GitLab CI DIND: timeout error

Expected Behavior

docker-slim should run without error when run in a GitLab CI environment

Actual Behavior

docker-slim fails with timeout error.

Steps to Reproduce the Problem

1. Create a GitLab CI project with a Dockerfile in it and the following .gitlab-ci.yml file:

---
gitlab_registry:
  stage: test
  image: megabytelabs/dockerslim:latest
  needs: []
  services:
    - docker:dind
  tags:
    - docker
  variables:
    DOCKER_HOST: tcp://docker:2376
    DOCKER_TLS_CERTDIR: /certs
    DOCKER_CERT_PATH: "$DOCKER_TLS_CERTDIR/client"
    DOCKER_TLS_VERIFY: 1
    GIT_DEPTH: 1
  script:
    - docker login -u "${CI_REGISTRY_USER}" -p "${CI_REGISTRY_PASSWORD}" "${CI_REGISTRY}"
    - docker build -t "${CI_COMMIT_REF_SLUG}:latest" .
    - docker-slim --debug --tls-verify=false build --http-probe=false --exec 'echo hey' "${CI_COMMIT_REF_SLUG}:latest"

2. Trigger the CI build. Docker commands are working as expected but the docker-slim build fails with the following output:

Running with gitlab-runner 13.12.0-rc1 (b21d5c5b)
  on docker-auto-scale 0277ea0f
  feature flags: FF_GITLAB_REGISTRY_HELPER_IMAGE:true, FF_SKIP_DOCKER_MACHINE_PROVISION_ON_CREATION_FAILURE:true
Resolving secrets
00:00
Preparing the "docker+machine" executor
Using Docker executor with image megabytelabs/dockerslim:latest ...
Starting service docker:dind ...
Pulling docker image docker:dind ...
Using docker image sha256:dc8c389414c80f3c6510d3690cd03c29fc99d66f58955f138248499a34186bfa for docker:dind with digest docker@sha256:87ed8e3a7b251eef42c2e4251f95ae3c5f8c4c0a64900f19cc532d0a42aa7107 ...
Waiting for services to be up and running...
Pulling docker image megabytelabs/dockerslim:latest ...
Using docker image sha256:383b8ff911c08e8a29b6cc8a75d8069fec480f71d9c773ed3f96a4a8486b46ec for megabytelabs/dockerslim:latest with digest megabytelabs/dockerslim@sha256:c21249ab64d840452d81e796952341649ed8774665b1285ae92a4f47998c0022 ...
Preparing environment
00:00
Running on runner-0277ea0f-project-25813727-concurrent-0 via runner-0277ea0f-srm-1621013830-ed04e4e1...
Getting source from Git repository
00:02
$ eval "$CI_PRE_CLONE_SCRIPT"
Fetching changes with git depth set to 1...
Initialized empty Git repository in /builds/megabyte-labs/dockerfile/ci-pipeline/yamllint/.git/
Created fresh repository.
Checking out 417f788b as master...
Skipping Git submodules setup
Executing "step_script" stage of the job script
Using docker image sha256:383b8ff911c08e8a29b6cc8a75d8069fec480f71d9c773ed3f96a4a8486b46ec for megabytelabs/dockerslim:latest with digest megabytelabs/dockerslim@sha256:c21249ab64d840452d81e796952341649ed8774665b1285ae92a4f47998c0022 ...
$ docker login -u "${CI_REGISTRY_USER}" -p "${CI_REGISTRY_PASSWORD}" "${CI_REGISTRY}"
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store
Login Succeeded
$ docker build -t "${CI_COMMIT_REF_SLUG}:latest" .
