Closing stdin on a Running Container

I am using docker version 2.1.0.

When starting a container the parameter stdin_open can be used to prepare the stdin socket for writing. I have had success doing this with code along these lines,

stdin_data = 'some data to send to stdin'

container = client.containers.run(image, detach=True, stdin_open=True)

socket = container.attach_socket(params={'stdin': 1, 'stream': 1})
os.write(socket.fileno(), stdin_data.encode())
socket.close()

exit_code = container.wait()

I have also found that this approach can easily hang indefinitely, if the underlying container is waiting for input. The reason seems to be be that the socket status is independent of the stdin_open parameter, so the code running in the container never receives an EOF-like sentinel on stdin.

Any suggestions on how to address this?

Start with the client.containers.run, container.attach_socket, and container.wait calls shown in the report, then reproduce the hang with a container waiting for input. Determine how the Docker Engine API and this library represent closing stdin; done means a documented, tested way to signal EOF and allow wait() to return.