Confusing AsyncResource closing Mechanism with FastAPI #719
Description
Hello ets-labs, I felt really great on this morning for applying this awesome tool!
I almost had been finishing organizing dependency injection with fastapi during today, but there was a issue when closing AsyncResouces with on_shutdown of FastAPI.
I am on Mac with python 3.11.4, current version of installed D.I. is 4.41.0.
This works unexpectedly, remaining unclosed session.
from dependency_injector import providers, containers, resources, wiring from aiohttp import ClientSession import asyncio from fastapi import FastAPI class AsyncHttpClient(resources.AsyncResource): async def init(self) -> ClientSession: return ClientSession() async def shutdown(self, client_session: ClientSession | None): if client_session is not None: await client_session.close() class Container(containers.DeclarativeContainer): wiring_config = containers.WiringConfiguration( modules=[__name__] ) async_resource = providers.Resource(AsyncHttpClient) async def main(): container = Container() await container.init_resources() app = FastAPI( on_shutdown=[container.shutdown_resources], ) if __name__ == "__main__": asyncio.run(main()) >>> Unclosed client session client_session: <aiohttp.client.ClientSession object at xxxxxxx>Below is working clean, remaining no unclosed session.
from dependency_injector import providers, containers, resources, wiring from aiohttp import ClientSession import asyncio from fastapi import FastAPI class AsyncHttpClient(resources.AsyncResource): async def init(self) -> ClientSession: return ClientSession() async def shutdown(self, client_session: ClientSession | None): if client_session is not None: await client_session.close() class Container(containers.DeclarativeContainer): wiring_config = containers.WiringConfiguration( modules=[__name__] ) async_resource = providers.Resource(AsyncHttpClient) @wiring.inject async def inner(client=wiring.Provide[Container.async_resource]): resp = await client.get("https://ipconfig.io/json") print(await resp.json()) async def main(): container = Container() await container.init_resources() app = FastAPI( on_shutdown=[container.shutdown_resources], ) if __name__ == "__main__": asyncio.run(main())The only difference is existence of injected function. If injected function is, it succeed to closing and vice versa.(Even, I am not using it)
I had tried making closing first for hours, so I could not find solution. Luckily, I tested another way and found the way.
Would you tell me any mechanism about this ?