Step 1/20 : FROM alpine:3
3: Pulling from library/alpine
540db60ca938: Pulling fs layer
540db60ca938: Verifying Checksum
540db60ca938: Download complete
540db60ca938: Pull complete
Digest: sha256:69e70a79f2d41ab5d637de98c1e0b055206ba40a8145e7bddb55ccc04e13cf8f
Status: Downloaded newer image for alpine:3
 ---> 6dbb9cc54074
Step 2/20 : ENV container docker
 ---> Running in 5633d9ac9aab
Removing intermediate container 5633d9ac9aab
 ---> b177e9721c4f
Step 3/20 : RUN apk --no-cache add --virtual build-dependencies       py3-pip=20.3.4-r0   && apk --no-cache add       python3=3.8.10-r0   && pip3 install --no-cache-dir       yamllint==1.26.1   && apk del build-dependencies   && rm -Rf /var/cache/apk/*
 ---> Running in 35b9887db817
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
(1/36) Installing libbz2 (1.0.8-r1)
(2/36) Installing expat (2.2.10-r1)
(3/36) Installing libffi (3.3-r2)
(4/36) Installing gdbm (1.19-r0)
(5/36) Installing xz-libs (5.2.5-r0)
(6/36) Installing ncurses-terminfo-base (6.2_p20210109-r0)
(7/36) Installing ncurses-libs (6.2_p20210109-r0)
(8/36) Installing readline (8.1.0-r0)
(9/36) Installing sqlite-libs (3.34.1-r0)
(10/36) Installing python3 (3.8.10-r0)
(11/36) Installing py3-appdirs (1.4.4-r1)
(12/36) Installing py3-ordered-set (4.0.2-r0)
(13/36) Installing py3-parsing (2.4.7-r1)
(14/36) Installing py3-six (1.15.0-r0)
(15/36) Installing py3-packaging (20.9-r0)
(16/36) Installing py3-setuptools (51.3.3-r0)
(17/36) Installing py3-chardet (4.0.0-r0)
(18/36) Installing py3-idna (3.1-r0)
(19/36) Installing py3-urllib3 (1.26.2-r1)
(20/36) Installing py3-requests (2.25.1-r1)
(21/36) Installing py3-msgpack (1.0.2-r0)
(22/36) Installing py3-lockfile (0.12.2-r3)
(23/36) Installing py3-cachecontrol (0.12.6-r0)
(24/36) Installing py3-colorama (0.4.4-r0)
(25/36) Installing py3-contextlib2 (0.6.0-r0)
(26/36) Installing py3-distlib (0.3.1-r1)
(27/36) Installing py3-distro (1.5.0-r1)
(28/36) Installing py3-webencodings (0.5.1-r3)
(29/36) Installing py3-html5lib (1.1-r0)
(30/36) Installing py3-pytoml (0.1.21-r0)
(31/36) Installing py3-pep517 (0.9.1-r0)
(32/36) Installing py3-progress (1.5-r0)
(33/36) Installing py3-retrying (1.3.3-r0)
(34/36) Installing py3-toml (0.10.2-r0)
(35/36) Installing py3-pip (20.3.4-r0)
(36/36) Installing build-dependencies (20210514.173827)
Executing busybox-1.32.1-r6.trigger
OK: 75 MiB in 50 packages
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
OK: 75 MiB in 50 packages
Collecting yamllint==1.26.1
  Downloading yamllint-1.26.1.tar.gz (126 kB)
Collecting pathspec>=0.5.3
  Downloading pathspec-0.8.1-py2.py3-none-any.whl (28 kB)
Collecting pyyaml
  Downloading PyYAML-5.4.1.tar.gz (175 kB)
  Installing build dependencies: started
  Installing build dependencies: finished with status 'done'
  Getting requirements to build wheel: started
  Getting requirements to build wheel: finished with status 'done'
    Preparing wheel metadata: started
    Preparing wheel metadata: finished with status 'done'
Using legacy 'setup.py install' for yamllint, since package 'wheel' is not installed.
