diff options
author | Achilleas Pipinellis <axil@gitlab.com> | 2018-06-04 12:15:48 +0300 |
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committer | Achilleas Pipinellis <axil@gitlab.com> | 2018-06-04 13:15:42 +0300 |
commit | 2d7aef1397c08f6fade604cdecfe542b7088ac26 (patch) | |
tree | 53019c8ff423a8947482f536a203efb25852fbbb /doc/workflow | |
parent | 8197c756b13be9189eebb649fdb61e7aebb7978d (diff) |
Port repository mirroring from EE
Diffstat (limited to 'doc/workflow')
11 files changed, 245 insertions, 5 deletions
diff --git a/doc/workflow/repository_mirroring.md b/doc/workflow/repository_mirroring.md index dbe63144e38..aaddbe4fbf5 100644 --- a/doc/workflow/repository_mirroring.md +++ b/doc/workflow/repository_mirroring.md @@ -1,6 +1,6 @@ # Repository mirroring -Repository Mirroring is a way to mirror repositories from external sources. +Repository mirroring is a way to mirror repositories from external sources. It can be used to mirror all branches, tags, and commits that you have in your repository. @@ -34,13 +34,200 @@ A few things/limitations to consider: - The Git LFS objects will not be synced. You'll need to push/pull them manually. -## Use-case +## Use cases +- You migrated to GitLab but still need to keep your project in another source. + In that case, you can simply set it up to mirror to GitLab (pull) and all the + essential history of commits, tags and branches will be available in your + GitLab instance. - You have old projects in another source that you don't use actively anymore, but don't want to remove for archiving purposes. In that case, you can create a push mirror so that your active GitLab repository can push its changes to the old location. +## Pulling from a remote repository **[STARTER]** + +>[Introduced][ee-51] in GitLab Enterprise Edition 8.2. + +You can set up a repository to automatically have its branches, tags, and commits +updated from an upstream repository. This is useful when a repository you're +interested in is located on a different server, and you want to be able to +browse its content and its activity using the familiar GitLab interface. + +When creating a new project, you can enable repository mirroring when you choose +to import the repository from "Any repo by URL". Enter the full URL of the Git +repository to pull from and click on the **Mirror repository** checkbox. + +![New project](repository_mirroring/repository_mirroring_new_project.png) + +For an existing project, you can set up mirror pulling by visiting your project's +**Settings ➔ Repository** and searching for the "Pull from a remote repository" +section. Check the "Mirror repository" box and hit **Save changes** at the bottom. +You have a few options to choose from one being the user who will be the author +of all events in the activity feed that are the result of an update. This user +needs to have at least [master access][perms] to the project. Another option is +whether you want to trigger builds for mirror updates. + +![Pull settings](repository_mirroring/repository_mirroring_pull_settings.png) + +Since the repository on GitLab functions as a mirror of the upstream repository, +you are advised not to push commits directly to the repository on GitLab. +Instead, any commits should be pushed to the upstream repository, and will end +up in the GitLab repository automatically within a certain period of time +or when a [forced update](#forcing-an-update) is initiated. + +If you do manually update a branch in the GitLab repository, the branch will +become diverged from upstream, and GitLab will no longer automatically update +this branch to prevent any changes from being lost. + +![Diverged branch](repository_mirroring/repository_mirroring_diverged_branch.png) + +### Trigger update using API **[STARTER]** + +>[Introduced][ee-3453] in GitLab Enterprise Edition 10.3. + +Pull mirroring uses polling to detect new branches and commits added upstream, +often many minutes afterwards. If you notify GitLab by [API][pull-api], updates +will be pulled immediately. + +Read the [Pull Mirror Trigger API docs][pull-api]. + +### Pull only protected branches **[STARTER]** + +>[Introduced][ee-3326] in GitLab Enterprise Edition 10.3. + +You can choose to only pull the protected branches from your remote repository to GitLab. + +To use this option go to your project's repository settings page under pull mirror. + +### Overwrite diverged branches **[STARTER]** + +>[Introduced][ee-4559] in GitLab Enterprise Edition 10.6. + +You can choose