--- stage: Package group: Package 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/#designated-technical-writers --- # GitLab Container Registry administration > - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/4040) in GitLab 8.8. > - Container Registry manifest `v1` support was added in GitLab 8.9 to support > Docker versions earlier than 1.10. With the GitLab Container Registry, every project can have its own space to store Docker images. Read more about the Docker Registry in [the Docker documentation](https://docs.docker.com/registry/introduction/). This document is the administrator's guide. To learn how to use the GitLab Container Registry, see the [user documentation](../../user/packages/container_registry/index.md). ## Enable the Container Registry **Omnibus GitLab installations** If you installed GitLab by using the Omnibus installation package, the Container Registry may or may not be available by default. The Container Registry is automatically enabled and available on your GitLab domain, port 5050 if: - You're using the built-in [Let's Encrypt integration](https://docs.gitlab.com/omnibus/settings/ssl.html#lets-encrypt-integration), and - You're using GitLab 12.5 or later. Otherwise, the Container Registry is not enabled. To enable it: - You can configure it for your [GitLab domain](#configure-container-registry-under-an-existing-gitlab-domain), or - You can configure it for [a different domain](#configure-container-registry-under-its-own-domain). The Container Registry works under HTTPS by default. You can use HTTP but it's not recommended and is beyond the scope of this document. Read the [insecure Registry documentation](https://docs.docker.com/registry/insecure/) if you want to implement this. **Installations from source** If you have installed GitLab from source: 1. You must [install Registry](https://docs.docker.com/registry/deploying/) by yourself. 1. After the installation is complete, to enable it, you must configure the Registry's settings in `gitlab.yml`. 1. Use the sample NGINX configuration file from under [`lib/support/nginx/registry-ssl`](https://gitlab.com/gitlab-org/gitlab/blob/master/lib/support/nginx/registry-ssl) and edit it to match the `host`, `port`, and TLS certificate paths. The contents of `gitlab.yml` are: ```yaml registry: enabled: true host: registry.gitlab.example.com port: 5005 api_url: http://localhost:5000/ key: config/registry.key path: shared/registry issuer: gitlab-issuer ``` Where: | Parameter | Description | | --------- | ----------- | | `enabled` | `true` or `false`. Enables the Registry in GitLab. By default this is `false`. | | `host` | The host URL under which the Registry runs and users can use. | | `port` | The port the external Registry domain listens on. | | `api_url` | The internal API URL under which the Registry is exposed. It defaults to `http://localhost:5000`. | | `key` | The private key location that is a pair of Registry's `rootcertbundle`. Read the [token auth configuration documentation](https://docs.docker.com/registry/configuration/#token). | | `path` | This should be the same directory like specified in Registry's `rootdirectory`. Read the [storage configuration documentation](https://docs.docker.com/registry/configuration/#storage). This path needs to be readable by the GitLab user, the web-server user and the Registry user. Read more in [#configure-storage-for-the-container-registry](#configure-storage-for-the-container-registry). | | `issuer` | This should be the same value as configured in Registry's `issuer`. Read the [token auth configuration documentation](https://docs.docker.com/registry/configuration/#token). | A Registry init file is not shipped with GitLab if you install it from source. Hence, [restarting GitLab](../restart_gitlab.md#installations-from-source) does not restart the Registry should you modify its settings. Read the upstream documentation on how to achieve that. At the **absolute** minimum, make sure your [Registry configuration](https://docs.docker.com/registry/configuration/#auth) has `container_registry` as the service and `https://gitlab.example.com/jwt/auth` as the realm: ```yaml auth: token: realm: https://gitlab.example.com/jwt/auth service: container_registry issuer: gitlab-issuer rootcertbundle: /root/certs/certbundle ``` CAUTION: **Caution:** If `auth` is not set up, users can pull Docker images without authentication. ## Container Registry domain configuration There are two ways you can configure the Registry's external domain. Either: - [Use the existing GitLab domain](#configure-container-registry-under-an-existing-gitlab-domain). The Registry listens on a port and reuses GitLab's TLS certificate. - [Use a completely separate domain](#configure-container-registry-under-its-own-domain) with a new TLS certificate for that domain. Because the Container Registry requires a TLS certificate, cost may be a factor. Take this into consideration before configuring the Container Registry for the first time. ### Configure Container Registry under an existing