Building wheels for collected packages: pyyaml
  Building wheel for pyyaml (PEP 517): started
  Building wheel for pyyaml (PEP 517): finished with status 'done'
  Created wheel for pyyaml: filename=PyYAML-5.4.1-cp38-cp38-linux_x86_64.whl size=45641 sha256=877f5c66f7f4841b24843d0d0f0fb94e7de2f892a282030f82208f393289c172
  Stored in directory: /tmp/pip-ephem-wheel-cache-63w9bcle/wheels/dd/c5/1d/5d7436173d3efd4a14dcb510eb0b29525ecb6b0e41489e716e
Successfully built pyyaml
Installing collected packages: pyyaml, pathspec, yamllint
    Running setup.py install for yamllint: started
    Running setup.py install for yamllint: finished with status 'done'
Successfully installed pathspec-0.8.1 pyyaml-5.4.1 yamllint-1.26.1
WARNING: Ignoring https://dl-cdn.alpinelinux.org/alpine/v3.13/main: No such file or directory
WARNING: Ignoring https://dl-cdn.alpinelinux.org/alpine/v3.13/community: No such file or directory
(1/26) Purging build-dependencies (20210514.173827)
(2/26) Purging py3-pip (20.3.4-r0)
(3/26) Purging py3-cachecontrol (0.12.6-r0)
(4/26) Purging py3-lockfile (0.12.2-r3)
(5/26) Purging py3-colorama (0.4.4-r0)
(6/26) Purging py3-contextlib2 (0.6.0-r0)
(7/26) Purging py3-distlib (0.3.1-r1)
(8/26) Purging py3-distro (1.5.0-r1)
(9/26) Purging py3-html5lib (1.1-r0)
(10/26) Purging py3-msgpack (1.0.2-r0)
(11/26) Purging py3-pep517 (0.9.1-r0)
(12/26) Purging py3-pytoml (0.1.21-r0)
(13/26) Purging py3-progress (1.5-r0)
(14/26) Purging py3-requests (2.25.1-r1)
(15/26) Purging py3-chardet (4.0.0-r0)
(16/26) Purging py3-idna (3.1-r0)
(17/26) Purging py3-urllib3 (1.26.2-r1)
(18/26) Purging py3-retrying (1.3.3-r0)
(19/26) Purging py3-setuptools (51.3.3-r0)
(20/26) Purging py3-ordered-set (4.0.2-r0)
(21/26) Purging py3-appdirs (1.4.4-r1)
(22/26) Purging py3-packaging (20.9-r0)
(23/26) Purging py3-parsing (2.4.7-r1)
(24/26) Purging py3-six (1.15.0-r0)
(25/26) Purging py3-toml (0.10.2-r0)
(26/26) Purging py3-webencodings (0.5.1-r3)
Executing busybox-1.32.1-r6.trigger
OK: 53 MiB in 24 packages
Removing intermediate container 35b9887db817
 ---> 42fbfd532903
Step 4/20 : WORKDIR /work
 ---> Running in 6021fb838d36
Removing intermediate container 6021fb838d36
 ---> e577bd51ef96
Step 5/20 : CMD ["yamllint", "--version"]
 ---> Running in 5fd4acde5fcb
Removing intermediate container 5fd4acde5fcb
 ---> 707a4e31146c
Step 6/20 : ARG BUILD_DATE
 ---> Running in 2d05149992d0
Removing intermediate container 2d05149992d0
 ---> 3dc1350b9cc6
Step 7/20 : ARG REVISION
 ---> Running in a1378959cdc8
Removing intermediate container a1378959cdc8
 ---> 157cff7ac860
Step 8/20 : ARG VERSION
 ---> Running in 91cfaa6c36f0
Removing intermediate container 91cfaa6c36f0
 ---> c82f2a79a67f
Step 9/20 : LABEL maintainer="Megabyte Labs <help@megabyte.space"
 ---> Running in 6b299b749337
Removing intermediate container 6b299b749337
 ---> a23b0e61c651
Step 10/20 : LABEL org.opencontainers.image.authors="Brian Zalewski <brian@megabyte.space>"
 ---> Running in aaa702f8739b
Removing intermediate container aaa702f8739b
 ---> 179294040d60
Step 11/20 : LABEL org.opencontainers.image.created=$BUILD_DATE
 ---> Running in 28cf86ff3b43
Removing intermediate container 28cf86ff3b43
 ---> d57eb219f866
Step 12/20 : LABEL org.opencontainers.image.description="An incredibly compact YAML Lint container that you can use in CI environments as well as from the command-line as a one-liner (only 3.21997 MB compressed!)"