to always update your local branch with the remote version even +if your local version has diverged from the remote. + +To use this option go to your project's repository settings page under pull mirror. + +### Hard failure **[STARTER]** + +>[Introduced][ee-3117] in GitLab Enterprise Edition 10.2. + +Once a mirror gets retried 14 times in a row, it will get marked as hard failed, +this will become visible in either the project main dashboard or in the +pull mirror settings page. + +![Hard failed mirror main notice](repository_mirroring/repository_mirroring_hard_failed_main.png) + +![Hard failed mirror settings notice](repository_mirroring/repository_mirroring_hard_failed_settings.png) + +When a project is hard failed, it will no longer get picked up for mirroring. +A user can resume the project mirroring again by either [forcing an update](#forcing-an-update) +or by changing the import URL in repository settings. + +### SSH authentication **[STARTER]** + +> [Introduced][ee-2551] in GitLab Starter 9.5 + +If you're mirroring over SSH (i.e., an `ssh://` URL), you can authenticate using +password-based authentication, just as over HTTPS, but you can also use public +key authentication. This is often more secure than password authentication, +especially when the source repository supports [Deploy Keys][deploy-key]. + +To get started, navigate to **Settings ➔ Repository ➔ Pull from a remote repository**, +enable mirroring (if not already enabled) and enter an `ssh://` URL. + +> **NOTE**: SCP-style URLs, e.g., `git@example.com:group/project.git`, are not +supported at this time. + +Entering the URL adds two features to the page - `Fingerprints` and +`SSH public key authentication`: + +![Pull settings for SSH](repository_mirroring/repository_mirroring_pull_settings_for_ssh.png) + +SSH authentication is mutual. You have to prove to the server that you're +allowed to access the repository, but the server also has to prove to *you* that +it's who it claims to be. You provide your credentials as a password or public +key. The server that the source repository resides on provides its credentials +as a "host key", the fingerprint of which needs to be verified manually. + +Press the `Detect host keys` button. GitLab will fetch the host keys from the +server, and display the fingerprints to you: + +![Detect SSH host keys](repository_mirroring/repository_mirroring_detect_host_keys.png) + +You now need to verify that the fingerprints are those you expect. GitLab.com +and other code hosting sites publish their fingerprints in the open for you +to check: + +* [AWS CodeCommit](http://docs.aws.amazon.com/codecommit/latest/userguide/regions.html#regions-fingerprints) +* [Bitbucket](https://confluence.atlassian.com/bitbucket/use-the-ssh-protocol-with-bitbucket-cloud-221449711.html#UsetheSSHprotocolwithBitbucketCloud-KnownhostorBitbucket%27spublickeyfingerprints) +* [GitHub](https://help.github.com/articles/github-s-ssh-key-fingerprints/) +* [GitLab.com](https://about.gitlab.com/gitlab-com/settings/#ssh-host-keys-fingerprints) +* [Launchpad](https://help.launchpad.net/SSHFingerprints) +* [Savannah](http://savannah.gnu.org/maintenance/SshAccess/) +* [SourceForge](https://sourceforge.net/p/forge/documentation/SSH%20Key%20Fingerprints/) + +Other providers will vary. If you're running on-premises GitLab, or otherwise +have access to the source server, you can securely gather the key fingerprints: + +``` +$ cat /etc/ssh/ssh_host*pub | ssh-keygen -E md5 -l -f - +256 MD5:f4:28:9f:23:99:15:21:1b:bf:ed:1f:8e:a0:76:b2:9d root@example.com (ECDSA) +256 MD5:e6:eb:45:8a:3c:59:35:5f:e9:5b:80:12:be:7e:22:73 root@example.com (ED25519) +2048 MD5:3f:72:be:3d:62:03:5c:62:83:e8:6e:14:34:3a:85:1d root@example.com (RSA) +``` + +(You may need to exclude `-E md5` for some older versions of SSH). + +If you're an SSH expert and already have a `known_hosts` file you'd like to use +unaltered, then you can skip these steps. Just press the "Show advanced" button +and paste in the file contents: + +![Advanced SSH host key management](repository_mirroring/repository_mirroring_pull_advanced_host_keys.png) + +Once you've **carefully verified** that all the fingerprints match your trusted +source, you can press `Save changes`. This will record the host keys, along with +the person who verified them (you!) and the date: + +![SSH host keys submitted](repository_mirroring/repository_mirroring_ssh_host_keys_verified.png) + +When pulling changes from the source repository, GitLab will