Gateway 笔记

gateway：

1. 导入依赖

    
        
            org.springframework.cloud
            spring-cloud-dependencies
            Hoxton.SR3
            pom
            import
        
        
            com.alibaba.cloud
            spring-cloud-alibaba-dependencies
            2.2.1.RELEASE
            pom
            import
        
    



    
        com.alibaba.cloud
        spring-cloud-starter-alibaba-nacos-discovery
    
    
        com.alibaba.cloud
        spring-cloud-starter-alibaba-nacos-config
    
    
        org.springframework.cloud
        spring-cloud-starter-gateway
    

2. 配yml

server:
  port: 8989

spring:
  application:
    name: gateway
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
      config:
        server-addr: localhost:8848
        file-extension: yaml
    gateway:
      discovery:
        locator:
          enabled: true # 开启微服务名字转发
      routes:
        - id: payment
          uri: lb://provider-payment
          predicates:
            - Path=/payment/**
#          filters:
#            - name: RequestRateLimiter
#              args:
#                redis-rate-limiter.replenishRate: 1
#                redis-rate-limiter.burstCapacity: 2
#                key-resolver: "#{@ipKeyResolver}"
        - id: consumer
          uri: lb://consumer-order
          predicates:
            - Path=/order/**
          filters:
            - StripPrefix=1 # 截取一段前缀

Noting：filters 和 predicates 都有s ，少写会失败

3. 启动类上加上注册与发现：@EnableDiscoveryClient

4. 全局filter。因为使用的是Webflux，所以用exchange替代了request和respond。chain代表链条，来回都会经过。order 表示优先级，数字越小优先级越高。返回Mono等同于void，无实际含义。

@Configuration
@Slf4j
public class ParamConfiguration implements GlobalFilter, Ordered {

    @Override
    public Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        log.info("custom global filter");
        System.out.println("exchange.getRequest().getPath() = " + exchange.getRequest().getPath());
        return chain.filter(exchange);
    }

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