 ---> Running in dd58c6e68c5b
Removing intermediate container dd58c6e68c5b
 ---> 70241d26333c
Step 13/20 : LABEL org.opencontainers.image.documentation="https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint/-/blob/master/README.md"
 ---> Running in 942a0b796677
Removing intermediate container 942a0b796677
 ---> 8b58f5ca076e
Step 14/20 : LABEL org.opencontainers.image.licenses="MIT"
 ---> Running in f4720da47785
Removing intermediate container f4720da47785
 ---> 8badffc09f5e
Step 15/20 : LABEL org.opencontainers.image.revision=$REVISION
 ---> Running in 21e020722a88
Removing intermediate container 21e020722a88
 ---> 6ee378250f76
Step 16/20 : LABEL org.opencontainers.image.source="https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint.git"
 ---> Running in 3a86e3acfb62
Removing intermediate container 3a86e3acfb62
 ---> 36ee118325a8
Step 17/20 : LABEL org.opencontainers.image.url="https://megabyte.space"
 ---> Running in 6902612d6ea8
Removing intermediate container 6902612d6ea8
 ---> 7856ce7d7760
Step 18/20 : LABEL org.opencontainers.image.vendor="Megabyte Labs"
 ---> Running in 4692e2e96213
Removing intermediate container 4692e2e96213
 ---> 65c98cefaf27
Step 19/20 : LABEL org.opencontainers.image.version=$VERSION
 ---> Running in 6395eaaa7b24
Removing intermediate container 6395eaaa7b24
 ---> 009f738fe80e
Step 20/20 : LABEL space.megabyte.type="ci-pipeline"
 ---> Running in 557e14a54a04
Removing intermediate container 557e14a54a04
 ---> 6db846ce739a
Successfully built 6db846ce739a
Successfully tagged master:latest
$ docker-slim --debug --tls-verify=false build --http-probe=false --exec 'yamllint .' "${CI_COMMIT_REF_SLUG}:latest"
time="2021-05-14T17:38:44Z" level=debug msg="sysinfo => system.SystemInfo{Sysname:\"Linux\", Nodename:\"runner-0277ea0f-project-25813727-concurrent-0\", Release:\"4.19.78-coreos\", Version:\"#1 SMP Mon Oct 14 22:56:39 -00 2019\", Machine:\"x86_64\", Domainname:\"(none)\", OsBuild:\"\", Distro:system.DistroInfo{Name:\"Alpine Linux\", Version:\"3.13.5\", DisplayName:\"Alpine Linux v3.13\"}}"
docker-slim: message='join the Gitter channel to ask questions or to share your feedback' info='https://gitter.im/docker-slim/community'
docker-slim: message='join the Discord server to ask questions or to share your feedback' info='https://discord.gg/9tDyxYS'
docker-slim: message='Github discussions' info='https://github.com/docker-slim/docker-slim/discussions'
cmd=build info=exec message='changing continue-after mode to exec' 
time="2021-05-14T17:38:44Z" level=debug msg="docker-slim: new Docker client (TLS,no verify) [4]"
cmd=build state=started
cmd=build info=params target='master:latest' continue.mode='exec' rt.as.user='true' keep.perms='true' 
time="2021-05-14T17:38:44Z" level=info msg="image=master:latest http-probe=false remove-file-artifacts=false image-overrides=map[] entrypoint=[] (false) cmd=[] (false) workdir='' env=[] expose=map[]" app=docker-slim command=build
cmd=build info=app version='linux|Transformer|1.35.1|89ddd87f009dd1e7cbd66a5494e5956c3c093edc|2021-04-27_07:10:07PM' container=true dsimage=false
cmd=build info=app location='/usr/local/bin'
cmd=build info=host osname='Alpine Linux v3.13'
cmd=build info=host osbuild=
cmd=build info=host version='#1 SMP Mon Oct 14 22:56:39 -00 2019'
cmd=build info=host release=4.19.78-coreos
cmd=build info=host sysname=Linux
cmd=build info=docker name=32fd90fcb8bb
cmd=build info=docker kernel_version=4.19.78-coreos
cmd=build info=docker operating_system=Alpine Linux v3.13 (containerized)
cmd=build info=docker ostype=linux
cmd=build info=docker server_version=20.10.6
cmd=build info=docker architecture=x86_64
cmd=build info=dclient api_version=1.41
cmd=build info=dclient min_api_version=1.12
cmd=build info=dclient build_time=2021-04-09T22:46:14.000000000+00:00
cmd=build info=dclient git_commit=8728dd2
cmd=build state=image.inspection.start
time="2021-05-14T17:38:44Z" level=info msg="inspecting 'fat' image metadata..." app=docker-slim command=build
