요청 및 응답 로깅 구현(issue #448) (#459)

* fix: 기본 설정을 가져와서 같은 로그가 중복으로 찍히는 오류 수정

* feat: 로그 포맷 변경

* feat: HTTP 요청 및 응답 로깅 구현

* fix: 로그 출력 작업 이후 MDC를 초기화하도록 수정

MDC는 스레드에 저장되는데, 스레드 풀링에 의해 스레드를 재사용할 때 이전 MDC가 남아있지 않도록 초기화하는 것

* feat: Trace-Id를 응답 헤더에 추가

* refactor: 필요 없는 static 키워드 삭제

* fix: 쿼리 스트링이 없을 경우 아예 출력하지 않도록 수정

* fix: Json 형태의 데이터는 이쁘게 출력하도록 변경

* fix: 오타 수정

* fix: 로그 포맷 수정

* chore: 로그가 여러 줄로 나뉘지 않도록 수정

backend/src/main/java/develup/api/logging/LoggingFilter.java

@@ -0,0 +1,154 @@
+package develup.api.logging;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+import org.springframework.web.util.ContentCachingRequestWrapper;
+import org.springframework.web.util.ContentCachingResponseWrapper;
+
+@Component
+@Order(1)
+public class LoggingFilter extends OncePerRequestFilter {
+
+    private static final Logger log = LoggerFactory.getLogger(LoggingFilter.class);
+
+    private final ObjectMapper objectMapper;
+
+    public LoggingFilter(ObjectMapper objectMapper) {
+        this.objectMapper = objectMapper;
+    }
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
+        saveTraceId(request);
+
+        ContentCachingRequestWrapper cachedRequest = new ContentCachingRequestWrapper(request);
+        ContentCachingResponseWrapper cachedResponse = new ContentCachingResponseWrapper(response);
+
+        saveRequestBody(cachedRequest);
+
+        filterChain.doFilter(cachedRequest, cachedResponse);
+
+        saveRequestMethod(cachedRequest);
+        saveRequestUri(cachedRequest);
+        saveQueryString(cachedRequest);
+        saveRequestHeader(cachedRequest);
+        printRequestLog();
+
+        addTraceIdToResponse(cachedResponse);
+        saveResponseBody(cachedResponse);
+        cachedResponse.copyBodyToResponse();
+        saveResponseHeader(cachedResponse);
+        printResponseLog();
+        MDC.clear();
+    }
+
+    private void saveTraceId(HttpServletRequest request) {
+        String header = request.getHeader("X-Request-ID");
+        if (header == null || header.isBlank()) {
+            header = UUID.randomUUID().toString();
+        }
+        MDC.put("traceId", header);
+    }
+
+    private void saveRequestBody(ContentCachingRequestWrapper cachedRequest) {
+        String content = cachedRequest.getContentAsString();
+        String prettyJsonString = toPrettyJsonString(content);
+        MDC.put("requestBody", prettyJsonString);
+    }
+
+    private String toPrettyJsonString(String jsonString) {
+        try {
+            Object json = objectMapper.readValue(jsonString, Object.class);
+            ObjectWriter writer = objectMapper.writerWithDefaultPrettyPrinter();
+            return writer.writeValueAsString(json);
+        } catch (JsonProcessingException e) {
+            return jsonString;
+        }
+    }
+
+    private void saveRequestMethod(ContentCachingRequestWrapper cachedRequest) {
+        MDC.put("method", cachedRequest.getMethod());
+    }
+
+    private void saveRequestUri(ContentCachingRequestWrapper cachedRequest) {
+        MDC.put("requestUri", cachedRequest.getRequestURI());
+    }
+
+    private void saveQueryString(ContentCachingRequestWrapper cachedRequest) {
+        String queryString = "?" + cachedRequest.getQueryString();
+        if (queryString.equals("?null")) {
+            queryString = "";
+        }
+        MDC.put("queryString", queryString);
+    }
+
+    private void saveRequestHeader(HttpServletRequest request) {
+        String headers = Collections.list(request.getHeaderNames())
+                .stream()
+                .map(headerName -> headerName + " : " + request.getHeader(headerName))
+                .collect(Collectors.joining("\n"));
+        MDC.put("requestHeaders", headers);
+    }
+
+    private void addTraceIdToResponse(HttpServletResponse response) {
+        response.addHeader("Trace-Id", MDC.get("traceId"));
+    }
+
+    private void saveResponseBody(ContentCachingResponseWrapper cachedResponse) {
+        String content = new String(cachedResponse.getContentAsByteArray());
+        MDC.put("responseBody", toPrettyJsonString(content));
+    }
+
+    private void saveResponseHeader(ContentCachingResponseWrapper cachedResponse) {
+        String responseHeader = cachedResponse.getHeaderNames()
+                .stream()
+                .map(headerName -> headerName + " : " + cachedResponse.getHeader(headerName))
+                .collect(Collectors.joining("\n"));
+        MDC.put("responseHeader", responseHeader);
+    }
+
+    private void printRequestLog() {
+        String template = """
+                Request
+                {} {}{}
+                Headers :
+                {}
+                Content :
+                {}
+                """;
+        log.info(
+                template,
+                MDC.get("method"),
+                MDC.get("requestUri"),
+                MDC.get("queryString"),
+                MDC.get("requestHeaders"),
+                MDC.get("requestBody")
+        );
+    }
+
+    private void printResponseLog() {
+        String responseLogTemplate = """
+                Response
+                Headers :
+                {}
+                Content :
+                {}
+                """;
+        log.info(responseLogTemplate, MDC.get("responseHeader"), MDC.get("responseBody"));
+    }
+}

backend/src/main/resources/logback-spring.xml

@@ -1,13 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <configuration>
-    <include resource="org/springframework/boot/logging/logback/base.xml"/>
     <springProperty scope="context" name="appName" source="spring.application.name"/>
 
     <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
             <charset>UTF-8</charset>
             <pattern>
-                %d{yyyy-MM-dd HH:mm:ss.SSS} | %t | %highlight(%-5p) | %cyan(%logger{36}) | %m%n
+                %d{yyyy-MM-dd HH:mm:ss.SSS} | %t | traceId=%X{traceId} | %highlight(%-5p) | %cyan(%logger{36}) | %m%n
             </pattern>
         </encoder>
     </appender>
@@ -18,7 +17,9 @@
         </http>
         <format>
             <label>
-                <pattern>app=${appName},host=${HOSTNAME},traceID=%X{traceId:-NONE},level=%level</pattern>
+                <pattern>
+                    %d{yyyy-MM-dd HH:mm:ss.SSS} | %t | traceId=%X{traceId} | %highlight(%-5p) | %cyan(%logger{36}) | app=${appName} | host=${HOSTNAME} | %m%n
+                </pattern>
             </label>
             <message>
                 <pattern>${FILE_LOG_PATTERN}</pattern>