Pipeing using exec_create, exec_start stdin, stdout

If I use the docker CL this works perfectly for me.

echo "hello" | docker exec -i $3 sh -c 'cat >/text.txt'

Now I want to use docker-py and have this so far:

ex = cli.exec_create(container='nginx-ssl', cmd='cat >/carlskii.txt')
print cli.exec_inspect(ex)
ls = cli.exec_start(exec_id=ex["Id"], tty=True)

So how do I pass the “hello” or whatever data into the exec command so that it replicates the CL command ?

Incidentally this also works perfectly locally:

p = Popen(('docker', 'exec', '-i', 'nginx-ssl', 'sh', '-c', 'cat >text.txt'), stdin=subprocess.PIPE)
p.communicate('hello\n')
p.stdin.close()

[carlskii]

@zbyte64 Could you provide a complete example here. I’m still struggling to get this to work.

Going back to my original question, I need to mimic this but using Python:

echo "hello" | docker exec -i $3 sh -c 'cat >/text.txt'

[zbyte64]

Sorry, let me clarify. To write to stdin one calls attach_socket with the appropriate flags:

socket = client.attach_socket(container_id, {
    'stdin': 1,
    'stream': 1,
})

But the socket you get back cannot be written to. Instead you must use os.write to send data to stdin:

os.write(socket.fileno(), b'echo hello world')

This usage seems awkward. But If you use TLS then you instead do:

socket.send(b'echo hello world')