MSA 공부 (Logging Filter) - 8

먼저 글 작성에 앞서 해당 시리즈는 Spring Cloud로 개발하는 마이크로서비스 애플리케이션(MSA) 강의를 참고하여 필요한 내용들을 정리한 것임을 밝힙니다.

Global Filter

• 글로벌 필터는 설정상 모든 필터중에 가장 처음과 마지막을 담당

• application.yml

  spring:
    application:
      name: apigateway-service
    cloud:
      gateway:
        default-filters:
          - name: GlobalFilter # default filter를 넣어줌으로써 모든 route에 적용
            args: # 해당 필터에 적용되는 arguments
              baseMessage: Spring Cloud Gateway Global Filter
              preLogger: true
              postLogger: true        

• GlobalFilter.java

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

Logging Filter

• 로그를 위한 필터

• LoggingFilter.java

  @Component
  @Slf4j
  public class LoggingFilter extends AbstractGatewayFilterFactory<LoggingFilter.Config> {
  
      public LoggingFilter() {
          super(Config.class);
      }
  
      @Override
      public GatewayFilter apply(Config config) {
          GatewayFilter filter = new OrderedGatewayFilter((exchange, chain) -> {
              ServerHttpRequest request = exchange.getRequest();
              ServerHttpResponse response = exchange.getResponse();
  
              log.info("Logging filter: request id -> {}", config.getBaseMessage());
  
              if (config.isPreLogger()) {
                  log.info("Logging PRE Filter: request id -> {}", request.getId());
              }
  
              return chain.filter(exchange).then(Mono.fromRunnable(() -> {
                  if (config.isPostLogger()) {
                      log.info("Logging POST Filter: response code -> {}", response.getStatusCode());
                  }
              }));
          }, Ordered.LOWEST_PRECEDENCE); // 이 부분의 값을 변경하여 해당 필터의 우선순위를 변경할 수 있음
          // Ordered.LOWEST_PRECEDENCE : 낮은 우선 순위
          // Ordered.HIGHEST_PRECEDENCE : 높은 우선 순위
  
          return filter;
      }
  
      @Data
      public static class Config {
          private String baseMessage;
          private boolean preLogger;
          private boolean postLogger;
      }
  }

• application.yml

  spring:
    application:
      name: apigateway-service
    cloud:
      gateway:
        default-filters:
          - name: GlobalFilter
            args:
              baseMessage: Spring Cloud Gateway Global Filter
              preLogger: true
              postLogger: true
  
        routes:
          - id : second-service
            uri: lb://SECOND-SERVICE
            predicates:
              - Path=/second-service/**
            filters:
              - name: LoggingFilter
                args:
                  baseMessage: Hi, there.
                  preLogger: true
                  postLogger: true