Gitlab repository mirroring

Question

Is it possible to have gitlab set up to automatically sync (mirror) a repository hosted at another location?

At the moment, the easiest way I know of doing this involves manually pushing to the two (gitlab and the other) repository, but this is time consuming and error prone.

The greatest problem is that a mirror can resynchronize if two users concurrently push changes to the two different repositories. The best method I can come up with to prevent this issue is to ensure users can only push to one of the repositories.

Answer 1

Update Dec 2016: Mirroring is suported with GitLAb EE 8.2+: see "Repository mirroring".

As commented by Xiaodong Qi:

This answer can be simplified without using any command lines (just set it up on Gitlab repo management interface)

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Original answer (January 2013)

If your remote mirror repo is a bare repo, then you can add a post-receive hook to your gitlab-managed repo, and push to your remote repo in it.

#!/bin/bash git push --mirror [email protected]:/path/to/repo.git 

As Gitolite (used by Gitlab) mentions:

if you want to install a hook in only a few specific repositories, do it directly on the server.

which would be in:

~git/repositories/yourRepo.git/hook/post-receive 

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Caveat (Update Ocotober 2014)

Ciro Santilli points out in the comments:

Today (Q4 2014) this will fail because GitLab automatically symlinks github.com/gitlabhq/gitlab-shell/tree/… into every repository it manages.
So if you make this change, every repository you modify will try to push.
Not to mention possible conflicts when upgrading gitlab-shell, and that the current script is a ruby script, not bash (and you should not remove it!).

You could correct this by reading the current directory name and ensuring bijection between that and the remote, but I recommend people to stay far far away from those things

See (and vote for) feeadback "Automatic push to remote mirror repo after push to GitLab Repo".

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Update July 2016: I see this kind of feature added for GitLab EE (Enterprise Edition): MR 249

• Add ability to enter remote push URL under Mirror Repository settings
• Add implementation code to push to remote repository
• Add new background worker
• Show latest update date and sync errors if they exists.
• Sync remote mirror every hour.

Note that the recent Remote Mirror Repository (issues 17940) can be tricky:

I'm currently trying to shift main development of the Open Source npm modules of my company Lossless GmbH (https://www.npmjs.com/~lossless) from GitHub.com to GitLab.com

I'm importing all the repos from GitHub, however when I try to switch off Mirror Repository and switch on Remote Mirror Repository with the original GitHub URL I get an error saying:

Remote mirrors url is already in use 

Here is one of the repos this fails with: https://gitlab.com/pushrocks/npmts Edited 2 months ago

turns out, it just requires multiple steps:

• disable the Mirror Repository
• press save
• remove the URl
• press save
• then add the Remote Mirror

Answer 2

If not hosting your own GitLab, it's worth knowing GitLab.com has introduced this feature directly, without any workarounds.

1. From within a project use the gear icon to select Mirror Repository
2. Scroll down to Push to a remote repository
3. Checkmark Remote mirror repository: Automatically update the remote mirror's branches, tags, and commits from this repository every hour.
4. Enter the repository you want to update; for GitHub at least you can include your username and password in the URL, like so: https://yourgithubusername:[email protected]/agaric/guts_discuss_resource.git

Note that if you are pulling from a remote repository, it will still push on to the remote repository set here. I haven't tried it, but you should be able to push to and pull from the same repository.