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs(,sha256:6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530)"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - statePrefix=/usr/local/bin appDir=/usr/local/bin badPath=/usr/local/bin"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - overriding state path to /tmp/docker-slim-state"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - statePrefix=/tmp/docker-slim-state appDir=/usr/local/bin badPath=/usr/local/bin"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - copying sensor to state path (to /tmp/docker-slim-state)"
time="2021-05-14T17:38:44Z" level=debug msg="CopyRegularFile(false,/usr/local/bin/docker-slim-sensor,/tmp/docker-slim-state/docker-slim-sensor,true)"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - will create new state location: /tmp/docker-slim-state/.docker-slim-state/images/6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530/artifacts"
time="2021-05-14T17:38:44Z" level=debug msg="PrepareImageStateDirs - created new image state location: /tmp/docker-slim-state/.docker-slim-state/images/6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530/artifacts"
time="2021-05-14T17:38:44Z" level=debug msg="localVolumePath=/tmp/docker-slim-state/.docker-slim-state/images/6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530, artifactLocation=/tmp/docker-slim-state/.docker-slim-state/images/6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530/artifacts, statePath=/tmp/docker-slim-state, stateKey=6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530" app=docker-slim command=build
cmd=build info=image size.human='52 MB' id='sha256:6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530' size.bytes='52089452' 
time="2021-05-14T17:38:44Z" level=info msg="processing 'fat' image info..." app=docker-slim command=build
time="2021-05-14T17:38:44Z" level=debug msg="\n\nIMAGE HISTORY =>\n[]docker.ImageHistory{docker.ImageHistory{ID:\"sha256:6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530\", Tags:[]string{\"master:latest\"}, Created:1621013924, CreatedBy:\"/bin/sh -c #(nop)  LABEL space.megabyte.type=ci-pipeline\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:009f738fe80edb4066f1d400b215b89a31049e747bfb9991d63cacd268e750b6\", Tags:[]string(nil), Created:1621013924, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.version=\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:65c98cefaf2782b17c566b065db0b7f105443bda51c466a3b00489c195207745\", Tags:[]string(nil), Created:1621013924, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.vendor=Megabyte Labs\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:7856ce7d776034950aa6a000faf9a820e52688c48c48ea23fc11aa9da3cc0624\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.url=https://megabyte.space\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:36ee118325a8d7b8ab8c95df5f44fb043b2eae1673521c799dfd89cf1b9db392\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.source=https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint.git\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:6ee378250f76a3595fb2fae2d9ddbc9386a1fad4708c8204dbe96058c6cd9c5e\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.revision=\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:8badffc09f5ec3edf83665febef736697b7b19984500a637623bcb2f2d7075f5\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.licenses=MIT\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:8b58f5ca076ee77f0b27208126abbb5bb12d81b43f2eec96dc5f6e32e638d5f7\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.documentation=https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint/-/blob/master/README.md\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:70241d26333cc48ef20772aefc7394a458c22d94b6f3e75b25230f4ce2c01d79\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.description=An incredibly compact YAML Lint container that you can use in CI environments as well as from the command-line as a one-liner (only 3.21997 MB compressed!)