前言

本文采用Spring cloud本文為2.1.8RELEASE，version=Greenwich.SR3

本文基于前兩篇文章eureka-server、eureka-client轻猖、eureka-ribbon和eureka-feign的實(shí)現(xiàn)强岸。
參考

• eureka-server
• eureka-client
• eureka-ribbon
• eureka-feign

概念

Spring Cloud Gateway是Spring Cloud的一個(gè)新項(xiàng)目，該項(xiàng)目是基于Spring5.0，Sprint Boot2.0和Project Reactor等技術(shù)開發(fā)的網(wǎng)關(guān)，它的目的是在微服務(wù)架構(gòu)中提供一種簡單有效的統(tǒng)一api路由管理方式。
Spring Cloud Gateway目標(biāo)是要替代Netflix Zuul竟宋，其不僅提供統(tǒng)一的路由管理方式，還提供一套基于Fliter鏈的方式的網(wǎng)關(guān)其他功能形纺，比如：限流丘侠、埋點(diǎn)、安全監(jiān)控等逐样。

名稱術(shù)語

• Route(路由)：網(wǎng)關(guān)的基本模塊蜗字，它有一個(gè)id打肝、一個(gè)目標(biāo)uri、一組斷言和一組過濾器組成挪捕，如果斷言為真粗梭，則路由匹配。
• Predicate(斷言)：是一個(gè)java8的Predicate级零。輸入類型是一個(gè)ServerWebExchange断医。可以使用它來匹配來自HTTP請求的內(nèi)容奏纪。
• Filter(過濾器)：是org.springframework.cloud.gateway.filter.GatewayFilter的實(shí)例鉴嗤，可以使用它來修改請求和響應(yīng)。

流程

image

客戶端向Spring Cloud Gateway發(fā)出請求序调。如果Gateway Handler映射確定請求與路由匹配醉锅，則將其發(fā)送到Gateway Web Handler。Gateway Web Handler通過特定于請求的篩選器鏈發(fā)送請求发绢。篩選器由虛線分隔的原因是硬耍，篩選器可以在發(fā)送代理請求之前或之后執(zhí)行邏輯。執(zhí)行所有“pre”篩選邏輯边酒，然后發(fā)出代理請求默垄。在發(fā)出代理請求后，執(zhí)行“POST”篩選邏輯甚纲。

創(chuàng)建Zuul工程

1.1 創(chuàng)建sping boot工程：spring-gateway

1.2 添加pom.xml相關(guān)依賴

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

1.3 application.yml添加配置信息

server:
  port: 8100
spring:
  application:
    name: spring-gateway
  cloud:
      gateway:
        discovery:
          locator:
            enabled: true
eureka:
  instance:
    hostname: eureka1.server.com
    lease-renewal-interval-in-seconds: 5
    lease-expiration-duration-in-seconds: 10
  client:
    service-url:
      defaultZone: http://eureka1.server.com:8701/eureka/,http://eureka2.server.com:8702/eureka/,http://eureka3.server.com:8703/eureka/

Spring.cloud.gateway.discovery.locator.enabled:true 這里先簡單使用了默認(rèn)的創(chuàng)建路由規(guī)則,自動(dòng)根據(jù)serviceid創(chuàng)建路由的功能

1.4 啟動(dòng)類SpringGatewayApplication說明

前幾片文章中都在對應(yīng)的啟動(dòng)類中增加了@EnableEurekaClient或@EnableDiscoveryClient注解，今天看文檔突然發(fā)現(xiàn)朦前，不用加@Enable*注解也可以自動(dòng)添加到注冊中心介杆，是因?yàn)樵赟pring Cloud Edgware版本之后，只要加上相關(guān)的依賴韭寸，并進(jìn)行相應(yīng)的配置就可以將服務(wù)自動(dòng)注冊到服務(wù)發(fā)現(xiàn)組件上春哨。

1.5 啟動(dòng)相關(guān)服務(wù)

