gitlab-org--gitlab-foss/doc/user/project/import/github.md

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---
type: reference, howto
stage: Manage
group: Import
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
---
# Import your project from GitHub to GitLab
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Using the importer, you can import your GitHub repositories to GitLab.com or to
your self-managed GitLab instance.
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## Overview
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The following aspects of a project are imported:
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- Repository description (GitLab.com & 7.7+)
- Git repository data (GitLab.com & 7.7+)
- Issues (GitLab.com & 7.7+)
- Pull requests (GitLab.com & 8.4+)
- Wiki pages (GitLab.com & 8.4+)
- Milestones (GitLab.com & 8.7+)
- Labels (GitLab.com & 8.7+)
- Release note descriptions (GitLab.com & 8.12+)
- Pull request review comments (GitLab.com & 10.2+)
- Pull request reviews (GitLab.com & 13.7+)
- Pull request "merged by" information (GitLab.com & 13.7+)
- Regular issue and pull request comments
- [Git Large File Storage (LFS) Objects](../../../topics/git/lfs/index.md)
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References to pull requests and issues are preserved (GitLab.com & 8.7+), and
each imported repository maintains visibility level unless that [visibility
level is restricted](../../../public_access/public_access.md#restricting-the-use-of-public-or-internal-projects),
in which case it defaults to the default project visibility.
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The namespace is a user or group in GitLab, such as `gitlab.com/janedoe` or `gitlab.com/customer-success`. You can do some bulk actions to move projects to different namespaces in the rails console.
This process does not migrate or import any types of groups or organizations from GitHub to GitLab.
### Use cases
The steps you take depend on whether you are importing from GitHub.com or GitHub Enterprise, as well as whether you are importing to GitLab.com or self-managed GitLab instance.
- If you're importing to GitLab.com, you can alternatively import GitHub repositories
using a [personal access token](#using-a-github-token). We do not recommend
this method, as it does not associate all user activity (such as issues and
pull requests) with matching GitLab users.
- If you're importing to a self-managed GitLab instance, you can alternatively use the
[GitHub Rake task](../../../administration/raketasks/github_import.md) to import
projects without the constraints of a [Sidekiq](../../../development/sidekiq_style_guide.md) worker.
- If you're importing from GitHub Enterprise to your self-managed GitLab instance, you must first enable
[GitHub integration](../../../integration/github.md). However, you cannot import projects from GitHub Enterprise to GitLab.com.
- If you're importing from GitHub.com to your self-managed GitLab instance, you do not need to set up GitHub integration.
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## How it works
When issues and pull requests are being imported, the importer attempts to find their GitHub authors and
assignees in the database of the GitLab instance (note that pull requests are called "merge requests" in GitLab).
For this association to succeed, each GitHub author and assignee in the repository
must meet one of the following conditions prior to the import:
- Have previously logged in to a GitLab account using the GitHub icon.
- Have a GitHub account with a publicly visible
[primary email address](https://docs.github.com/en/rest/reference/users#get-a-user)
on their profile that matches their GitLab account's primary or secondary email address.
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If a user referenced in the project is not found in the GitLab database, the project creator (typically the user
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that initiated the import process) is set as the author/assignee, but a note on the issue mentioning the original
GitHub author is added.
The importer creates any new namespaces (groups) if they do not exist, or, if the namespace is taken, the
repository is imported under the namespace of the user who initiated the import process. The namespace/repository
name can also be edited, with the proper permissions.
The importer will also import branches on forks of projects related to open pull requests. These branches will be
imported with a naming scheme similar to `GH-SHA-username/pull-request-number/fork-name/branch`. This may lead to
a discrepancy in branches compared to those of the GitHub repository.
For additional technical details, you can refer to the
[GitHub Importer](../../../development/github_importer.md "Working with the GitHub importer")
developer documentation.
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For an overview of the import process, see the video [Migrating from GitHub to GitLab](https://youtu.be/VYOXuOg9tQI).
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## Import your GitHub repository into GitLab
### Using the GitHub integration
Before you begin, ensure that any GitHub users who you want to map to GitLab users have either:
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- A GitLab account that has logged in using the GitHub icon
\- or -
- A GitLab account with an email address that matches the [publicly visible email address](https://docs.github.com/en/rest/reference/users#get-a-user) in the profile of the GitHub user
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User-matching attempts occur in that order, and if a user is not identified either way, the activity is associated with
the user account that is performing the import.
