Machine: Piping data from the host into docker container command not working with docker machine

[jannis-baratheon]

I've posted this on StackOverflow too: https://stackoverflow.com/questions/45811792/piping-data-from-the-host-into-docker-container-command-not-working-with-docker/45917058

The problem

I'm running Docker on Windows 10 hosted using docker-machine. I'm trying to pipe data from host into a container spawn with 'docker run' with this command:

echo test | docker run -i ubuntu:16.04 cat -

I'd expect this command to output 'test' to the stdout, but all it does is print a blank line:

jannis MINGW64 ~
$ echo test | docker run -i ubuntu:16.04 cat -

jannis MINGW64 ~
$

However when I ssh into the docker-machine the command works as expected:

jannis MINGW64 ~
$ docker-machine ssh
                        ##         .
                  ## ## ##        ==
               ## ## ## ## ##    ===
           /"""""""""""""""""\___/ ===
      ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
           \______ o           __/
             \    \         __/
              \____\_______/
 _                 _   ____     _            _
| |__   ___   ___ | |_|___ \ __| | ___   ___| | _____ _ __
| '_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ '__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__|   <  __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
Boot2Docker version 17.06.1-ce, build HEAD : 80114bc - Fri Aug 18 17:58:04 UTC 2017
Docker version 17.06.1-ce, build 874a737
docker@default:~$ echo test | docker run -i ubuntu:16.04 cat -
test

Can someone tell me:

1. Why piping into a container within docker-machine doesn't work? Is this a bug?
2. Is there a workaround for this (apart from the one provided above - ssh into the docker-machine VM)?

PS I'm using GitBash environment (based on MSYS2/MINGW) on my Windows 10 machine. Version info:

jannis MINGW64 ~
$ uname -a
MINGW64_NT-10.0 jannis 2.6.1(0.306/5/3) 2017-01-14 09:41 x86_64 Msys

jannis MINGW64 ~
$ docker version
Client:
 Version:      17.06.0-ce
 API version:  1.30
 Go version:   go1.8.3
 Git commit:   02c1d87
 Built:        Fri Jun 23 21:30:30 2017
 OS/Arch:      windows/amd64

Server:
 Version:      17.06.1-ce
 API version:  1.30 (minimum version 1.12)
 Go version:   go1.8.3
 Git commit:   874a737
 Built:        Thu Aug 17 22:54:55 2017
 OS/Arch:      linux/amd64
 Experimental: false

Current workaround

For now I'm using a workaround. I'm saving the payload I want piped to a local file, then transferring the file into the container with docker cp and next piping it locally within container.

To sum up:

What I want to do and doesn't work with docker-machine is:

echo piped content | docker run -i ubuntu:16.04 cat -

Instead I do this:

jannis MINGW64 ~
$ docker create --name test-container ubuntu:16.04 sh -c 'cat - < /tmp/emulatedpipe'
a6eaf1e5f143113bcffa9df66a47b37c124cd34447b670480b5f096d45b7b162

jannis MINGW64 ~
$ echo piped content > emulatedpipe

jannis MINGW64 ~
$ docker cp emulatedpipe test-container:/tmp

jannis MINGW64 ~
$ docker start -i test-container
piped content

[dragon788]

If you run with docker run -it to also attach a tty does it work?

I'm pretty sure SSH allocates a TTY automatically, but if you pass -t to the docker run this tells it to use a tty as well.

[jannis-baratheon]

@dragon788 Doesn't work. This is what I get:

jannis MINGW64 ~   
$ echo piped content | docker run -it ubuntu:16.04 cat -
unable to setup input stream: unable to set IO streams as raw terminal: Nieprawidłowe dojście.

PS I'm using ConEmu terminal

[jannis-baratheon]

Oh it seems to be ConEmu-specific. I tried running the command in GitBash and it works:

jannis MINGW64 ~
$ echo piped content | docker run -i ubuntu:16.04 cat -
piped content

[jannis-baratheon]

Looks like this might be related: https://github.com/moby/moby/issues/28814

With the workaround suggested in this comment I managed to make it work with ConEmu:

As a workaround, disabling ConEmu Settings -> Features -> ANSI and xterm sequences helped me.

[jannis-baratheon]

Relevant ticket in ConEmu issue tracker: https://github.com/Maximus5/ConEmu/issues/958

Seems that this is a Docker issue.

[jannis-baratheon]

Duplicate of moby/moby#28814

[alexkb]

I was having this error, and then after doing @jannis-baratheon's ANSI fix I then received a different error:

the input device is not a TTY. If you are using mintty, try prefixing the command with 'winpty'.

As the error suggests, simply prefixing the command with 'winpty' makes things work in conemu. Thanks!

[Qix-]

Bumping; -i causes blank output, -t causes @alexkb's error on Ubuntu (sans extra "mintty" message).

As of now it's not possible to both pipe data into a docker command and receive its output using just these flags. No clear indication how to do so otherwise.