Re: [RFC PATCH v3 1/1] gitlab: Use plain docker in container-template.yml

[Alex Bennée]

Alex Bennée <alex.bennee@linaro.org> writes:

> Fabiano Rosas <farosas@suse.de> writes:
>
>> Our dockerfiles no longer reference layers from other qemu images so
>> we can now use 'docker build' on them.
>>
>> Also reinstate the caching that was disabled due to bad interactions
>> with certain runners. See commit 6ddc3dc7a8 ("tests/docker: don't use
>> BUILDKIT in GitLab either"). We now believe those issues to be fixed.
>>
>> The COMMON_TAG needed to be fixed for the caching to work. The
>> docker.py script was not using the variable, but constructing the
>> correct URL directly.
>>
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>> ---
>>  .gitlab-ci.d/container-template.yml | 9 ++++-----
>>  1 file changed, 4 insertions(+), 5 deletions(-)
>>
>> diff --git a/.gitlab-ci.d/container-template.yml 
>> b/.gitlab-ci.d/container-template.yml
>> index c434b9c8f3..519b8a9482 100644
>> --- a/.gitlab-ci.d/container-template.yml
>> +++ b/.gitlab-ci.d/container-template.yml
>> @@ -6,17 +6,16 @@
>>      - docker:dind
>>    before_script:
>>      - export TAG="$CI_REGISTRY_IMAGE/qemu/$NAME:latest"
>> -    - export COMMON_TAG="$CI_REGISTRY/qemu-project/qemu/$NAME:latest"
>> +    - export COMMON_TAG="$CI_REGISTRY/qemu-project/qemu/qemu/$NAME:latest"
>>      - apk add python3
>>      - docker info
>>      - docker login $CI_REGISTRY -u "$CI_REGISTRY_USER" -p 
>> "$CI_REGISTRY_PASSWORD"
>>    script:
>>      - echo "TAG:$TAG"
>>      - echo "COMMON_TAG:$COMMON_TAG"
>> -    - ./tests/docker/docker.py --engine docker build
>> -          -t "qemu/$NAME" -f "tests/docker/dockerfiles/$NAME.docker"
>> -          -r $CI_REGISTRY/qemu-project/qemu
>> -    - docker tag "qemu/$NAME" "$TAG"
>> +    - docker build --tag "$TAG" --cache-from "$TAG" --cache-from 
>> "$COMMON_TAG"
>> +      --build-arg BUILDKIT_INLINE_CACHE=1
>> +      -f "tests/docker/dockerfiles/$NAME.docker" "."
>
> I wonder why this doesn't injest a bunch of context. If I run:
>
>   docker build --cache-from
> registry.gitlab.com/stsquad/qemu/qemu/debian-alpha-cross --build-arg
> BUILDKIT_INLINE_CACHE=1 --build-arg USER=alex --build-arg UID=1000 -t
> qemu
>   /debian-alpha-cross -f 
> "/home/alex/lsrc/qemu.git/tests/docker/dockerfiles/debian-alpha-cross.docker" 
> .
>
> it attempts to bring my entire build directory in as build context. This
> is why we use the - < docker form in the Makefile.
>
>>      - docker push "$TAG"
>>    after_script:
>>      - docker logout
>
> So what I don't understand is if I do:
>
>   docker pull registry.gitlab.com/stsquad/qemu/qemu/debian-alpha-cross
>   docker build --cache-from 
> registry.gitlab.com/stsquad/qemu/qemu/debian-alpha-cross --build-arg
>     BUILDKIT_INLINE_CACHE=1 -t qemu/debian-alpha-cross - <
>     
> /home/alex/lsrc/qemu.git/tests/docker/dockerfiles/debian-alpha-cross.docker
>
> I still see pretty much a full rebuild of the image.

For reference at the end:

  🕙19:37:36 alex@zen:container-diff.git  on  master took 19s 
  ➜  ./out/container-diff diff 
daemon://registry.gitlab.com/stsquad/qemu/qemu/debian-alpha-cross 
daemon://qemu/debian-alpha-cross --type=file

  -----File-----

  These entries have been added to qemu/debian-alpha-cross:
  FILE                                 SIZE
  /usr/share/doc/base-files/FAQ        6B
  /usr/share/info/dir                  781B

  These entries have been deleted from qemu/debian-alpha-cross: None

  These entries have been changed between 
registry.gitlab.com/stsquad/qemu/qemu/debian-alpha-cross and 
qemu/debian-alpha-cross:
  FILE                                        SIZE1         SIZE2
  /var/cache/debconf/templates.dat            762.2K        764.1K
  /var/cache/debconf/templates.dat-old        762.2K        764.1K
  /var/lib/dpkg/available                     70.7K         70.7K
  /var/log/dpkg.log                           12.9K         20.2K
  /var/log/apt/term.log                       7.4K          15.5K
  /var/cache/ldconfig/aux-cache               5.5K          5.5K
  /var/cache/debconf/config.dat-old           4.5K          4.7K
  /var/log/apt/history.log                    1.5K          2K
  /etc/shadow                                 501B          501B
  /etc/shadow-                                501B          501B
  /etc/apt/sources.list                       430B          430B

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro