Closed client can create non-contextualized connections

[cepedus]

Hello,

First of all, massive thanks for this library and all the contributions of the aio-libs community 🙏

When setting up a persistent client for plugging it on an API lifespan (discussed several times before), I found out that a closed client (outside ClientCreatorContext) can still create new connections.

The issue (?) is that these connections are "loose" in the sense that the user need to explicitly await client.close() otherwise "Unclosed connector" warnings are raised, eventually leading to an runtime exception when the Python process ends.

Should the client forbid spawning new connections if outside a ClientCreatorContext?

Example code:

@asynccontextmanager
async def get_s3_client(s3_conf: S3Conf) -> AsyncGenerator[AioBaseClient]:
    session = get_session()
    session.set_credentials(
        access_key=s3_conf.access_key_id,
        secret_key=s3_conf.secret_access_key,
    )

    async with session.create_client(
        "s3",
    ) as client_ctx:
        async with client_ctx as client:
            yield client



async def test_client(s3_config: S3Conf) -> None:
    async with get_s3_client(s3_config) as client:
        _ = await client.get_object_acl(Bucket=s3_config.bucket_name, Key="demo.txt")
    # Here, `client` has no connections as expected: `client._endpoint.http_session._sessions` is empty
    _ = await client.get_object_acl(Bucket=s3_config.bucket_name, Key="demo.txt") # works
    # Here, `client._endpoint.http_session._sessions` remains non empty. During test session tear-down an exception is raised

[thehesiod]

we appreciate it, will investigate asap

[cepedus]

Hello @thehesiod, have you had the time to dig into this?

[thehesiod]

ya issue is here: async def _get_session(self, proxy_url): we are creating a new session even if the class was aexit'd. Need a flag, potentially lock, and raise exception

[thehesiod]

if you're up for a PR be happy to review, otherwise feel free to open an issue

[cepedus]

I'll open a PR in the following days 😀

[cepedus]

#1402