fix: move blocking io ops to async method on dbservice init (#5291)

* move blocking io ops to async method on init

* [autofix.ci] apply automated fixes

* use correct lib

* imports

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Christophe Bornet <cbornet@hotmail.com>

src/backend/base/langflow/services/database/service.py

@@ -9,6 +9,7 @@ from datetime import datetime, timezone
 from pathlib import Path
 from typing import TYPE_CHECKING
 
+import anyio
 import sqlalchemy as sa
 from alembic import command, util
 from alembic.config import Config
@@ -43,31 +44,33 @@ class DatabaseService(Service):
             raise ValueError(msg)
         self.database_url: str = settings_service.settings.database_url
         self._sanitize_database_url()
+
         # This file is in langflow.services.database.manager.py
         # the ini is in langflow
         langflow_dir = Path(__file__).parent.parent.parent
         self.script_location = langflow_dir / "alembic"
         self.alembic_cfg_path = langflow_dir / "alembic.ini"
+
         # register the event listener for sqlite as part of this class.
         # Using decorator will make the method not able to use self
         event.listen(Engine, "connect", self.on_connection)
         self.engine = self._create_engine()
         self.async_engine = self._create_async_engine()
-        alembic_log_file = self.settings_service.settings.alembic_log_file
 
+        alembic_log_file = self.settings_service.settings.alembic_log_file
         # Check if the provided path is absolute, cross-platform.
         if Path(alembic_log_file).is_absolute():
-            # Use the absolute path directly.
             self.alembic_log_path = Path(alembic_log_file)
         else:
-            # Construct the path using the langflow directory.
             self.alembic_log_path = Path(langflow_dir) / alembic_log_file
 
-        # Ensure the directory and file for the alembic log file exists
-        self.alembic_log_path.parent.mkdir(parents=True, exist_ok=True)
-        self.alembic_log_path.touch(exist_ok=True)
         self._logged_pragma = False
 
+    async def initialize_alembic_log_file(self):
+        # Ensure the directory and file for the alembic log file exists
+        anyio.Path(self.alembic_log_path.parent).mkdir(parents=True, exist_ok=True)
+        anyio.Path(self.alembic_log_path).touch(exist_ok=True)
+
     def reload_engine(self) -> None:
         self._sanitize_database_url()
         self.engine = self._create_engine()

src/backend/base/langflow/services/utils.py

@@ -238,7 +238,9 @@ async def initialize_services(*, fix_migration: bool = False) -> None:
     get_service(ServiceType.CACHE_SERVICE, default=CacheServiceFactory())
     # Setup the superuser
     await initialize_database(fix_migration=fix_migration)
-    async with get_db_service().with_async_session() as session:
+    db_service = get_db_service()
+    await db_service.initialize_alembic_log_file()
+    async with db_service.with_async_session() as session:
         settings_service = get_service(ServiceType.SETTINGS_SERVICE)
         await setup_superuser(settings_service, session)
     try: