Jorisvandijk.com

Future full-stack developer

Mirroring a Git Repository

I use Git for backing up purposes as well as for its awesome version control. I use Git for personal projects and I use Git for school projects. I have several repositories across several Git hosts. My main one is currently at Codeberg. For school I cannot use that one, as school requires me to use theirs. As I don't want to host everything I make for school on a host that I won't have access to anymore after I'm done with school, I will want to have a copy on my "own" host.

So, what's the easiest way to update once and have changes be pushed to both repositories? Mirroring a repository. The following steps will show how to do this from Gitlab to Github. You can also do this from Gitlab to Gitlab or Github to Github. Or, well any git host to another, though some steps or naming conventions might differ slightly.

The steps to take

  1. On GitHub create a new repository, to which the repository on GitLab will mirror.

  2. Copy the SSH link you'd use to clone the repository. This should be git@github.com:USERNAME/REPOSITORY.git

  3. From within a GitLab project use the gear icon to select Repository and there go to Mirroring repositories and click Expand.

  4. In the Git repository URL field, paste the SSH link copied in step 2.

  5. Add ssh:// in front of the link and replace the : with a /.

  6. At Mirror direction select Push (We're pushing from GitLab to GitHub).

  7. Click the Detect host keys button.

  8. Set Authentication method to SSH Public key.

  9. Click the green Mirror Repository button.

  10. Click the Copy SSH public key button, which looks like a clipboard.

  11. Go back to GitHub.

  12. Go to Settings and there click on Deploy Keys.

  13. Click the Add deploy key button on the top right of the page.

  14. In the Title field add a title to identify the key. Something like GitLab.

  15. In the Key field, paste the key you copied in step 10. Don't edit anything you just pasted.

  16. Tick the Allow write access checkbox and click the Add key button.

  17. Go back to GitLab.

  18. Click the Update now button, whick looks like two arrows.

  19. Give it some time, then refresh the page and check if the Last successful update field changes from Never to x minutes ago.

  20. You can double check by going back to GitHub and refreshing the Deploy keys page too. Never used should change to Last used within the last week — Read/write.

  21. Profit!