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dockerdockerfilegitlab-cigit-clone

Modern way to git clone a repository while building a Docker image to the GitLab Container Registry

There seem to be much information around about this, but I cannot find a well described use-case with a modern approach (that is, without leaving traces or exposing credentials in the process).

Let's assume I am working from within GitLab group. Inside such a group there are 2 repositories, A and B.

I'd like to build a docker image to the GitLab Container Registry of project B (or even the one of the highest-level group itself).

Project B needs project A, which is only available from its repository, so currently my Dockerfile looks something like this,

# Set the base image
FROM ubuntu:18.04

# Install git
RUN apt-get -y update && apt-get install -y git

# Clone project
RUN GITLAB_GROUP=group_name git clone git@gitlab.com:$GITLAB_GROUP/A.git # for SSH
RUN GITLAB_GROUP=group_name git clone https://gitlab.com/$GITLAB_GROUP/A.git # for HTTP

[...]

(This of course cannot work as it is since there are no access permissions from within the Dockerfile.)

While the .gitlab-ci.yml would be at least something like the following,

build image:
  image: docker:20.10.17
  services:
    - docker:20.10.17-dind
  rules:
    - if: $CI_PIPELINE_SOURCE == "schedule"
  script:
    - echo $CI_REGISTRY_PASSWORD | docker login -u $CI_REGISTRY_USER $CI_REGISTRY --password-stdin
    - docker build -t $CI_REGISTRY_IMAGE .
    - docker push $CI_REGISTRY_IMAGE
Solution

  • The most efficient way would be to use gitsubmodules and then set the GIT_SUBMODULE_STRATEGY

    variables:
  GIT_SUBMODULE_STRATEGY: recursive

    That way the runner pulls the repository for you.