Docker-py: Copy to container

[egelmex]

The docker API shows that the docker cli can be used to copy files to and from containers, but the only command I can find in the API is for copying an archive off the container.

https://docs.docker.com/engine/reference/commandline/cp/

docker==2.5.1
docker-pycreds==0.2.1
Python 3.5.3
Client:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.7.4
 Git commit:   78d1802
 Built:        Tue Mar 14 09:47:15 2017
 OS/Arch:      linux/amd64

Server:
 Version:      1.12.6
 API version:  1.24
 Go version:   go1.7.4
 Git commit:   78d1802
 Built:        Tue Mar 14 09:47:15 2017
 OS/Arch:      linux/amd64

[shin-]

Yes, put_archive and get_archive are the methods to use to copy to and from containers.

[egelmex]

Are there any plans to match feature parity of docker cp? In my use case I am generating a single files that I wish to copy onto containers.

[artgoldberg]

One problem with tar archives is that the historical tar formats do not support encodings, so they're not compatible with unicode filenames. Do you support the POSIX.1-2001 pax format which resolves this issue?

[artgoldberg]

@egelmex:
There are a couple of ways to work around the absence of cp in the docker API.

1. Simply issue a 'docker cp ...' shell command.
2. Reuse some of the Docker API code in docker-py/docker/utils/build.py and docker-py/tests/integration/api_container_test.py to build a utility that takes a path and builds a temporary tar archive and then puts it in your container.
   Arthur

[smheidrich]

Related: #1027 (if one of them should be closed due to being a duplicate, I would close #1027 because #1771 here is more general).

Also, is there a PR implementing a convenience method for this by now?

[shin-]

You can take a look at what we do in our integration tests: https://github.com/docker/docker-py/blob/master/tests/helpers.py#L29-L38

I don't think it's particularly necessary to add that kind of helper to the library. The current implementation matches what the API provides, has a clear interface and advertises clearly what the expected input/output is - that's not something I want to blur with additional convenience methods.

[smheidrich]

@shin-, fair enough, thanks for the example code from the integration tests! :+1: