Documentation

For anybody coming across this looking for an example .gitlab-ci.yml, check this out, it's based on the lakedrops pipeline above but works standalone:

collect-config:
  stage: deploy
  before_script:
    - git config --global user.email $GITLAB_USER_EMAIL
    - git config --global user.name "${GITLAB_USER_NAME}"
    - |
      apt-get update >/dev/null
      apt-get -y --no-install-recommends install >/dev/null rsync openssh-client
  script:
    # Setup SSH identity with artifact repo access.
    - eval $(ssh-agent -s)
    # https://stackoverflow.com/a/57774253/1483861
    - cat "$SERVER_PRIVATE_KEY" | ssh-add - > /dev/null
    - mkdir -p ~/.ssh
    - chmod 0700 ~/.ssh
    - echo -e "HOST *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config
    # Copy exported config from server.
    - rsync -r -e ssh user@site.com:/tmp/cae/ /tmp/cc-${CI_JOB_ID}
    # https://stackoverflow.com/a/50163888/1483861
    - git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.com/company/site/project.git
    - cd project
    - git checkout -b cc-${CI_JOB_ID} HEAD
    # https://gitlab.lakedrops.com/gitlab-ci-cd/drupal/-/blob/main/data-handling-ng.yml
    - |
      function collectDir() {
        CURRENT=$(pwd)
        mkdir -p $1
        cd $1
        find . -type d -exec mkdir -p "$1/{}" \;
        find . -type f -name '.*' -delete -exec sh -c "echo {}|sed -r 's!./.!$2/!g'|xargs rm" \;
        find . -type f -exec cp "$1/{}" "$2/{}" \;
        cd "${CURRENT}"
        rm -rf $1
      }
    - CURRENT=$(pwd)
    - collectDir "/tmp/cc-${CI_JOB_ID}/config_split" "${CURRENT}/config/override"
    - collectDir "/tmp/cc-${CI_JOB_ID}/language" "${CURRENT}/config/default/sync/language"
    - collectDir "/tmp/cc-${CI_JOB_ID}" "${CURRENT}/config/sync"
    - git status > /tmp/gitstatus.log
    - EC=0
    - grep "nothing to commit, working tree clean" /tmp/gitstatus.log || EC=$?
    - if [[ $EC -eq 0 ]]; then exit 0; fi
    - git add config/*
    - git commit -am "Config change on server."
    # https://stackoverflow.com/a/73394648/1483861
    - git remote set-url --push origin "https://oauth2:$ACCESS_TOKEN@gitlab.com/company/site/project.git"
    # https://stackoverflow.com/a/58327480/1483861
    - git push -o ci.skip -o merge_request.create -o merge_request.target=main origin cc-${CI_JOB_ID}
  cache: {}
  only:
    refs:
      - triggers

Nice, thanks @charginghawk. 2 questions though:

• What image has been used, assuming that this is a docker runner? If so, adding that in the task as well would make this really self-contained.
• The line apt-get -y --no-install-recommends install >/dev/null rsync openssh-client seems to be wrong, the pipe instruction should probably be at the end of the line.

It's the ruby:3.1 image, just because that's Gitlab's default container image:

https://about.gitlab.com/blog/2022/12/13/new-default-container-image-git...

That apt-get line does look weird, I copied it from another pipeline, but it works! Apparently redirections can appear anywhere in the command (I've changed it in my comment above anyway):

https://unix.stackexchange.com/a/670206/164453