Re: [Qemu-devel] [RFC PATCH] tests/docker: add basic user mapping support

[Fam Zheng <famz@redhat.com>]

On Tue, 12/13 13:22, Alex Bennée wrote:
> Currently all docker builds are done by exporting a tarball to the
> docker container and running the build as the containers root user.
> Other use cases are possible however and it is possible to map a part
> of users file-system to the container. This is useful for example for
> doing cross-builds of arbitrary source trees. For this to work
> smoothly the container needs to have a user created that maps cleanly
> to the host system.
> 
> This adds a -u option to the docker script so that:
> 
>   DEB_ARCH=armhf DEB_TYPE=stable ./tests/docker/docker.py build \
>     -u --include-executable=arm-linux-user/qemu-arm \
>     debian:armhf ./tests/docker/dockerfiles/debian-bootstrap.docker
> 
> Will build a container that can then be run like:
> 
>   docker run --rm -it -v /home/alex/lsrc/qemu/risu.git/:/src \
>     --user=alex:alex -w /src/ debian:armhf \
>     sh -c "make clean && ./configure -s && make"

Sorry for the late reply!

> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>  tests/docker/docker.py                           | 19 +++++++++++++++++++
>  tests/docker/dockerfiles/debian-bootstrap.docker |  3 +++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/tests/docker/docker.py b/tests/docker/docker.py
> index 37d83199e7..59baac6bae 100755
> --- a/tests/docker/docker.py
> +++ b/tests/docker/docker.py
> @@ -12,6 +12,7 @@
>  # the top-level directory.
>  
>  import os
> +import stat
>  import sys
>  import subprocess
>  import json
> @@ -25,6 +26,7 @@ import signal
>  from tarfile import TarFile, TarInfo
>  from StringIO import StringIO
>  from shutil import copy, rmtree
> +from pwd import getpwuid
>  
>  
>  DEVNULL = open(os.devnull, 'wb')
> @@ -225,6 +227,8 @@ class BuildCommand(SubCommand):
>                              help="""Specify a binary that will be copied to the
>                              container together with all its dependent
>                              libraries""")
> +        parser.add_argument("--user", "-u", action="store_true",
> +                            help="Add the current user to images passwd")

Maybe use --add-current-user for the full argument name?

>          parser.add_argument("tag",
>                              help="Image Tag")
>          parser.add_argument("dockerfile",
> @@ -260,6 +264,21 @@ class BuildCommand(SubCommand):
>                  _copy_binary_with_libs(args.include_executable,
>                                         docker_dir)
>  
> +            if args.user:
> +                uid = os.getuid()
> +                uname = getpwuid(uid).pw_name
> +                scriptlet = docker_dir+"/setup_user.sh"
> +
> +                # write scriptlet
> +                setup = open(scriptlet, "w")
> +                setup.write("#!/bin/sh\n")
> +                setup.write("useradd -u %d -U %s" % (uid, uname))
> +                setup.close()
> +
> +                st = os.stat(scriptlet)
> +                os.chmod(scriptlet,
> +                         st.st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)

Is it cleaner we inject commands into the docker file directly?

> +
>              dkr.build_image(tag, docker_dir, dockerfile,
>                              quiet=args.quiet, argv=argv)
>  
> diff --git a/tests/docker/dockerfiles/debian-bootstrap.docker b/tests/docker/dockerfiles/debian-bootstrap.docker
> index 3a9125e497..127782eedf 100644
> --- a/tests/docker/dockerfiles/debian-bootstrap.docker
> +++ b/tests/docker/dockerfiles/debian-bootstrap.docker
> @@ -14,6 +14,9 @@ RUN sed -i 's/in_target mount/echo not for docker in_target mount/g' /debootstra
>  # Run stage 2
>  RUN /debootstrap/debootstrap --second-stage
>  
> +# Do we want to tweak the user?
> +RUN if test -e /setup_user.sh; then /setup_user.sh; fi

If we do above, there is no need to manually add this in dockerfile.

> +
>  # At this point we can install additional packages if we want
>  # Duplicate deb line as deb-src
>  RUN cat /etc/apt/sources.list | sed "s/deb/deb-src/" >> /etc/apt/sources.list
> -- 
> 2.11.0
> 
> 

Fam