Leaking file descriptors

[srdjan-catalyst]

There are two places where file descriptors are being leaked , at least with python 3.8:

1. _get_raw_response_socket(): in case of Unix sockets, additional referencing seems to stop them from being closed
2. When DockerClient is not used as a context manager it does not call close() on the api session object.

I have managed to work around with:

class FixedAPIClient(docker.APIClient):
    def _get_raw_response_socket(self, response):
        sock = super()._get_raw_response_socket(response)
        if self.base_url.startswith('http+docker://'):
            sock._response = None
        return sock


class FixedDockerClient(docker.DockerClient):
    def __init__(self, *args, **kwargs):
        self.api = FixedAPIClient(*args, **kwargs)

    def __del__(self):
        try:
            if self.api:
                self.api.close()
        except AttributeError:
            pass

Our setup is quite complex. If you believe this should not happen and it is a corner case I will try to come up with a minimal example.

[feliperuhland]

Hi @srdjan-catalyst

I´m working on #2808, and your request is essential to be delivered together.

I will mention this issue in the commit message.

Thanks and have a nice day :)

[Hoohaha]

I have same problem in my local. As a workaround you can close client to force release the sockets.