fix: logger config and env file loading (#4174)

* fix: logger config and env file loading

* fix: mypy error assignment and arg-type

src/backend/base/langflow/__main__.py

@@ -149,13 +149,12 @@ def run(
     ),
 ) -> None:
     """Run Langflow."""
-    configure(log_level=log_level, log_file=log_file)
-    set_var_for_macos_issue()
-
     if env_file:
         load_dotenv(env_file, override=True)
-        logger.debug(f"Loading config from file: '{env_file}'")
 
+    configure(log_level=log_level, log_file=log_file)
+    logger.debug(f"Loading config from file: '{env_file}'" if env_file else "No env_file provided.")
+    set_var_for_macos_issue()
     settings_service = get_settings_service()
 
     frame = inspect.currentframe()

src/backend/base/langflow/logging/logger.py

@@ -150,6 +150,10 @@ def configure(
     if log_level is None:
         log_level = "ERROR"
 
+    if log_file is None:
+        env_log_file = os.getenv("LANGFLOW_LOG_FILE", "")
+        log_file = Path(env_log_file) if env_log_file else None
+
     if log_env is None:
         log_env = os.getenv("LANGFLOW_LOG_ENV", "")