

- [How To](#how-to)
- [References](#references)

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We run an internal GitLab server for our projects - this is mainly to keep our cloud CI/CD costs down but it also has the added benefit of providing an easy integration with our internal k8s deployments.

Sometimes it can also be beneficial to have some repositories mirrored to GitHub (e.g. for offsite backups, cloud integrated deploys without internal access, etc.). GitLab makes this fairly easy, as it can be setup to mirror changes on each push.

## How To

1. In GitLab, Go to `Settings > Repository`
1. Expand the `Mirroring repositories` section
1. Enter `ssh://` followed by the GitHub repository SSH URL
1. Replace the `:` with `/` after `git@github.com` in the SSH URL
1. Either get the host keys and enter them manually by selecting `Input host keys manually` or click the `Detect host keys` button
1. Switch the Auth to `SSH public key`
1. Click `Mirror repository`
1. Copy the SSH public key by clicking the Clipboard icon on the added mirrored repositories row
1. Open the repository to mirror to on GitHub
1. Go to `Settings > Deploy keys`
1. Click `Add deploy key`
1. Give it a title such as `GitLab` and paste the copied key from GitLab into the `Key` field
1. Check the `Allow write access` checkbox (required for GitLab to be able to push changes to GitHub)
1. Click `Add key`

Mirroring should now be running. All changes will be pushed to GitHub when the next commit is pushed to GitLab or when the refresh button is clicked on the Mirrored repositories row in GitLab.


## References
- [GitLab Docs: Repository mirroring](https://docs.gitlab.com/ee/user/project/repository/mirror/)
- [GitHub Docs: Managing deploy keys](https://docs.github.com/en/developers/overview/managing-deploy-keys)

Posts tagged "source control"

Mirroring a GitLab Repository to GitHub