\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:d57eb219f866f188bb5724396bf25f1f921706cb342dfe0bcb14f199924f5c67\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.created=\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:179294040d6010d4a7c09b2169d985a9427407959de4a981a36d6aacd4e248b3\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL org.opencontainers.image.authors=Brian Zalewski <brian@megabyte.space>\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:a23b0e61c6513695b06cfcd06cf8e7cb8c0810612b701f871bff8adbb75c4c19\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  LABEL maintainer=Megabyte Labs <help@megabyte.space\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:c82f2a79a67fca3e57ef5283255ac45cd0769479d2c901e459602048082b26d1\", Tags:[]string(nil), Created:1621013923, CreatedBy:\"/bin/sh -c #(nop)  ARG VERSION\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:157cff7ac8604e75bf2ba52ba3e1e60ded5dd127701a3ada6f5f26b69cf9c5ae\", Tags:[]string(nil), Created:1621013922, CreatedBy:\"/bin/sh -c #(nop)  ARG REVISION\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:3dc1350b9cc6a7621e35229e6773af3868e56f607ae04156d20c33694bbf03a4\", Tags:[]string(nil), Created:1621013922, CreatedBy:\"/bin/sh -c #(nop)  ARG BUILD_DATE\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:707a4e31146cc4f53204c658e7392b97944ff0b9630eaa350f8e3a8eee948b3f\", Tags:[]string(nil), Created:1621013922, CreatedBy:\"/bin/sh -c #(nop)  CMD [\\\"yamllint\\\" \\\"--version\\\"]\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:e577bd51ef96d43ebe3f3e64ce80783810c9c87bc9e3691a418f66d7b6e36982\", Tags:[]string(nil), Created:1621013922, CreatedBy:\"/bin/sh -c #(nop) WORKDIR /work\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:42fbfd532903bf42c288e015eab2d6c505f5b097dc756ffd39994d6f105e35f5\", Tags:[]string(nil), Created:1621013922, CreatedBy:\"/bin/sh -c apk --no-cache add --virtual build-dependencies       py3-pip=20.3.4-r0   && apk --no-cache add       python3=3.8.10-r0   && pip3 install --no-cache-dir       yamllint==1.26.1   && apk del build-dependencies   && rm -Rf /var/cache/apk/*\", Size:46476294, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:b177e9721c4fbe30d8b5b5be2ea7784f47b70a7a82f43ef3b5914804324e311b\", Tags:[]string(nil), Created:1621013906, CreatedBy:\"/bin/sh -c #(nop)  ENV container=docker\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"sha256:6dbb9cc54074106d46d4ccb330f2a40a682d49dda5f4844962b7dce9fe44aaec\", Tags:[]string{\"alpine:3\"}, Created:1618427979, CreatedBy:\"/bin/sh -c #(nop)  CMD [\\\"/bin/sh\\\"]\", Size:0, Comment:\"\"}, docker.ImageHistory{ID:\"<missing>\", Tags:[]string(nil), Created:1618427979, CreatedBy:\"/bin/sh -c #(nop) ADD file:8ec69d882e7f29f0652d537557160e638168550f738d0d49f90a7ef96bf31787 in / \", Size:5613158, Comment:\"\"}}\n\n"
time="2021-05-14T17:38:44Z" level=debug msg="IMAGE INSTRUCTIONS:"
time="2021-05-14T17:38:44Z" level=debug msg="FROM scratch"
time="2021-05-14T17:38:44Z" level=debug msg="# new image"
time="2021-05-14T17:38:44Z" level=debug msg="ADD file:8ec69d882e7f29f0652d537557160e638168550f738d0d49f90a7ef96bf31787 /"
time="2021-05-14T17:38:44Z" level=debug msg="CMD [\"/bin/sh\"]"
time="2021-05-14T17:38:44Z" level=debug msg="# end of image: alpine:3 (id:  tags: alpine:3)"
time="2021-05-14T17:38:44Z" level=debug
time="2021-05-14T17:38:44Z" level=debug msg="# new image"
time="2021-05-14T17:38:44Z" level=debug msg="ENV container=docker"
time="2021-05-14T17:38:44Z" level=debug msg="RUN apk --no-cache add --virtual build-dependencies       py3-pip=20.3.4-r0 && \\\n\tapk --no-cache add       python3=3.8.10-r0 && \\\n\tpip3 install --no-cache-dir       yamllint==1.26.1 && \\\n\tapk del build-dependencies && \\\n\trm -Rf /var/cache/apk/*"
time="2021-05-14T17:38:44Z" level=debug msg="WORKDIR /work"
time="2021-05-14T17:38:44Z" level=debug msg="CMD [\"yamllint\",\"--version\"]"
time="2021-05-14T17:38:44Z" level=debug msg="ARG BUILD_DATE"
time="2021-05-14T17:38:44Z" level=debug msg="ARG REVISION"
time="2021-05-14T17:38:44Z" level=debug msg="ARG VERSION"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL maintainer=Megabyte Labs <help@megabyte.space"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.authors=Brian Zalewski <brian@megabyte.space>"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.created="
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.description=An incredibly compact YAML Lint container that you can use in CI environments as well as from the command-line as a one-liner (only 3.21997 MB compressed!)"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.documentation=https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint/-/blob/master/README.md"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.licenses=MIT"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.revision="