按順序啟動(dòng)eureka-server、eureka-client恩伺、eureka-ribbon赴背、spring-gateway服務(wù)。
打開瀏覽器晶渠，先去eureka-server服務(wù)中心看一下服務(wù)是否正常啟動(dòng)凰荚，如下如：

image

image

因?yàn)槲覀儾庞玫氖亲詣?dòng)配置路由便瑟，所有這里url上的服務(wù)名稱要全部大寫，就是和服務(wù)注冊中心保存一致番川。
這里我可以看一下spring-gate的啟動(dòng)日志到涂，自動(dòng)路由名稱全部是大寫脊框。（個(gè)人覺得這里設(shè)計(jì)的不是很好）。

2019-10-12 16:40:35.870  INFO 97725 --- [ctor-http-nio-2] c.netflix.config.ChainedDynamicProperty  : Flipping property: SPRING-GATEWAY.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-12 16:40:35.890  INFO 97725 --- [ctor-http-nio-2] c.n.u.concurrent.ShutdownEnabledTimer    : Shutdown hook installed for: NFLoadBalancer-PingTimer-SPRING-GATEWAY
2019-10-12 16:40:35.890  INFO 97725 --- [ctor-http-nio-2] c.netflix.loadbalancer.BaseLoadBalancer  : Client: SPRING-GATEWAY instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=SPRING-GATEWAY,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2019-10-12 16:40:35.895  INFO 97725 --- [ctor-http-nio-2] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2019-10-12 16:40:35.910  INFO 97725 --- [ctor-http-nio-2] c.netflix.config.ChainedDynamicProperty  : Flipping property: SPRING-GATEWAY.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-12 16:40:35.911  INFO 97725 --- [ctor-http-nio-2] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client SPRING-GATEWAY initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=SPRING-GATEWAY,current list of Servers=[eureka1.server.com:8100],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone;   Instance count:1;   Active connections count: 0;    Circuit breaker tripped count: 0;   Active connections per server: 0.0;]
},Server stats: [[Server:eureka1.server.com:8100;   Zone:defaultZone;   Total Requests:0;   Successive connection failure:0;    Total blackout seconds:0;   Last connection made:Thu Jan 01 08:00:00 CST 1970;  First connection made: Thu Jan 01 08:00:00 CST 1970;    Active Connections:0;   total failure count in last (1000) msecs:0; average resp time:0.0;  90 percentile resp time:0.0;    95 percentile resp time:0.0;    min resp time:0.0;  max resp time:0.0;  stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@3b80e99c
2019-10-12 16:40:36.008  INFO 97725 --- [tor-http-nio-10] c.netflix.config.ChainedDynamicProperty  : Flipping property: EUREKA-RIBBON.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-12 16:40:36.009  INFO 97725 --- [tor-http-nio-10] c.n.u.concurrent.ShutdownEnabledTimer    : Shutdown hook installed for: NFLoadBalancer-PingTimer-EUREKA-RIBBON
2019-10-12 16:40:36.010  INFO 97725 --- [tor-http-nio-10] c.netflix.loadbalancer.BaseLoadBalancer  : Client: EUREKA-RIBBON instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=EUREKA-RIBBON,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2019-10-12 16:40:36.011  INFO 97725 --- [tor-http-nio-10] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2019-10-12 16:40:36.012  INFO 97725 --- [tor-http-nio-10] c.netflix.config.ChainedDynamicProperty  : Flipping property: EUREKA-RIBBON.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-12 16:40:36.012  INFO 97725 --- [tor-http-nio-10] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client EUREKA-RIBBON initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=EUREKA-RIBBON,current list of Servers=[eureka1.server.com:8901],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone; Instance count:1;   Active connections count: 0;    Circuit breaker tripped count: 0;   Active connections per server: 0.0;]
},Server stats: [[Server:eureka1.server.com:8901;   Zone:defaultZone;   Total Requests:0;   Successive connection failure:0;    Total blackout seconds:0;   Last connection made:Thu Jan 01 08:00:00 CST 1970;  First connection made: Thu Jan 01 08:00:00 CST 1970;    Active Connections:0;   total failure count in last (1000) msecs:0; average resp time:0.0;  90 percentile resp time:0.0;    95 percentile resp time:0.0;    min resp time:0.0;  max resp time:0.0;  stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@19148ab