NOTE:
If you are using a self-managed GitLab instance or if you are importing from GitHub Enterprise, this process requires that you have configured
[GitHub integration](../../../integration/github.md).
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1. From the top navigation bar, click **+** and select **New project**.
1. Select the **Import project** tab and then select **GitHub**.
1. Select the first button to **List your GitHub repositories**. You are redirected to a page on [GitHub](https://github.com) to authorize the GitLab application.
1. Click **Authorize GitlabHQ**. You are redirected back to the GitLab Import page and all of your GitHub repositories are listed.
1. Continue on to [selecting which repositories to import](#selecting-which-repositories-to-import).
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### Using a GitHub token
NOTE:
Using a personal access token to import projects is not recommended. If you are a GitLab.com user,
you can use a personal access token to import your project from GitHub, but this method cannot
associate all user activity (such as issues and pull requests) with matching GitLab users.
If you are an administrator of a self-managed GitLab instance or if you are importing from
GitHub Enterprise, you cannot use a personal access token.
The [GitHub integration method (above)](#using-the-github-integration) is recommended for all users.
Read more in the [How it works](#how-it-works) section.
If you are not using the GitHub integration, you can still perform an authorization with GitHub to grant GitLab access your repositories:
1. Go to <https://github.com/settings/tokens/new>
1. Enter a token description.
1. Select the repository scope.
1. Click **Generate token**.
1. Copy the token hash.
1. Go back to GitLab and provide the token to the GitHub importer.
1. Hit the **List Your GitHub Repositories** button and wait while GitLab reads your repositories' information.
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Once done, you'll be taken to the importer page to select the repositories to import.
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### Selecting which repositories to import
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After you have authorized access to your GitHub repositories, you are redirected to the GitHub importer page and
your GitHub repositories are listed.
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1. By default, the proposed repository namespaces match the names as they exist in GitHub, but based on your permissions,
you can choose to edit these names before you proceed to import any of them.
1. Select the **Import** button next to any number of repositories, or select **Import all repositories**. Additionally,
you can filter projects by name. If filter is applied, **Import all repositories** only imports matched repositories.
1. The **Status** column shows the import status of each repository. You can choose to leave the page open and it will
update in real-time or you can return to it later.
1. Once a repository has been imported, click its GitLab path to open its GitLab URL.
![GitHub importer page](img/import_projects_from_github_importer_v12_3.png)
## Mirroring and pipeline status sharing
Depending on your GitLab tier, [repository mirroring](../repository/repository_mirroring.md) can be set up to keep
your imported repository in sync with its GitHub copy.
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Additionally, you can configure GitLab to send pipeline status updates back GitHub with the
[GitHub Project Integration](../integrations/github.md). **(PREMIUM)**
If you import your project using [CI/CD for external repository](../../../ci/ci_cd_for_external_repos/index.md), then both
of the above are automatically configured. **(PREMIUM)**
## Improving the speed of imports on self-managed instances
NOTE:
Administrator access to the GitLab server is required.
Rewrite the GitHub importer from scratch Prior to this MR there were two GitHub related importers: * Github::Import: the main importer used for GitHub projects * Gitlab::GithubImport: importer that's somewhat confusingly used for importing Gitea projects (apparently they have a compatible API) This MR renames the Gitea importer to Gitlab::LegacyGithubImport and introduces a new GitHub importer in the Gitlab::GithubImport namespace. This new GitHub importer uses Sidekiq for importing multiple resources in parallel, though it also has the ability to import data sequentially should this be necessary. The new code is spread across the following directories: * lib/gitlab/github_import: this directory contains most of the importer code such as the classes used for importing resources. * app/workers/gitlab/github_import: this directory contains the Sidekiq workers, most of which simply use the code from the directory above. * app/workers/concerns/gitlab/github_import: this directory provides a few modules that are included in every GitHub importer worker. == Stages The import work is divided into separate stages, with each stage importing a specific set of data. Stages will schedule the work that needs to be performed, followed by scheduling a job for the "AdvanceStageWorker" worker. This worker will periodically check if all work is completed and schedule the next stage if this is the case. If work is not yet completed this worker will reschedule itself. Using this approach we don't have to block threads by calling `sleep()`, as doing so for large projects could block the thread from doing any work for many hours. == Retrying Work Workers will reschedule themselves whenever necessary. For example, hitting the GitHub API's rate limit will result in jobs rescheduling themselves. These jobs are not processed until the rate limit has been reset. == User Lookups Part of the importing process involves looking up user details in the GitHub API so we can map them to GitLab users. The old importer used an in-memory cache, but this obviously doesn't work when the work is spread across different threads. The new importer uses a Redis cache and makes sure we only perform API/database calls if absolutely necessary. Frequently used keys are refreshed, and lookup misses are also cached; removing the need for performing API/database calls if we know we don't have the data we're looking for. == Performance & Models The new importer in various places uses raw INSERT statements (as generated by `Gitlab::Database.bulk_insert`) instead of using Rails models. This allows us to bypass any validations and callbacks, drastically reducing the number of SQL queries and Gitaly RPC calls necessary to import projects. To ensure the code produces valid data the corresponding tests check if the produced rows are valid according to the model validation rules.
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For large projects it may take a while to import all data. To reduce the time necessary, you can increase the number of
Sidekiq workers that process the following queues:
Rewrite the GitHub importer from scratch Prior to this MR there were two GitHub related importers: * Github::Import: the main importer used for GitHub projects * Gitlab::GithubImport: importer that's somewhat confusingly used for importing Gitea projects (apparently they have a compatible API) This MR renames the Gitea importer to Gitlab::LegacyGithubImport and introduces a new GitHub importer in the Gitlab::GithubImport namespace. This new GitHub importer uses Sidekiq for importing multiple resources in parallel, though it also has the ability to import data sequentially should this be necessary. The new code is spread across the following directories: * lib/gitlab/github_import: this directory contains most of the importer code such as the classes used for importing resources. * app/workers/gitlab/github_import: this directory contains the Sidekiq workers, most of which simply use the code from the directory above. * app/workers/concerns/gitlab/github_import: this directory provides a few modules that are included in every GitHub importer worker. == Stages The import work is divided into separate stages, with each stage importing a specific set of data. Stages will schedule the work that needs to be performed, followed by scheduling a job for the "AdvanceStageWorker" worker. This worker will periodically check if all work is completed and schedule the next stage if this is the case. If work is not yet completed this worker will reschedule itself. Using this approach we don't have to block threads by calling `sleep()`, as doing so for large projects could block the thread from doing any work for many hours. == Retrying Work Workers will reschedule themselves whenever necessary. For example, hitting the GitHub API's rate limit will result in jobs rescheduling themselves. These jobs are not processed until the rate limit has been reset. == User Lookups Part of the importing process involves looking up user details in the GitHub API so we can map them to GitLab users. The old importer used an in-memory cache, but this obviously doesn't work when the work is spread across different threads. The new importer uses a Redis cache and makes sure we only perform API/database calls if absolutely necessary. Frequently used keys are refreshed, and lookup misses are also cached; removing the need for performing API/database calls if we know we don't have the data we're looking for. == Performance & Models The new importer in various places uses raw INSERT statements (as generated by `Gitlab::Database.bulk_insert`) instead of using Rails models. This allows us to bypass any validations and callbacks, drastically reducing the number of SQL queries and Gitaly RPC calls necessary to import projects. To ensure the code produces valid data the corresponding tests check if the produced rows are valid according to the model validation rules.
