Refactor logger setup to conditionally enable file logging.

Added error handling for file creation issues.

lightrag/utils.py

@@ -109,15 +109,17 @@ def setup_logger(
     logger_name: str,
     level: str = "INFO",
     add_filter: bool = False,
-    log_file_path: str = None,
+    log_file_path: str | None = None,
+    enable_file_logging: bool = True,
 ):
-    """Set up a logger with console and file handlers
+    """Set up a logger with console and optionally file handlers
 
     Args:
         logger_name: Name of the logger to set up
         level: Log level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
         add_filter: Whether to add LightragPathFilter to the logger
-        log_file_path: Path to the log file. If None, will use current directory/lightrag.log
+        log_file_path: Path to the log file. If None and file logging is enabled, defaults to lightrag.log in LOG_DIR or cwd
+        enable_file_logging: Whether to enable logging to a file (defaults to True)
     """
     # Configure formatters
     detailed_formatter = logging.Formatter(
@@ -125,18 +127,6 @@ def setup_logger(
     )
     simple_formatter = logging.Formatter("%(levelname)s: %(message)s")
 
-    # Get log file path
-    if log_file_path is None:
-        log_dir = os.getenv("LOG_DIR", os.getcwd())
-        log_file_path = os.path.abspath(os.path.join(log_dir, "lightrag.log"))
-
-    # Ensure log directory exists
-    os.makedirs(os.path.dirname(log_file_path), exist_ok=True)
-
-    # Get log file max size and backup count from environment variables
-    log_max_bytes = int(os.getenv("LOG_MAX_BYTES", 10485760))  # Default 10MB
-    log_backup_count = int(os.getenv("LOG_BACKUP_COUNT", 5))  # Default 5 backups
-
     logger_instance = logging.getLogger(logger_name)
     logger_instance.setLevel(level)
     logger_instance.handlers = []  # Clear existing handlers
@@ -148,6 +138,21 @@ def setup_logger(
     console_handler.setLevel(level)
     logger_instance.addHandler(console_handler)
 
+    # Add file handler by default unless explicitly disabled
+    if enable_file_logging:
+        # Get log file path
+        if log_file_path is None:
+            log_dir = os.getenv("LOG_DIR", os.getcwd())
+            log_file_path = os.path.abspath(os.path.join(log_dir, "lightrag.log"))
+
+        # Ensure log directory exists
+        os.makedirs(os.path.dirname(log_file_path), exist_ok=True)
+
+        # Get log file max size and backup count from environment variables
+        log_max_bytes = int(os.getenv("LOG_MAX_BYTES", 10485760))  # Default 10MB
+        log_backup_count = int(os.getenv("LOG_BACKUP_COUNT", 5))  # Default 5 backups
+
+        try:
             # Add file handler
             file_handler = logging.handlers.RotatingFileHandler(
                 filename=log_file_path,
@@ -158,6 +163,9 @@ def setup_logger(
             file_handler.setFormatter(detailed_formatter)
             file_handler.setLevel(level)
             logger_instance.addHandler(file_handler)
+        except PermissionError as e:
+            logger.warning(f"Could not create log file at {log_file_path}: {str(e)}")
+            logger.warning("Continuing with console logging only")
 
     # Add path filter if requested
     if add_filter: