Setting up a mirror of a GitHub Repo using GitLab Community Edition Server

For the Community Edition of GitLab, which does not support pull mirroring directly, you can set up a workaround using a scheduled CI/CD pipeline to pull changes from the GitHub repository and push them to the GitLab repository. Here’s how you can do it:

1. Create a Personal Access Token on GitHub:

   • Go to GitHub settings.
   • Navigate to "Developer settings" -> "Personal access tokens".
   • Generate a new token with repo scope.

2. Create a GitLab CI/CD Pipeline:

   • Go to your GitLab repository.
   • Navigate to "Settings" -> "CI / CD".
   • Expand the "Variables" section and add the following variables:
     • GITHUB_REPO_URL: The URL of the GitHub repository.
     • GITHUB_TOKEN: The personal access token you created on GitHub.

3. Create a .gitlab-ci.yml File:

   • Add a .gitlab-ci.yml file to your GitLab repository with the following content:

stages:
  - mirror

mirror:
  stage: mirror
  script:
    - git config --global user.name "Your Name"
    - git config --global user.email "your.email@example.com"
    - git clone --mirror https://oauth2:${GITHUB_TOKEN}@${GITHUB_REPO_URL} repo.git
    - cd repo.git
    - git remote add gitlab https://gitlab-ci-token:${CI_JOB_TOKEN}@${CI_SERVER_HOST}/${CI_PROJECT_PATH}.git
    - git push -f gitlab --all
    - git push -f gitlab --tags
  only:
    - schedules

4. Schedule the Pipeline:
   • Go to "CI / CD" -> "Schedules".
   • Create a new pipeline schedule to run the mirroring job at your desired frequency (e.g., daily).

Explanation:

• Personal Access Token: Used to authenticate with GitHub.
• CI/CD Variables: Store sensitive information securely.
• .gitlab-ci.yml: Defines the CI/CD pipeline to clone the GitHub repository and push it to GitLab.
• Pipeline Schedule: Ensures the mirroring job runs at regular intervals.

This setup will periodically pull changes from the GitHub repository and push them to the GitLab repository, effectively mirroring the repositories.