同樣的方式我可以請求eureka-feign践啄，結(jié)果如下：

image

至此基于服務(wù)發(fā)現(xiàn)的默認(rèn)路由規(guī)則就搭建完成浇雹。

1.6 自定義路由規(guī)則

1.6.1 修改application.yml配置

server:
  port: 8100
spring:
  application:
    name: spring-gateway
  cloud:
      gateway:
#        discovery:
#          locator:
#            enabled: true # 開啟通過服務(wù)中心的自動(dòng)根據(jù) serviceId 創(chuàng)建路由的功能
        routes:
          - id: ribbon-route
            uri: lb://EUREKA-RIBBON
            order: 0
            predicates:
              - Path=/ribbon/**
            filters:
              - StripPrefix=1 #去掉前綴，具體實(shí)現(xiàn)參考StripPrefixGatewayFilterFactory
              - AddResponseHeader=X-Response-Default-Foo, Default-Bar
          - id: feign-route
            uri: lb://EUREKA-FEIGN
            order: 0
            predicates:
              - Path=/feign/**
            filters:
              - StripPrefix=1
              - AddResponseHeader=X-Response-Default-Foo, Default-Bar

eureka:
  instance:
    hostname: eureka1.server.com
    lease-renewal-interval-in-seconds: 5
    lease-expiration-duration-in-seconds: 10
  client:
    service-url:
      defaultZone: http://eureka1.server.com:8701/eureka/,http://eureka2.server.com:8702/eureka/,http://eureka3.server.com:8703/eureka/

StripPrefix: 接受一個(gè)非負(fù)整數(shù)屿讽，對應(yīng)的具體實(shí)現(xiàn)是StripPrefixGatewayFilterFactory昭灵，做用是去掉前綴，整數(shù)對應(yīng)層數(shù)聂儒。在本例中訪問的/ribbon/sayHello虎锚，網(wǎng)關(guān)服務(wù)向后轉(zhuǎn)發(fā)請求的時(shí)候會(huì)去掉/ribbon，eureka-ribbon收到的請求是：/sayHello衩婚。eureka-feign同理窜护。

1.6.2 啟動(dòng)服務(wù)

訪問http://localhost:8100/ribbon/sayHello和http://localhost:8100/feign/feign/sayHello，如圖下圖顯示：

• ribbon:

image

• feign:

image

1.6.3 自定義Configuration

Spring Cloud Gateway同時(shí)支持java的流式api的路由定義非春，可以和application.yml配合使用柱徙。

package spring.cloud.demo.spring.gateway.config;

import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RoutesConfig {

    @Bean
    public RouteLocator routeLocator(RouteLocatorBuilder routeLocatorBuilder){
        return routeLocatorBuilder.routes().route(r -> r.path("/ribbon/**")
                .filters(f -> f.stripPrefix(1)
                        .addRequestHeader("X-Response-Default-Foo", "Default-Bar"))
                .uri("lb://EUREKA-RIBBON")
                .order(0)
                .id("ribbon-route")
        ).build();
    }
}

總結(jié)

本文簡單實(shí)現(xiàn)了Spring Cloud Gateway的默認(rèn)自動(dòng)路由和自定義路由的網(wǎng)關(guān)服務(wù)。后面會(huì)繼續(xù)更新Spring Cloud Gateway的其他功能奇昙，敬請期待护侮！

代碼地址

gitHub地址

<center><font color=red>《Srping Cloud 2.X小白教程》目錄</font></center>

• spring cloud 2.x版本 Eureka Server服務(wù)注冊中心教程
• spring cloud 2.x版本 Eureka Client服務(wù)提供者教程
• spring cloud 2.x版本 Ribbon服務(wù)發(fā)現(xiàn)教程(內(nèi)含集成Hystrix熔斷機(jī)制)
• spring cloud 2.x版本 Feign服務(wù)發(fā)現(xiàn)教程(內(nèi)含集成Hystrix熔斷機(jī)制)
• spring cloud 2.x版本 Zuul路由網(wǎng)關(guān)教程
• spring cloud 2.x版本 config分布式配置中心教程
• spring cloud 2.x版本 Hystrix Dashboard斷路器教程
• spring cloud 2.x版本 Gateway路由網(wǎng)關(guān)教程

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