Re: [Qemu-devel] [PATCH v4 1/4] tests/docker: add basic user mapping support

[Philippe Mathieu-Daudé]

Hi Alex,

I first tried "make docker-image-debian-armhf-cross NOUSER=1 V=1" which 
worked fine, then "make docker-image-debian-armhf-cross NOUSER=0" but 
got a "Image is up to date." I thought I should have to remove the image 
manually so I typed "docker rmi qemu:debian-armhf-cross" and tried again 
but still no change in my 
tests/docker/dockerfiles/debian-armhf-cross.docker adding my username, 
then I reviewed your change in the Makefile and got it, setting NOUSER 
to '0' has the same behavior, it's just set. To build the image with my 
user I had to _not_ use the flag or use it unset "NOUSER=" and it worked 
like charm.


On 02/16/2017 09:34 AM, 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"
>
> All docker containers built will add the current user unless
> explicitly disabled by specifying NOUSER when invoking the Makefile:
>
>   make docker-image-debian-armhf-cross NOUSER=1
>
> Signed-off-by: Alex Bennée <address@hidden>
> Reviewed-by: Fam Zheng <address@hidden>

Tested-by: Philippe Mathieu-Daudé <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
> v2
>   - write the useradd directly
>   - change long option to --add-current-user
> v3
>   - images -> image's
>   - add r-b
>   - add USER to Makefile
> v4
>   - s/USER/NOUSER/ and default to on
>   - fix the add-user code to skip if user already setup (for chained images)
> ---
>  tests/docker/Makefile.include |  2 ++
>  tests/docker/docker.py        | 16 ++++++++++++++--
>  2 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
> index 3f15d5aea8..4778b27ca8 100644
> --- a/tests/docker/Makefile.include
> +++ b/tests/docker/Makefile.include
> @@ -50,6 +50,7 @@ docker-image-%: $(DOCKER_FILES_DIR)/%.docker
>         $(call quiet-command,\
>                 $(SRC_PATH)/tests/docker/docker.py build qemu:$* $< \
>                 $(if $V,,--quiet) $(if $(NOCACHE),--no-cache) \
> +               $(if $(NOUSER),,--add-current-user) \
>                 $(if $(EXECUTABLE),--include-executable=$(EXECUTABLE)),\
>                 "BUILD","$*")
>
> @@ -99,6 +100,7 @@ docker:
>         @echo '                         (default is 1)'
>         @echo '    DEBUG=1              Stop and drop to shell in the created 
> container'
>         @echo '                         before running the command.'
> +       @echo '    NOUSER=1             Disable adding current user to 
> containers passwd.'
>         @echo '    NOCACHE=1            Ignore cache when build images.'
>         @echo '    EXECUTABLE=<path>    Include executable in image.'
>
> diff --git a/tests/docker/docker.py b/tests/docker/docker.py
> index 37d83199e7..d277a2268f 100755
> --- a/tests/docker/docker.py
> +++ b/tests/docker/docker.py
> @@ -25,6 +25,7 @@ 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')
> @@ -149,13 +150,21 @@ class Docker(object):
>          labels = json.loads(resp)[0]["Config"].get("Labels", {})
>          return labels.get("com.qemu.dockerfile-checksum", "")
>
> -    def build_image(self, tag, docker_dir, dockerfile, quiet=True, argv=None):
> +    def build_image(self, tag, docker_dir, dockerfile,
> +                    quiet=True, user=False, argv=None):
>          if argv == None:
>              argv = []
>
>          tmp_df = tempfile.NamedTemporaryFile(dir=docker_dir, suffix=".docker")
>          tmp_df.write(dockerfile)
>
> +        if user:
> +            uid = os.getuid()
> +            uname = getpwuid(uid).pw_name
> +            tmp_df.write("\n")
> +            tmp_df.write("RUN id %s || useradd -u %d -U %s" %
> +                         (uname, uid, uname))
> +
>          tmp_df.write("\n")
>          tmp_df.write("LABEL com.qemu.dockerfile-checksum=%s" %
>                       _text_checksum(dockerfile))
> @@ -225,6 +234,9 @@ class BuildCommand(SubCommand):
>                              help="""Specify a binary that will be copied to the
>                              container together with all its dependent
>                              libraries""")
> +        parser.add_argument("--add-current-user", "-u", dest="user",
> +                            action="store_true",
> +                            help="Add the current user to image's passwd")
>          parser.add_argument("tag",
>                              help="Image Tag")
>          parser.add_argument("dockerfile",
> @@ -261,7 +273,7 @@ class BuildCommand(SubCommand):
>                                         docker_dir)
>
>              dkr.build_image(tag, docker_dir, dockerfile,
> -                            quiet=args.quiet, argv=argv)
> +                            quiet=args.quiet, user=args.user, argv=argv)
>
>              rmtree(docker_dir)