate the//request before calling chain.filter
            ServerHttpRequest.Builder builder= exchange.getRequest().mutate();//use builder to manipulate the requestreturn chain.filter(exchange.mutate().request(request).build());};}publicstaticclassConfig{//Put the configuration properties for your filter here}}

PostGatewayFilterFactory.java.

publicclassPostGatewayFilterFactoryextendsAbstractGatewayFilterFactory<PostGatewayFilterFactory.Config>{publicPostGatewayFilterFactory(){super(Config.class);}@Overridepublic GatewayFilterapply(Config config){// grab configuration from Config objectreturn(exchange, chain)->{return chain.filter(exchange).then(Mono.fromRunnable(()->{
                ServerHttpResponse response= exchange.getResponse();//Manipulate the response in some way}));};}publicstaticclassConfig{//Put the configuration properties for your filter here}}

5.全局过滤器GlobalFilter

Spring Cloud Gateway根据作用范围分为GatewayFilter和GlobalFilter，二者区别如下：

GatewayFilter : 需要通过spring.cloud.routes.filters 配置在具体路由下，只作用在当前路由上或通过spring.cloud.default-filters配置在全局，作用在所有路由上。

当请求与路由匹配时，过滤Web处理程序会将的所有实例GlobalFilter和所有特定GatewayFilter于路由的实例添加到过滤器链中。该组合的过滤器链按org.springframework.core.Ordered接口排序，您可以通过实现该getOrder()方法进行设置。

ExampleConfiguration.java

@Beanpublic GlobalFiltercustomFilter(){returnnewCustomGlobalFilter();}publicclassCustomGlobalFilterimplementsGlobalFilter, Ordered{@Overridepublic Mono<Void>filter(ServerWebExchange exchange, GatewayFilterChain chain){
        log.info("custom global filter");return chain.filter(exchange);}@OverridepublicintgetOrder(){return-1;}}

6.http超时配置

connect-timeout必须以毫秒为单位指定。 response-timeout必须指定为java.time.Duration

• 全局http超时示例

spring:cloud:gateway:httpclient:connect-timeout:1000response-timeout: 5s

• 要配置每个路由超时：
  connect-timeout必须以毫秒为单位指定。
  response-timeout必须以毫秒为单位指定

-id: per_route_timeoutsuri: https://example.orgpredicates:-name: Pathargs:pattern: /delay/{timeout}metadata:response-timeout:200connect-timeout:200