now check that at +least one of the stored host keys matches before connecting. This can prevent +malicious code from being injected into your mirror, or your password being +stolen! + +To use SSH public key authentication, you'll also need to choose that option +from the authentication methods dropdown. GitLab will generate a 4096-bit RSA +key and display the public component of that key to you: + +![SSH public key authentication](repository_mirroring/repository_mirroring_ssh_public_key_authentication.png) + +You then need to add the public SSH key to the source repository configuration. +If the source is hosted on GitLab, you should add it as a [Deploy Key][deploy-key]. +Other sources may require you to add the key to your user's `authorized_keys` +file - just paste the entire `ssh-rsa AAA.... user@host` block into the file on +its own line and save it. + +Once the public key is set up on the source repository, press `Save changes` and your +mirror will begin working. + +If you need to change the key at any time, you can press the `Regenerate key` +button to do so. You'll have to update the source repository with the new key +to keep the mirror running. + +### How it works + +Once you activate the pull mirroring feature, the mirror will be inserted into +a queue. A scheduler will start every minute and schedule a fixed amount of +mirrors for update, based on the configured maximum capacity. + +If the mirror successfully updates it will be enqueued once again with a small +backoff period. + +If the mirror fails (eg: branch diverged from upstream), the project's backoff +period will be penalized each time it fails up to a maximum amount of time. + ## Pushing to a remote repository **[STARTER]** >[Introduced](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/249) in @@ -83,7 +270,7 @@ To use this option go to your project's repository settings page under push mirr To set up a mirror from GitLab to GitHub, you need to follow these steps: 1. Create a [GitHub personal access token](https://help.github.com/articles/creating-a-personal-access-token-for-the-command-line/) with the "public_repo" box checked: - + ![edit personal access token GitHub](repository_mirroring/repository_mirroring_github_edit_personal_access_token.png) 1. Fill in the "Git repository URL" with the personal access token replacing the password `https://GitHubUsername:GitHubPersonalAccessToken@github.com/group/project.git`: @@ -94,7 +281,7 @@ To set up a mirror from GitLab to GitHub, you need to follow these steps: 1. And either wait or trigger the "Update Now" button: ![update now](repository_mirroring/repository_mirroring_gitlab_push_to_a_remote_repository_update_now.png) - + ## Forcing an update While mirrors are scheduled to update automatically, you can always force an update @@ -105,7 +292,60 @@ by using the **Update now** button which is exposed in various places: - in the tags page - in the **Mirror repository** settings page +## Bidirectional mirroring + +CAUTION: **Warning:** +There is no bidirectional support without conflicts. If you +configure a repository to pull and push to a second remote, there is no +guarantee that it will update correctly on both remotes. If you configure +a repository for bidirectional mirroring, you should consider when conflicts +occur who and how they will be resolved. + +Rewriting any mirrored commit on either remote will cause conflicts and +mirroring to fail. This can be prevented by [only pulling protected branches]( +#pull-only-protected-branches) and [only pushing protected branches]( +#push-only-protected-branches). You should protect the branches you wish to +mirror on both remotes to prevent conflicts caused by rewriting history. + +Bidirectional mirroring also creates a race condition where commits to the same +branch in close proximity will cause conflicts. The race condition can be +mitigated by reducing the mirroring delay by using a Push event webhook to +trigger an immediate pull to GitLab. Push mirroring from GitLab is rate limited +to once per minute when only push mirroring protected branches. + +It may be possible to implement a locking mechanism using the server-side +`pre-receive` hook to prevent the race condition. Read about [configuring +custom Git hooks][hooks] on the GitLab server. + +### Mirroring with Perforce via GitFusion + +CAUTION: **Warning:** +Bidirectional mirroring should not be used as a permanent +configuration. There is no bidirectional mirroring without conflicts. +Refer to [Migrating