Docker-in-docker build DNS resolution problems

[theRDVN]

Hi everyone,

I’m trying to use gitlab-ci-local on macOS to test GitLab CI pipelines locally, which is a perfect tool for this use case.

My setup:

• The pipeline starts a docker:24.x.x image.
• Inside the job, it executes docker build . command to build a Java application using maven:3.9.x-eclipse-temurin-21.
• The Java build requires both:
  • Internal Maven repository.
  • Public Maven repositories (repo.maven.apache.org, etc.).

The problem:

When running the pipeline locally via gitlab-ci-local on macOS:

1. The job container itself can resolve internal and external hostnames (ping/nslookup works).
2. However, the docker build step inside the job container fails to resolve:
   2a. Internal Maven repo
   2b. Public Maven repos

I have tried:
• --add-host internal.maven.repo:IP → internal host resolves, but public Maven repositories fail.
• Attempting to override /etc/resolv.conf → fails because it’s read-only inside build containers.
• --network=host → fails on macOS BuildKit (network.host is not allowed).

It seems that docker-in-docker on macOS cannot inherit the network/DNS configuration from the job container, which makes it impossible for the build container to access both internal or external dependencies.

I’m looking for guidance on:
• How to make docker builds inside gitlab-ci-local pipelines on macOS resolve both internal and external DNS correctly.
• Any known workarounds or best practices for this situation.

Pipeline template looks something like this (its the first ste:

build:
  image: docker.io/docker:24.0.7
  stage: build
  interruptible: true
  before_script:
    - export VERSION=$(cat .version)
    - export TAG=$IMAGE_TAG
    - echo "Container image tag $TAG"
  script:
    - until docker info &>/dev/null ; do sleep 2 && echo "Testing  Docker deamon connection (dind)" ; done
    - echo $DOCKER_PASSWORD | docker login -u $DOCKER_USER --password-stdin $DOCKER_REPOSITORY
    - docker build --pull -t $DOCKER_REPOSITORY/${IMAGE_NAME}:$TAG --build-arg "BRANCH_NAME=$CI_COMMIT_REF_NAME" --build-arg "VERSION=$VERSION" --build-arg "BUILD=$IMAGE_TAG" --build-arg "MAVEN_SETTING=$MAVEN_SETTING" .

Dockerfile is standard build for Java App using mvn install which uses docker.io/maven:3.9.6-eclipse-temurin-21 for building.

When running mvn install i get error about resolving internal DNS with error Temporary failure in name resolution. After trying to fix this with --add-host internal.maven.repo:IP flag as i mentioned earlier, i get error about not being able to resolve public maven repository, so i cannot test the later stages of pipeline - deploy and test.
And just for clarification - all works when running via GitlabCI runner...

If there is anything else I can add, please let me know, i will try to provide the best information I can give.

Thanks in advance for any help or suggestions!