SpringCloud Gateway RequestRateLimiter Sınıfı - API Rate Limiter İçin Kullanılır

Giriş

Şu satırı dahil ederiz

import org.springframework.cloud.gateway.filter.ratelimit.RateLimiter;
import org.springframework.cloud.gateway.filter.ratelimit.RedisRateLimiter;

Maven

Şöyle yaparız. RequestRateLimiter altta Redis kullanır. Dolayısıyla data-redis gerekir.

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

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifatId>spring-boot-starter-data-redis-reactive</artifactId>
</dependency>

Açıklaması şöyle

RequestRateLimiter is one of the many gateway filters offered by SCG. The implementation determines whether a request is allowed to proceed or has exceeded its limit. ...

the gateway comes with one that uses a user’s Principal name. A secured gateway is needed to resolve a user’s principal name, but you have the option to implement the KeyResolver interface to instead resolve a different key from the ServerWebExchange. 

You can point to a custom KeyResolver bean (for example, named customKeyResolver) in the configuration by using a SPEL #{@customKeyResolver} expression. 

RequestRateLimiter sınfı RequestRateLimiterGatewayFilterFactory tarafından yaratılır

Açıklaması şöyle

The provided Redis implementation lets you define the request rate at which users can make calls within a certain time period. It also makes it possible to accommodate sporadic demands while constrained by the defined consumption rate. For example, a configuration can define a replenish rate of 500 requests per second by setting the redis-rate-limiter.replenishRate=500 property and a burst capacity of 1000 request per second by setting the redis-rate-limiter.burstCapacity=1000 property. Doing so limits consumption to 500 requests every second. If a burst in the number of requests occurs, only 1,000 requests are allowed. However, because 1,000 requests are a quota of 2 seconds, the gateway would not route requests for the next second. The configuration also lets you define how many tokens a request would cost by setting the property redis-rate-limiter.requestedTokens property. Typically, it is set to 1.

To use a gateway with a request limiting feature, it needs to be configured with the RequestRateLimiter gateway filter. 

Yani şöyle yaparız

spring:
  cloud:
    gateway:
      routes:
        - id: route1
          uri: http://localhost:8081
          predicates:
            - Path=/backend
          filters:
          - name: RequestRateLimiter
            args:
              redis-rate-limiter.replenishRate: 500
              redis-rate-limiter.burstCapacity: 1000
              redis-rate-limiter.requestedTokens: 1

Açıklaması şöyle

burstCapacity, the total capacity of the token bucket.

replenishRate, the average rate at which the token bucket is filled per second.

KeyResolver  Arayüzü

Şu satırı dahil ederiz

import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;

Eğer KeyResolver kullanmak istersek şöyle yaparız

spring:
  cloud:
    gateway:
      routes:
        - id: route1
          uri: http://localhost:8081
          predicates:
            - Path=/backend
          filters:
          - name: RequestRateLimiter
            args:
              rate-limiter: "#{customRateLimiter}"
              key-resolver: "#{customKeyResolver}"

@Bean
public KeyResolver customKeyResolver {
  return exchange -> ....  // returns a Mono of String
}

Çok detaylı bir örnek burada

Örnek

Şöyle yaparız

server:
  port: 8081
spring:
  cloud:
    gateway:
      routes:
      - id: limit_route
        uri: http://httpbin.org:80/get
        predicates:
        - After=2017-01-20T17:42:47.789-07:00[America/Denver]
        filters:
        - name: RequestRateLimiter
          args:
            key-resolver: '#{@hostAddrKeyResolver}'
            redis-rate-limiter.replenishRate: 1
            redis-rate-limiter.burstCapacity: 3
  application:
    name: gateway-limiter
  redis:
    host: localhost
    port: 6379
    database: 0

Açıklaması şöyle

key-resolver, the name of the bean object of the resolver for the throttled key. It uses SpEL expressions to get bean objects from the Spring container based on #{@beanName}.

Hostname özelliğine göre sınırlamak için şöyle yaparız

public class HostAddrKeyResolver implements KeyResolver {

  @Override
  public Mono<String> resolve(ServerWebExchange exchange) {
    return Mono.just(exchange.getRequest().getRemoteAddress()
      .getAddress().getHostAddress());
  }

}

@Bean
public HostAddrKeyResolver hostAddrKeyResolver() {
  return new HostAddrKeyResolver();
}

URI'ye göre sınırlamak için şöyle yaparız

public class UriKeyResolver  implements KeyResolver {

  @Override
  public Mono<String> resolve(ServerWebExchange exchange) {
    return Mono.just(exchange.getRequest().getURI().getPath());
  }
}

@Bean
public UriKeyResolver uriKeyResolver() {
  return new UriKeyResolver();
}

Örnek

Şöyle yaparız

import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
import org.springframework.web.server.ServerWebExchange;

import com.auth0.jwt.JWT;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import io.netty.util.internal.StringUtil;
import reactor.core.publisher.Mono;

public class CustomerKeyResolver implements KeyResolver {

  @Override
  public Mono<String> resolve(ServerWebExchange exchange) {
    String apiName = exchange.getRequest().getPath().toString();

    List<String> customerIds = exchange.getRequest().getHeaders().get("X-Customer-Id");
    if (customerIds != null && ...) {
      return Mono.just(customerIds.get(0) + StringUtil.COMMA + apiName);
    }

    List<String> authHeaders = exchange.getRequest().getHeaders().get("Authorization");
    if (authHeaders != null && ...) {
      ...
    }

    return Mono.just(StringUtil.EMPTY_STRING);
  }
}