Spring Cloud Gateway 基础使用

迷南。 2021-11-17 10:31 202阅读 0赞

Spring Cloud Gateway是Spring Cloud官方推出的第二代网关框架，取代Zuul网关。网关作为流量的，在微服务系统中有着非常作用，网关常见的功能有路由转发、权限校验、限流控制等作用。

## 项目结构 ##

<table> 
 <thead> 
  <tr> 
   <th>项目</th> 
   <th>端口</th> 
   <th>描述</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>eureka-server</td> 
   <td>8761</td> 
   <td>服务的注册与发现</td> 
  </tr> 
  <tr> 
   <td>service-one</td> 
   <td>8081</td> 
   <td>服务</td> 
  </tr> 
  <tr> 
   <td>gateway-client</td> 
   <td>8080</td> 
   <td>网关 gateway</td> 
  </tr> 
 </tbody> 
</table>

## eureka-server ##

eureka-server项目非常简单 引入

<dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>

启动类里面

@EnableEurekaServer
    @SpringBootApplication
    public class EurekaServerApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(EurekaServerApplication.class, args);
        }
    }

配置文件

spring:
      application:
        name: eureka-server
    
    server:
      port: 8761
    eureka:
      instance:
        hostname: localhostname
      client:
        fetch-registry: false
        register-with-eureka: false
        service-url:
          defaultZone: http://localhost:8761/eureka/

## service-one 项目 ##

搭建非常简单，添加依赖

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

启动类里面

@EnableEurekaClient
    @SpringBootApplication
    public class ServiceOneApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ServiceOneApplication.class, args);
        }
    }

配置文件

spring:
      application:
        name: service-one
    server:
      port: 8081
    
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/

创建类控制器 UserController，[http://localhost:8081/user/who][http_localhost_8081_user_who]

@RequestMapping("/user")
    @RestController
    public class UserController {
    
        @RequestMapping("who")
        public String who() {
            return "my name is liangwang";
        }
    }

创建类控制器OrderController，[http://localhost:8081/order/info][http_localhost_8081_order_info]

@RequestMapping("/order")
    @RestController
    public class OrderController {
    
        @RequestMapping("/info")
        public String orderInfo() {
            return "order info date : " + new Date().toString();
        }
    }

## gateway-client项目 ##

使用的是Finchley.SR2版本的，其中已经包含了 `spring-boot-starter-webflux`  
添加依赖

<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>

使用RouteLocator的Bean进行路由转发，将请求进行处理，最后转发到目标的下游服务

> 上面的代码里是在访问[http://localhost:8080/order/][http_localhost_8080_order]**的时候，网关转发到[http://service-one:8081/order/][http_service-one_8081_order]**，service-one服务在eureka中有注册，最终是对应服务的ip:port

使用配置文件  
application.yml

test:
      uri: lb://service-one
    spring:
      application:
        name: gateway-client
      cloud:
        gateway:
          routes:
          - id: route_service_one
            uri: ${test.uri} # uri以lb://开头（lb代表从注册中心获取服务），后面接的就是你需要转发到的服务名称
            predicates:
            - Path=/user/**
    
    server:
      port: 8080
    
    logging:
      level:
        org.springframework.cloud.gateway: TRACE
        org.springframework.http.server.reactive: DEBUG
        org.springframework.web.reactive: DEBUG
        reactor.ipc.netty: DEBUG
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/
      instance:
        prefer-ip-address: true

其中test.uri是我自定义的属性，uri以lb://开头（lb代表从注册中心获取服务），后面接的就是你需要转发到的服务名称，按照上面的配置是[http://localhost:8080/usr/\*\*][http_localhost_8080_usr] => [http://service-one:8081/user/\*\*][http_service-one_8081_user] 到此项目搭建完成，接下来测试了，依次启动eureka-server、service-one、gateway-client  
访问

*  [http://localhost:8080/user/who][http_localhost_8080_user_who]
 *  [http://localhost:8080/order/info][http_localhost_8080_order_info]

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTk1OWU1NWY2YTliN2EzYzEucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy85NDQvZm9ybWF0L3dlYnA][]

WX20181113-180248@2x.png

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTY3N2FjMzdlNmFlZGVmNmMucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy83MzYvZm9ybWF0L3dlYnA][]

WX20181113-180339@2x.png

### 不启用注册中心 ###

即使集成了eureka-client也不想使用注册中心服务，可以关闭

eureka.client.enabled=false

### StripPrefix属性的使用 ###

按照上面的配置，每一个路由只能对应一个控制器的转发，不够灵活，假如我想让userapi的请求都转到service-one服务，比如：

*  [http://localhost:8080/userapi/user/who][http_localhost_8080_userapi_user_who] => [http://localhost:8081/user/who][http_localhost_8081_user_who]
 *  [http://localhost:8080/userapi/order/info][http_localhost_8080_userapi_order_info] => [http://localhost:8081/order/info][http_localhost_8081_order_info]  
    在路由配置上增加 `StripPrefix=1`