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.source=https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/yamllint.git"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.url=https://megabyte.space"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.vendor=Megabyte Labs"
time="2021-05-14T17:38:44Z" level=debug msg="LABEL org.opencontainers.image.version="
time="2021-05-14T17:38:44Z" level=debug msg="LABEL space.megabyte.type=ci-pipeline"
time="2021-05-14T17:38:44Z" level=debug msg="# end of image: master:latest (id:  tags: master:latest)"
time="2021-05-14T17:38:44Z" level=debug
cmd=build info=image.stack index='0' name='alpine:3' id='sha256:6dbb9cc54074106d46d4ccb330f2a40a682d49dda5f4844962b7dce9fe44aaec' 
cmd=build info=image.stack name='master:latest' id='sha256:6db846ce739a8656ce1ae8a922d7de63663fd01740cdf5864b78b08a32257530' index='1' 
cmd=build state=image.inspection.done
cmd=build state=container.inspection.start
time="2021-05-14T17:38:44Z" level=debug msg="FatContainerCmd - [yamllint --version]" app=docker-slim command=build component=container.inspector
time="2021-05-14T17:38:44Z" level=info msg="starting instrumented 'fat' container..." app=docker-slim command=build
time="2021-05-14T17:38:44Z" level=debug msg="RunContainer: sensor (/usr/local/bin/docker-slim-sensor) perms => 0755" app=docker-slim command=build component=container.inspector
time="2021-05-14T17:38:44Z" level=debug msg="dockerutil.HasVolume: volume not found - docker-slim-sensor.1.35.1"
time="2021-05-14T17:38:44Z" level=debug msg="ensureSensorVolume: no volume yet = docker-slim-sensor.1.35.1" app=docker-slim command=build component=container.inspector
time="2021-05-14T17:38:44Z" level=debug msg="version.Check: http status = 200 OK" app=docker-slim
time="2021-05-14T17:38:44Z" level=debug msg="dockerutil.CreateVolumeWithData: volumeInfo = &{Name:docker-slim-sensor.1.35.1 Driver:local Mountpoint:/var/lib/docker/volumes/docker-slim-sensor.1.35.1/_data Labels:map[] Options:map[] CreatedAt:2021-05-14 17:38:44 +0000 UTC}"
time="2021-05-14T17:38:45Z" level=debug msg="dockerutil.CopyToVolume: containerID - 58348dcb61b326cabccadb9e03ba8623bc890843e1241d173f93c59075202438"
time="2021-05-14T17:38:45Z" level=debug msg="RunContainer: default exposed ports => map[docker.Port]struct {}{\"65501/tcp\":struct {}{}, \"65502/tcp\":struct {}{}}" app=docker-slim command=build component=container.inspector
cmd=build info=container status='created' name='dockerslimk_29_20210514173845' id='483c9963b9b34692828315003fc18880278fdaec0a02cfdb1d8359b63af3e461' 
time="2021-05-14T17:38:45Z" level=debug msg="RunContainer: container HostConfig.NetworkMode => default len(ports)=2" app=docker-slim command=build component=container.inspector
time="2021-05-14T17:38:45Z" level=debug msg="RunContainer: container NetworkSettings.Ports => map[docker.Port][]docker.PortBinding{\"65501/tcp\":[]docker.PortBinding{docker.PortBinding{HostIP:\"0.0.0.0\", HostPort:\"49154\"}, docker.PortBinding{HostIP:\"::\", HostPort:\"49154\"}}, \"65502/tcp\":[]docker.PortBinding{docker.PortBinding{HostIP:\"0.0.0.0\", HostPort:\"49153\"}, docker.PortBinding{HostIP:\"::\", HostPort:\"49153\"}}}" app=docker-slim command=build component=container.inspector
time="2021-05-14T17:38:45Z" level=debug msg="ipc.NewClient(172.18.0.2,65501,65502)"
time="2021-05-14T17:38:45Z" level=debug msg="channel.NewClient: connect wait timeout - 1m0s"
time="2021-05-14T17:38:45Z" level=debug msg="channel.NewClient: net.DialTimeout(tcp,172.18.0.2:65501,15s) [time=1621013925650110776]"
time="2021-05-14T17:39:00Z" level=debug msg="channel.NewClient: (dial time = 15.000319532s) - connect error = dial tcp 172.18.0.2:65501: i/o timeout"
time="2021-05-14T17:39:00Z" level=debug msg="channel.NewClient: waiting before trying to connect again..."
time="2021-05-14T17:39:02Z" level=debug msg="channel.NewClient: net.DialTimeout(tcp,172.18.0.2:65501,15s) [time=1621013942650946145]"
time="2021-05-14T17:39:17Z" level=debug msg="channel.NewClient: (dial time = 15.000454304s) - connect error = dial tcp 172.18.0.2:65501: i/o timeout"
time="2021-05-14T17:39:17Z" level=debug msg="channel.NewClient: waiting before trying to connect again..."
