Spring Cloud 学习 - Gateway新一代网关

Spring Cloud Gateway 新一代网关

Spring Cloud Gateway 是Spring Cloud的一个全新项目，基于Spring 5.0 + Spring Boot 2.x和Project Reactor等技术开发的网关，旨在为微服务架构提供一种有效的统一的API路由管理方式。

Spring Cloud Gateway作为Spring Cloud生态系统中的网关组件，目标是替代Zuul。由于Zuul2.x的多次跳票，为了提升网关的性能，Spring Cloud官方基于Spring WebFlux开发了非阻塞的网关组件Gateway，WebFlux框架底层使用了高性能的Reactor模式的非阻塞通信框架Netty。

引入依赖

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

因为要从注册中心对服务实例进行动态路由，这里加入了eureka-client的依赖，把gateway注册到eureka中。

服务发现

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

编写配置

事前先编写如下2个服务，并提供相应的接口，服务名称分别为cloud-provider、cloud-consumer

server:
  port: 8008
spring:
  application:
    name: cloud-gateway
  devtools:
    livereload:
      port: 35731 # 设置热部署插件端口，防止端口冲突导致热加载不生效
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true # 开启动态路由，不配置uri时默认访问路径：/serviceId/url, e.g. http://localhost:8008/cloud-provider/provider/xudc
          lower-case-service-id: true # 启用serviceId小写功能，默认是全部大写，e.g. CLOUD-PROVIDER,开启后：cloud-provider
      routes:
        - id: spring-cloud-provider # 指定路由id，可任意名称，唯一即可
          uri: lb://cloud-provider # lb表示负载均衡到<serviceId>
          predicates:
            - Path=/provider/**

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/

自定义全局过滤

@Component
public class CustomFilter implements GlobalFilter, Ordered {
    /**
     * 模拟用户登录过滤
     * 携带token参数则认为是授权的，未携带则未授权，拒绝访问
     * @param exchange
     * @param chain
     * @return
     */
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        String token = request.getQueryParams().getFirst("token");
        if (StringUtils.isEmpty(token)) {
            ServerHttpResponse response = exchange.getResponse();
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            byte[] bytes = "{\"status\": 401,\"message\": \"Unauthorized Request!请求未授权\"}".getBytes(StandardCharsets.UTF_8);
            DataBuffer buffer = response.bufferFactory().wrap(bytes);
            // 设置编码utf-8，否则浏览器中文可能会乱码
            response.getHeaders().add("content-type", "text/plain;charset=utf-8");
            // return exchange.getResponse().setComplete();
            return response.writeWith(Flux.just(buffer));
        }
        // 通过则放行
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}

测试

GET http://localhost:8008/provider/cindy

HTTP/1.1 401 Unauthorized
transfer-encoding: chunked
content-type: text/plain;charset=utf-8

{"status": 401,"message": "Unauthorized Request!请求未授权"}

GET http://localhost:8008/provider/cindy?token=qwerasd

HTTP/1.1 200 OK
Content-Type: text/plain;charset=UTF-8
Content-Length: 12

Hello, cindy

以上就是Spring Cloud Gateway的简单使用。
更多功能使用，请参阅官方文档: https://cloud.spring.io/spring-cloud-static/spring-cloud-gateway/2.2.2.RELEASE/reference/html/#gateway-starter

因个人能力有限，如果不足或错误之处，欢迎指正~