How I mirror my GitHub repositories on GitLab (thanks to Framagit)

For more than 10 years, I use git and I publish my open-source projects on GitHub. The platform is great, its tooling too. But I don’t know what tomorrow will bring, especially for a service from Microsoft.

Thus, I prefer not to put all my eggs in one basket. So, some months ago I looked after an open-source alternative. I didn’t want to rely only on my local repositories or on a self-hosted service. Of course, GitLab was one of the first to come to mind, but I needed a managed service.

I already use Heptapod at work (GitLab with Mercurial support), but in a personal context I mostly rely on Framasoft. So, I finally chose to create an account on Framagit. But once it’s done, how to backup my repositories?

Create a mirror repo with a GitLab push remote

There is a GitLab Mirror option, but I want to rely on a lower layer. Thus, on my main computer, I have GitHub/ and GitLab/ folders. In the first, I simply clone my repositories. In the second, I do the same using the --mirror flag. As stated in the official git documentation:

Set up a mirror of the source repository. This implies --bare. Compared to --bare, --mirror not only maps local branches of the source to local branches of the target, it maps all refs (including remote-tracking branches, notes etc.) and sets up a refspec configuration such that all these refs are overwritten by a git remote update in the target repository.

Then, I create an empty GitLab repository and use it as a push remote:

git clone --mirror https://github.com/user/repo.git
cd repo.git
git remote set-url --push gitlab git@framagit.org:user/repo.git

Fetch/Push the content (via an alias)

To sync your mirror from its local folder, you only need to:

git fetch --prune && git push --mirror

You can use an alias declared in .bashrc or .zshrc to perform this sync action on multiple repositories from a single command:

function sync_git() {
  GITLAB_DIR="/path/to/gitlab/directory"

  # Declare an array of repo subdirectories
  declare -a REPO_DIRS=("repo1" "repo2" "repo3")

  # Go in each of them and sync
  for repo_dir in "${REPO_DIRS[@]}"; do
      echo "Entering ${GITLAB_DIR}/${repo_dir}.git"
      cd "${GITLAB_DIR}/${repo_dir}.git"

      git fetch --prune && git push --mirror

      echo
  done

  printf "%s \e[32m✓\e[0m\n" "Script completed"
}

After saving the file, reload your shell with exec bash or exec zsh.

Go further

You can launch this command manually or on a regular basis through CRON for example (but you’ll need a git authentication not asking for a passphrase).

For my needs, I use this script in a more complete alias to update my system and tools (brew, bun, npm, rustup, v, etc.), with additional commands to clone some repositories I need to have locally, up to date.

The most important

Don’t forget to support Framasoft. This is how their great actions are funded, along with services such as Framagit.