time="2021-05-14T17:39:19Z" level=debug msg="channel.NewClient: net.DialTimeout(tcp,172.18.0.2:65501,15s) [time=1621013959651850145]"
time="2021-05-14T17:39:34Z" level=debug msg="channel.NewClient: (dial time = 15.000622457s) - connect error = dial tcp 172.18.0.2:65501: i/o timeout"
time="2021-05-14T17:39:34Z" level=debug msg="channel.NewClient: waiting before trying to connect again..."
time="2021-05-14T17:39:36Z" level=debug msg="channel.NewClient: net.DialTimeout(tcp,172.18.0.2:65501,15s) [time=1621013976652942851]"
time="2021-05-14T17:39:51Z" level=debug msg="channel.NewClient: (dial time = 15.000435023s) - connect error = dial tcp 172.18.0.2:65501: i/o timeout"
time="2021-05-14T17:39:51Z" level=debug msg="channel.NewClient: waiting before trying to connect again..."
time="2021-05-14T17:39:53Z" level=debug msg="channel.NewClient: connect wait timeout (waited=1m8.003791712s)"
time="2021-05-14T17:39:53Z" level=error msg="channel.NewCommandClient: NewClient error = wait timeout"
time="2021-05-14T17:39:53Z" level=error msg="ipc.NewClient init error = wait timeout"
time="2021-05-14T17:39:53Z" level=fatal msg="docker-slim: failure" error="wait timeout" stack="goroutine 1 [running]:\nruntime/debug.Stack(0x74, 0x0, 0xc000078138)\n\truntime/debug/stack.go:24 +0x9f\ngithub.com/docker-slim/docker-slim/pkg/util/errutil.FailOn(0xeeb1e0, 0xc000170480)\n\tgithub.com/docker-slim/docker-slim/pkg/util/errutil/errutil.go:28 +0x54\ngithub.com/docker-slim/docker-slim/pkg/app/master/commands/build.OnCommand(0xc00000eeb8, 0xc0003a8690, 0x7fffbd716043, 0xd, 0x0, 0xc00017c630, 0xc0003d6e50, 0x0, 0x0, 0x0, ...)\n\tgithub.com/docker-slim/docker-slim/pkg/app/master/commands/build/handler.go:426 +0x1c87\ngithub.com/docker-slim/docker-slim/pkg/app/master/commands/build.glob..func1(0xc0003ca160, 0xc0003c6a00, 0xc0003c6fb0)\n\tgithub.com/docker-slim/docker-slim/pkg/app/master/commands/build/cli.go:518 +0x29c5\ngithub.com/urfave/cli.HandleAction(0xc97640, 0xe11d70, 0xc0003ca160, 0xc0003ca160, 0x0)\n\tgithub.com/urfave/cli@v1.22.4/app.go:526 +0xfd\ngithub.com/urfave/cli.Command.Run(0xdcf282, 0x5, 0x0, 0x0, 0x1441930, 0x1, 0x1, 0xe061cb, 0x6c, 0x0, ...)\n\tgithub.com/urfave/cli@v1.22.4/command.go:174 +0x58e\ngithub.com/urfave/cli.(*App).Run(0xc000380380, 0xc000030080, 0x8, 0x8, 0x0, 0x0)\n\tgithub.com/urfave/cli@v1.22.4/app.go:279 +0x7e8\ngithub.com/docker-slim/docker-slim/pkg/app/master.Run()\n\tgithub.com/docker-slim/docker-slim/pkg/app/master/app.go:15 +0x54\nmain.main()\n\tgithub.com/docker-slim/docker-slim/cmd/docker-slim/main.go:8 +0x25\n" version="linux|Transformer|1.35.1|89ddd87f009dd1e7cbd66a5494e5956c3c093edc|2021-04-27_07:10:07PM"

And here's the Dockerfile for the image being used in case that's helpful:

https://gitlab.com/megabyte-labs/dockerfile/ci-pipeline/dockerslim/-/blob/master/Dockerfile

Start with the provided .gitlab-ci.yml configuration, the docker:dind service, and the docker-slim build command; reproduce the timeout in a GitLab CI environment and inspect the debug output around the failure. Done means the demonstrated docker-slim build completes successfully against the Docker-in-Docker service without a timeout.