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- `github_importer`
- `github_importer_advance_stage`
Rewrite the GitHub importer from scratch Prior to this MR there were two GitHub related importers: * Github::Import: the main importer used for GitHub projects * Gitlab::GithubImport: importer that's somewhat confusingly used for importing Gitea projects (apparently they have a compatible API) This MR renames the Gitea importer to Gitlab::LegacyGithubImport and introduces a new GitHub importer in the Gitlab::GithubImport namespace. This new GitHub importer uses Sidekiq for importing multiple resources in parallel, though it also has the ability to import data sequentially should this be necessary. The new code is spread across the following directories: * lib/gitlab/github_import: this directory contains most of the importer code such as the classes used for importing resources. * app/workers/gitlab/github_import: this directory contains the Sidekiq workers, most of which simply use the code from the directory above. * app/workers/concerns/gitlab/github_import: this directory provides a few modules that are included in every GitHub importer worker. == Stages The import work is divided into separate stages, with each stage importing a specific set of data. Stages will schedule the work that needs to be performed, followed by scheduling a job for the "AdvanceStageWorker" worker. This worker will periodically check if all work is completed and schedule the next stage if this is the case. If work is not yet completed this worker will reschedule itself. Using this approach we don't have to block threads by calling `sleep()`, as doing so for large projects could block the thread from doing any work for many hours. == Retrying Work Workers will reschedule themselves whenever necessary. For example, hitting the GitHub API's rate limit will result in jobs rescheduling themselves. These jobs are not processed until the rate limit has been reset. == User Lookups Part of the importing process involves looking up user details in the GitHub API so we can map them to GitLab users. The old importer used an in-memory cache, but this obviously doesn't work when the work is spread across different threads. The new importer uses a Redis cache and makes sure we only perform API/database calls if absolutely necessary. Frequently used keys are refreshed, and lookup misses are also cached; removing the need for performing API/database calls if we know we don't have the data we're looking for. == Performance & Models The new importer in various places uses raw INSERT statements (as generated by `Gitlab::Database.bulk_insert`) instead of using Rails models. This allows us to bypass any validations and callbacks, drastically reducing the number of SQL queries and Gitaly RPC calls necessary to import projects. To ensure the code produces valid data the corresponding tests check if the produced rows are valid according to the model validation rules.
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For an optimal experience, it's recommended having at least 4 Sidekiq processes (each running a number of threads equal
to the number of CPU cores) that *only* process these queues. It's also recommended that these processes run on separate
servers. For 4 servers with 8 cores this means you can import up to 32 objects (e.g., issues) in parallel.
Rewrite the GitHub importer from scratch Prior to this MR there were two GitHub related importers: * Github::Import: the main importer used for GitHub projects * Gitlab::GithubImport: importer that's somewhat confusingly used for importing Gitea projects (apparently they have a compatible API) This MR renames the Gitea importer to Gitlab::LegacyGithubImport and introduces a new GitHub importer in the Gitlab::GithubImport namespace. This new GitHub importer uses Sidekiq for importing multiple resources in parallel, though it also has the ability to import data sequentially should this be necessary. The new code is spread across the following directories: * lib/gitlab/github_import: this directory contains most of the importer code such as the classes used for importing resources. * app/workers/gitlab/github_import: this directory contains the Sidekiq workers, most of which simply use the code from the directory above. * app/workers/concerns/gitlab/github_import: this directory provides a few modules that are included in every GitHub importer worker. == Stages The import work is divided into separate stages, with each stage importing a specific set of data. Stages will schedule the work that needs to be performed, followed by scheduling a job for the "AdvanceStageWorker" worker. This worker will periodically check if all work is completed and schedule the next stage if this is the case. If work is not yet completed this worker will reschedule itself. Using this approach we don't have to block threads by calling `sleep()`, as doing so for large projects could block the thread from doing any work for many hours. == Retrying Work Workers will reschedule themselves whenever necessary. For example, hitting the GitHub API's rate limit will result in jobs rescheduling themselves. These jobs are not processed until the rate limit has been reset. == User Lookups Part of the importing process involves looking up user details in the GitHub API so we can map them to GitLab users. The old importer used an in-memory cache, but this obviously doesn't work when the work is spread across different threads. The new importer uses a Redis cache and makes sure we only perform API/database calls if absolutely necessary. Frequently used keys are refreshed, and lookup misses are also cached; removing the need for performing API/database calls if we know we don't have the data we're looking for. == Performance & Models The new importer in various places uses raw INSERT statements (as generated by `Gitlab::Database.bulk_insert`) instead of using Rails models. This allows us to bypass any validations and callbacks, drastically reducing the number of SQL queries and Gitaly RPC calls necessary to import projects. To ensure the code produces valid data the corresponding tests check if the produced rows are valid according to the model validation rules.
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Reducing the time spent in cloning a repository can be done by increasing network throughput, CPU capacity, and disk
performance (e.g., by using high performance SSDs) of the disks that store the Git repositories (for your GitLab instance).
Increasing the number of Sidekiq workers will *not* reduce the time spent cloning repositories.