修改完配置，重启gateway-client项目：

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTdmNDdkNjY1MDk4ZTg5MjAucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy84MzYvZm9ybWF0L3dlYnA][]

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTI2ZDA4YzUwZTZkMWU0YzQucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy83MjYvZm9ybWF0L3dlYnA][]

## 使用Hystrix ##

在gateway-client项目中引入依赖

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
            </dependency>

在spring cloud gateway中可以使用Hystrix。Hystrix是 spring cloud中一个服务熔断降级的组件，在微服务系统有着十分重要的作用。  
Hystrix是 spring cloud gateway中是以filter的形式使用的，代码如下：

@SpringBootApplication
    public class GatewayClientApplication {
    
        @Value("${test.uri}")
        private String uri;
    
        @Bean
        public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
            return builder.routes()
                    //basic proxy
                    .route(r -> r.path("/order/**")
                            .uri(uri)
                    )
                    .route(r -> r.path("/user/**")
                            .filters(f -> f
                                    .hystrix(config -> config
                                            .setName("myserviceOne")
                                            .setFallbackUri("forward:/user/fallback")))
                            .uri(uri)).build();
        }
    
        public static void main(String[] args) {
            SpringApplication.run(GatewayClientApplication.class, args);
        }
    }

上面代码中添加了一个路由并配置了hystrix的fallbackUri，新添加一个FallBackController控制器

@RestController
    public class FallBackController {
        @RequestMapping("/user/fallback")
        public Mono<String> fallback() {
            return Mono.just("service error, jump fallback");
        }
    }

重启gateway-client项目，并关闭service-one服务，在浏览器访问 [http://localhost:8080/user/who][http_localhost_8080_user_who]

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LWUzZjFlZDUxMTYyNWU2OGIucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy82NjAvZm9ybWF0L3dlYnA][]

**使用yml配置Hystrix**

spring:
      application:
        name: gateway-client
      cloud:
        gateway:
          routes:
          - id: route_service_one
            uri: ${test.uri} # uri以lb://开头（lb代表从注册中心获取服务），后面接的就是你需要转发到的服务名称
            predicates:
            - Path=/userapi/**
            filters:
            - StripPrefix=1 # 表示在转发时去掉userapi
    
          - id: userapi2_route
            uri: ${test.uri}
            predicates:
            - Path=/userapi2/**
            filters:
            - StripPrefix=1
            - name: Hystrix
              args:
                name: myfallbackcmd
                fallbackUri: forward:/user/fallback

在配置中增加了一个新的路由userapi2\_route，还配置了Hystrix，当发生错误时会转发到fallbackUri，测试访问 [http://localhost:8080/userapi2/order/info][http_localhost_8080_userapi2_order_info]

![aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LWU2ZTk4MmZjMTljODUxMjQucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy83NjIvZm9ybWF0L3dlYnA][]

[http_localhost_8081_user_who]: http://localhost:8081/user/who
[http_localhost_8081_order_info]: http://localhost:8081/order/info
[http_localhost_8080_order]: http://localhost:8080/order/
[http_service-one_8081_order]: http://service-one:8081/order/
[http_localhost_8080_usr]: http://localhost:8080/usr/**
[http_service-one_8081_user]: http://service-one:8081/user/**
[http_localhost_8080_user_who]: http://localhost:8080/user/who
[http_localhost_8080_order_info]: http://localhost:8080/order/info
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[aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTY3N2FjMzdlNmFlZGVmNmMucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy83MzYvZm9ybWF0L3dlYnA]: /images/20211116/6b5fa570d3c0473a95cbe18b6a490fe4.png
[http_localhost_8080_userapi_user_who]: http://localhost:8080/userapi/user/who
[http_localhost_8080_userapi_order_info]: http://localhost:8080/userapi/order/info
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[aHR0cHM6Ly91cGxvYWQtaW1hZ2VzLmppYW5zaHUuaW8vdXBsb2FkX2ltYWdlcy8yMTUxOTA1LTI2ZDA4YzUwZTZkMWU0YzQucG5nP2ltYWdlTW9ncjIvYXV0by1vcmllbnQvc3RyaXAlN0NpbWFnZVZpZXcyLzIvdy83MjYvZm9ybWF0L3dlYnA]: /images/20211116/bbde26460cba4cb6911cd3d978dfbadc.png
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[http_localhost_8080_userapi2_order_info]: http://localhost:8080/userapi2/order/info
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