Gateway服务限流配置

àì夳堔傛蜴生んèń 2023-10-10 17:43 76阅读 0赞

## Gateway服务限流配置 ##

### 背景 ###

限流作用就不说了，往往都是防止一些恶意请求，无限制请求接口导致服务处理时间过长，继而导致响应延迟，服务阻塞等等，所以会对高频率的一些接口添加限流这样的功能。

刚好gateway刚好自带了服务限流功能，所以我们就用gateway实现此功能。

#### 编写一个限流规则 ####

1、添加RateLimiterConfig配置文件

package org.example.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import reactor.core.publisher.Mono;
    
    @Configuration
    @Slf4j
    public class RateLimiterConfig {
        
    
        RateLimiterConfig(){
        
            log.info("限流配置加载");
        }
    
        /**
         * 根据用户ip限流规则
         * @return
         */
        @Primary
        @Bean(value = "remoteAddrKeyResolver")
        public KeyResolver remoteAddrKeyResolver(){
        
            return exchange -> {
        
                String hostAddress=exchange.getRequest()
                        .getRemoteAddress()
                        .getAddress()
                        .getHostAddress();
                System.out.println(hostAddress);
                return Mono.just(hostAddress);
            };
        }
        /**
         * 根据Path限流
         *
         * @return key
         */
        @Bean(value = "pathKeyResolver")
        public KeyResolver pathKeyResolver() {
        
            return exchange -> Mono.just(exchange.getRequest().getPath().toString());
        }
    
    
    }

2、编写配置文件让配置文件扫描刚刚添加的bean

spring:
      cloud:
        gateway:
          discovery:
            locator:
              enabled: false
          routes:
            # 商品模块
            - id: Commodity #路由id,唯一
              uri: lb://Commodity
              predicates:
                - Path=/commodity/** #以city开头的请求都负载到consumer服务
              filters:
                - name: RequestRateLimiter
                  args:
                    # 令牌桶每秒填充平均速率
                    redis-rate-limiter.replenishRate: 5
                    # 令牌桶的上限
                    redis-rate-limiter.burstCapacity: 10
                    key-resolver: "#{@remoteAddrKeyResolver}"

注意：

*  那个服务需要限流就在那个服务下加入filter的配置即可，如果不需要限流则不需要添加
 *  name字段必须为`RequestRateLimiter`
 *  key-resolver参数对应注入到Spring中Bean的名称。

但是我们发现请求后如果用户请求接口到达上限制返回的是1，这让前端不知道是后端发生了什么异常，这并不符合我们的设计要求。

所以服务升级

\\|/

### 自定义返回信息配置类 ###

添加GatewayRequestRateLimiterGatewayFilterFactory自定义异常类

package org.example.config;
    
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.cloud.gateway.filter.GatewayFilter;
    import org.springframework.cloud.gateway.filter.factory.RequestRateLimiterGatewayFilterFactory;
    import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
    import org.springframework.cloud.gateway.filter.ratelimit.RateLimiter;
    import org.springframework.cloud.gateway.route.Route;
    import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
    import org.springframework.core.io.buffer.DataBuffer;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.server.reactive.ServerHttpResponse;
    import org.springframework.stereotype.Component;
    import reactor.core.publisher.Mono;
    
    import java.nio.charset.StandardCharsets;
    import java.util.Map;
    
    /***
     * @限流自定义
     * @author CMS
     */
    @Slf4j
    @Component
    public class GatewayRequestRateLimiterGatewayFilterFactory extends RequestRateLimiterGatewayFilterFactory {
        
    
    
      private final RateLimiter defaultRateLimiter;
    
      private final KeyResolver defaultKeyResolver;
    
      public GatewayRequestRateLimiterGatewayFilterFactory(RateLimiter defaultRateLimiter, KeyResolver defaultKeyResolver) {
        
        super(defaultRateLimiter, defaultKeyResolver);
        this.defaultRateLimiter = defaultRateLimiter;
        this.defaultKeyResolver = defaultKeyResolver;
        log.info("限流自定义返回加载");
      }
    
      @Override
      public GatewayFilter apply(Config config) {
        
        KeyResolver resolver = getOrDefault(config.getKeyResolver(), defaultKeyResolver);
        RateLimiter<Object> limiter = getOrDefault(config.getRateLimiter(), defaultRateLimiter);
        return (exchange, chain) -> resolver.resolve(exchange).flatMap(key -> {
        
          String routeId = config.getRouteId();
          if (routeId == null) {
        
            Route route = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
            routeId = route.getId();
          }
          String finalRouteId = routeId;
          return limiter.isAllowed(routeId, key).flatMap(response -> {
        
            for (Map.Entry<String, String> header : response.getHeaders().entrySet()) {
        
              exchange.getResponse().getHeaders().add(header.getKey(), header.getValue());
            }
            if (response.isAllowed()) {
        
              return chain.filter(exchange);
            }
            log.warn("已限流: {}", finalRouteId);
            ServerHttpResponse httpResponse = exchange.getResponse();
            //修改code为500
            httpResponse.setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);
            if (!httpResponse.getHeaders().containsKey("Content-Type")) {
        
              httpResponse.getHeaders().add("Content-Type", "application/json");
            }
            //此处无法触发全局异常处理，手动返回
            DataBuffer buffer = httpResponse.bufferFactory().wrap(("{\n"
                + "  \"code\": \"1414\","
                + "  \"message\": \"服务器限流\","
                + "  \"data\": \"Server throttling\","
                + "  \"success\": false"
                + "}").getBytes(StandardCharsets.UTF_8));
            return httpResponse.writeWith(Mono.just(buffer));
          });
        });
      }
    
      private <T> T getOrDefault(T configValue, T defaultValue) {
        
        return (configValue != null) ? configValue : defaultValue;
      }
    }

接着修改我们的配置文件

spring:
      cloud:
        gateway:
          discovery:
            locator:
              enabled: false
          routes:
            # 商品模块
            - id: Commodity #路由id,唯一
              uri: lb://Commodity
              predicates:
                - Path=/commodity/** #以city开头的请求都负载到consumer服务
              filters:
                - name: GatewayRequestRateLimiter  #修改此处，改成我们自定义的返回信息配置类
                  args:
                    # 令牌桶每秒填充平均速率
                    redis-rate-limiter.replenishRate: 5
                    # 令牌桶的上限
                    redis-rate-limiter.burstCapacity: 10
                    key-resolver: "#{@remoteAddrKeyResolver}"

最后我们的限流工作就ok了。

![image-20230515211619195][]

> 温馨小提示：gateway默认的限流规则只能有一个，如果需要配置两个可以参考–>[(3条消息) Spring Cloud Gateway 限流适配多规则的解决方案\_Suremotoo丶小小书童的博客-CSDN博客][3_ Spring Cloud Gateway _Suremotoo_-CSDN]的文章。

[image-20230515211619195]: https://img-blog.csdnimg.cn/img_convert/7d2d4f94b849bae99f537a2494a54d9d.png
[3_ Spring Cloud Gateway _Suremotoo_-CSDN]: https://blog.csdn.net/Suremotoo/article/details/118640225