feat: 트래픽 중단을 위한 헬스체크 변경 API

backend/src/main/java/mouda/backend/common/HealthCheckController.java

@@ -1,14 +1,38 @@
 package mouda.backend.common;
 
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import jakarta.servlet.http.HttpServletRequest;
+
 @RestController
 public class HealthCheckController {
 
+	private static final String HOST_IP = "127.0.0.1";
+	private static final String HOST_NAME = "localhost";
+
+	private final AtomicBoolean isTerminating = new AtomicBoolean(false);
+
 	@GetMapping("/health")
 	public ResponseEntity<Void> checkHealth() {
+		if (isTerminating.get()) {
+			return ResponseEntity.status(HttpStatus.BAD_GATEWAY).build();
+		}
 		return ResponseEntity.ok().build();
 	}
+
+	@PostMapping("/termination")
+	public ResponseEntity<Void> terminate(HttpServletRequest request) {
+		String remoteAddr = request.getRemoteAddr();
+
+		if (HOST_IP.equals(remoteAddr) || HOST_NAME.equals(remoteAddr)) {
+			return ResponseEntity.ok().build();
+		}
+		return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
+	}
 }