feat: add logging filter

api-gateway/src/main/java/kr/mafoo/gateway/filter/APIGatewayLogger.java

@@ -0,0 +1,38 @@
+package kr.mafoo.gateway.filter;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.cloud.gateway.filter.GatewayFilterChain;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+import reactor.core.publisher.Mono;
+
+import java.net.InetSocketAddress;
+
+@Component
+public class APIGatewayLogger implements GlobalFilter {
+    private final Logger logger = LoggerFactory.getLogger(APIGatewayLogger.class);
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
+        long startTime = System.currentTimeMillis();
+        ServerHttpRequest request = exchange.getRequest();
+        ServerHttpResponse response = exchange.getResponse();
+
+        String userAgent = request.getHeaders().getFirst("User-Agent");
+        String proxyIp = request.getHeaders().getFirst("X-Forwarded-For");
+        InetSocketAddress address =  request.getRemoteAddress();
+        String originIp = proxyIp != null ? proxyIp : (address != null ? address.toString() : "UNKNOWN SOURCE");
+        String fullPath = request.getURI().getPath() + (request.getURI().getQuery() != null ? "?" + request.getURI().getQuery() : "");
+        return chain
+                .filter(exchange)
+                .doOnSuccess(resVoid -> {
+                    long executionTime = System.currentTimeMillis() - startTime;
+                    logger.info("{} {} {} {} {}ms {}", request.getMethod(), fullPath, originIp,
+                            response.getStatusCode(), executionTime, userAgent);
+                });
+    }
+}