from Perforce Helix][perforce] for alternative migration +approaches. + +GitFusion provides a Git interface to Perforce which can be used by GitLab to +bidirectionally mirror projects with GitLab. This may be useful in some +situations when migrating from Perforce to GitLab where overlapping Perforce +workspaces cannot be migrated simultaneously to GitLab. + +If using mirroring with Perforce you should only mirror protected branches. +Perforce will reject any pushes that rewrite history. It is recommended that +only the fewest number of branches are mirrored due to the performance +limitations of GitFusion. + +[ee-51]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/51 +[ee-2551]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2551 +[ee-3117]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3117 +[ee-3326]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3326 [ee-3350]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3350 +[ee-3453]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3453 +[ee-4559]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4559 [ce-18715]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18715 [perms]: ../user/permissions.md - +[hooks]: ../administration/custom_hooks.md +[deploy-key]: ../ssh/README.md#deploy-keys +[webhook]: ../user/project/integrations/webhooks.md#push-events +[pull-api]: ../api/projects.md#start-the-pull-mirroring-process-for-a-project +[perforce]: ../user/project/import/perforce.md diff --git a/doc/workflow/repository_mirroring/repository_mirroring_detect_host_keys.png b/doc/workflow/repository_mirroring/repository_mirroring_detect_host_keys.png Binary files differnew file mode 100644 index 00000000000..333648942f8 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_detect_host_keys.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_diverged_branch.png b/doc/workflow/repository_mirroring/repository_mirroring_diverged_branch.png Binary files differnew file mode 100644 index 00000000000..45c9bce0889 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_diverged_branch.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_main.png b/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_main.png Binary files differnew file mode 100644 index 00000000000..99d429a1802 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_main.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_settings.png b/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_settings.png Binary files differnew file mode 100644 index 00000000000..0ab07afa3cc --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_hard_failed_settings.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_new_project.png b/doc/workflow/repository_mirroring/repository_mirroring_new_project.png Binary files differnew file mode 100644 index 00000000000..43bf304838f --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_new_project.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_pull_advanced_host_keys.png b/doc/workflow/repository_mirroring/repository_mirroring_pull_advanced_host_keys.png Binary files differnew file mode 100644 index 00000000000..5da5a7436bb --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_pull_advanced_host_keys.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_pull_settings.png b/doc/workflow/repository_mirroring/repository_mirroring_pull_settings.png Binary files differnew file mode 100644 index 00000000000..4b9085302a1 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_pull_settings.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_pull_settings_for_ssh.png b/doc/workflow/repository_mirroring/repository_mirroring_pull_settings_for_ssh.png Binary files differnew file mode 100644 index 00000000000..8c2efdafa43 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_pull_settings_for_ssh.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_ssh_host_keys_verified.png b/doc/workflow/repository_mirroring/repository_mirroring_ssh_host_keys_verified.png Binary files differnew file mode 100644 index 00000000000..93f3a532a0e --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_ssh_host_keys_verified.png diff --git a/doc/workflow/repository_mirroring/repository_mirroring_ssh_public_key_authentication.png b/doc/workflow/repository_mirroring/repository_mirroring_ssh_public_key_authentication.png Binary files differnew file mode 100644 index 00000000000..6997ad511d9 --- /dev/null +++ b/doc/workflow/repository_mirroring/repository_mirroring_ssh_public_key_authentication.png |