Global Filter

Global Filter

Custom Filter를 이용하여 상황에 맞는 필터를 걸어주었다면 Global Filter 를 이용해서 모든 필터에 적용되는 전역 필터를 생성해 줄 수 있다.

• Global Filter, Custom Filter 실행 순서
  1. Global Filter start
  2. Custom Filter start
  3. Custom FIlter end
  4. Global Filter end
• Global Filter 가 먼저 실행되고 그 사이에 Custom Filter가 먼저 실행된다.

Global Filter 생성 실습

1. GlobalFilter class 생성

   기존의 Custom Filter를 생성했을때와 동일하게 AbstractGatewayFilterFactory를 상속받아 구현한다.

   @Slf4j
   @Component
   public class GlobalFilter extends AbstractGatewayFilterFactory<GlobalFilter.Config> {
       public GlobalFilter() {
           super(Config.class);
       }
   
       @Override
       public GatewayFilter apply(Config config) {
           // Global Pre Filter
           return (exchange, chain) -> {
               ServerHttpRequest request = exchange.getRequest();
               ServerHttpResponse response = exchange.getResponse();
   
               log.info("Global Filter baseMessage: {}", config.getBaseMessage());
   
               if (config.isPreLogger()) {
                   log.info("Global Filter Start: request id -> {}", request.getId());
               }
   
               // Custom Post Filter
               return chain.filter(exchange).then(Mono.fromRunnable(() -> {
                   if (config.isPostLogger()) {
                       log.info("Global Filter End: response code -> {}", response.getStatusCode());
                   }
               }));
           };
       }
   
       @Data
       public static class Config {
           private String baseMessage;
           private boolean preLogger;
           private boolean postLogger;
       }
   }

2. application.yml에 Global Filter 등록 및 변수 설정

   spring:
     application:
       name: api-gateway-service
     cloud:
       gateway:
         default-filters:
           - name: GlobalFilter
             args:
               baseMessage: String Cloud Gateway GlobalFilter
               preLogger: true
               postLogger: true
         routes:
           - id: first-service
             uri: http://localhost:8081/
             predicates:
               - Path=/first-service/**
             filters:
               - AddRequestHeader=first-request, first-request-header2
               - AddResponseHeader=first-response, first-response-header2
               - CustomFilter
           - id: second-service
             uri: http://localhost:8082/
             predicates:
               - Path=/second-service/**
             filters:
               - AddRequestHeader=second-request, second-request-header2
               - AddResponseHeader=second-response, second-response-header2
               - CustomFilter

   • default-filters에 GlobalFilter를 등록
   • args에 GlobalFilter.Config 변수를 설정

3. GlobalFilter 테스트

   http://localhost:8000/first-service/check

   2024-07-11T20:56:23.526+09:00 : Global Filter baseMessage: String Cloud Gateway GlobalFilter
   2024-07-11T20:56:23.526+09:00 : Global Filter Start: request id -> 1084042e-4
   2024-07-11T20:56:23.528+09:00 : Custom PRE filter: request id -> 1084042e-4
   2024-07-11T20:56:23.534+09:00 : Custom POST filter: response code -> 200 OK
   2024-07-11T20:56:23.535+09:00 : Global Filter End: response code -> 200 OK

   • Global Filter가 먼저 실행되고 중간에 Custom Filter가 실행되는 것을 확인
   • application.yml의 변수가 제대로 할당된 것을 확인