GitLab domain If the Registry is configured to use the existing GitLab domain, you can expose the Registry on a port. This way you can reuse the existing GitLab TLS certificate. If the GitLab domain is `https://gitlab.example.com` and the port to the outside world is `5050`, here is what you need to set in `gitlab.rb` or `gitlab.yml` if you are using Omnibus GitLab or installed GitLab from source respectively. Ensure you choose a port different than the one that Registry listens to (`5000` by default), otherwise conflicts occur. **Omnibus GitLab installations** 1. Your `/etc/gitlab/gitlab.rb` should contain the Registry URL as well as the path to the existing TLS certificate and key used by GitLab: ```ruby registry_external_url 'https://gitlab.example.com:5050' ``` The `registry_external_url` is listening on HTTPS under the existing GitLab URL, but on a different port. If your TLS certificate is not in `/etc/gitlab/ssl/gitlab.example.com.crt` and key not in `/etc/gitlab/ssl/gitlab.example.com.key` uncomment the lines below: ```ruby registry_nginx['ssl_certificate'] = "/path/to/certificate.pem" registry_nginx['ssl_certificate_key'] = "/path/to/certificate.key" ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. 1. Validate using: ```shell openssl s_client -showcerts -servername gitlab.example.com -connect gitlab.example.com:5050 > cacert.pem ``` If your certificate provider provides the CA Bundle certificates, append them to the TLS certificate file. **Installations from source** 1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and configure it with the following settings: ```yaml registry: enabled: true host: gitlab.example.com port: 5050 ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. 1. Make the relevant changes in NGINX as well (domain, port, TLS certificates path). Users should now be able to sign in to the Container Registry with their GitLab credentials using: ```shell docker login gitlab.example.com:5050 ``` ### Configure Container Registry under its own domain When the Registry is configured to use its own domain, you need a TLS certificate for that specific domain (for example, `registry.example.com`). You might need a wildcard certificate if hosted under a subdomain of your existing GitLab domain, for example, `registry.gitlab.example.com`. As well as manually generated SSL certificates (explained here), certificates automatically generated by Let's Encrypt are also [supported in Omnibus installs](https://docs.gitlab.com/omnibus/settings/ssl.html#host-services). Let's assume that you want the container Registry to be accessible at `https://registry.gitlab.example.com`. **Omnibus GitLab installations** 1. Place your TLS certificate and key in `/etc/gitlab/ssl/registry.gitlab.example.com.crt` and `/etc/gitlab/ssl/registry.gitlab.example.com.key` and make sure they have correct permissions: ```shell chmod 600 /etc/gitlab/ssl/registry.gitlab.example.com.* ``` 1. After the TLS certificate is in place, edit `/etc/gitlab/gitlab.rb` with: ```ruby registry_external_url 'https://registry.gitlab.example.com' ``` The `registry_external_url` is listening on HTTPS. 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. If you have a [wildcard certificate](https://en.wikipedia.org/wiki/Wildcard_certificate), you must specify the path to the certificate in addition to the URL, in this case `/etc/gitlab/gitlab.rb` looks like: ```ruby registry_nginx['ssl_certificate'] = "/etc/gitlab/ssl/certificate.pem" registry_nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/certificate.key" ``` **Installations from source** 1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and configure it with the following settings: ```yaml registry: enabled: true host: registry.gitlab.example.com ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. 1. Make the relevant changes in NGINX as well (domain, port, TLS certificates path). Users should now be able to sign in to the Container Registry using their GitLab credentials: ```shell docker login registry.gitlab.example.com ``` ## Disable Container Registry site-wide When you disable the Registry by following these steps, you do not remove any existing Docker images. This is handled by the Registry application itself. **Omnibus GitLab** 1. Open `/etc/gitlab/gitlab.rb` and set `registry['enable']` to `false`: ```ruby registry['enable'] = false ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** 1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and set `enabled` to `false`: ```yaml registry: enabled: false ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ## Disable Container Registry for new projects site-wide If the Container Registry is enabled, then it should be available on all new projects. To disable this function and let the owners of a project to enable the Container Registry by themselves, follow the steps below. **Omnibus GitLab installations** 1. Edit `/etc/gitlab/gitlab.rb` and add the following line: ```ruby gitlab_rails['gitlab_default_projects_features_container_registry'] = false ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** 1. Open `/home/git/gitlab/config/gitlab.yml`, find the `default_projects_features` entry and configure it so that `container_registry` is set to `false`: ```yaml ## Default project features settings default_projects_features: issues: true merge_requests: true wiki: true snippets: false builds: true container_registry: false ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ## Configure storage for the Container Registry You can configure the Container Registry to use various storage backends by configuring a storage driver. By default the GitLab Container Registry is configured to use the [file system driver](#use-file-system) configuration. The different supported drivers are: | Driver | Description | |------------|-------------------------------------| | filesystem | Uses a path on the local filesystem | | Azure | Microsoft Azure Blob Storage | | gcs | Google Cloud Storage | | s3 | Amazon Simple Storage Service. Be sure to configure your storage bucket with the correct [S3 Permission Scopes](https://docs.docker.com/registry/storage-drivers/s3/#s3-permission-scopes). | | swift | OpenStack Swift Object Storage | | oss | Aliyun OSS | Although most S3 compatible services (like [MinIO](https://min.io/)) should work with the Container Registry, we only guarantee support for AWS S3. Because we cannot assert the correctness of third-party S3 implementations, we can debug issues, but we cannot patch the registry unless an issue is reproducible against an AWS S3 bucket. Read more about the individual driver's configuration options in the [Docker Registry docs](https://docs.docker.com/registry/configuration/#storage). ### Use file system If you want to store your images on the file system, you can change the storage path for the Container Registry, follow the steps below. This path is accessible to: - The user running the Container Registry daemon. - The user running GitLab. All GitLab, Registry, and web server users must have access to this directory. **Omnibus GitLab installations** The default location where images are stored in Omnibus, is `/var/opt/gitlab/gitlab-rails/shared/registry`. To change it: 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby gitlab_rails['registry_path'] = "/path/to/registry/storage" ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** The default location where images are stored in source installations, is `/home/git/gitlab/shared/registry`. To change it: 1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and change the `path` setting: ```yaml registry: path: shared/registry ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ### Use object storage If you want to store your images on object storage, you can change the storage driver for the Container Registry. [Read more about using object storage with GitLab](../object_storage.md). CAUTION: **Warning:** GitLab does not back up Docker images that are not stored on the file system. Enable backups with your object storage provider if desired. **Omnibus GitLab installations** To configure the `s3` storage driver in Omnibus: 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['storage'] = { 's3' => { 'accesskey' => 's3-access-key', 'secretkey' => 's3-secret-key-for-access-key', 'bucket' => 'your-s3-bucket', 'region' => 'your-s3-region', 'regionendpoint' => 'your-s3-regionendpoint' } } ``` To avoid using static credentials, use an [IAM role](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html) and omit `accesskey` and `secretkey`. Make sure that your IAM profile follows [the permissions documented by Docker](https://docs.docker.com/registry/storage-drivers/s3/#s3-permission-scopes). ```ruby registry['storage'] = { 's3' => { 'bucket' => 'your-s3-bucket', 'region' => 'your-s3-region' } } ``` - `regionendpoint` is only required when configuring an S3 compatible service such as MinIO. It takes a URL such as `http://127.0.0.1:9000`. - `your-s3-bucket` should be the name of a bucket that exists, and can't include subdirectories. 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** Configuring the storage driver is done in the registry configuration YML file created when you [deployed your Docker registry](https://docs.docker.com/registry/deploying/). `s3` storage driver example: ```yaml storage: s3: accesskey: 's3-access-key' # Not needed if IAM role used secretkey: 's3-secret-key-for-access-key' # Not needed if IAM role used bucket: 'your-s3-bucket' region: 'your-s3-region' regionendpoint: 'your-s3-regionendpoint' cache: blobdescriptor: inmemory delete: enabled: true ``` `your-s3-bucket` should be the name of a bucket that exists, and can't include subdirectories. #### Migrate to object storage without downtime To migrate storage without stopping the Container Registry, set the Container Registry to read-only mode. On large instances, this may require the Container Registry to be in read-only mode for a while. During this time, you can pull from the Container Registry, but you cannot push. 1. Optional: To reduce the amount of data to be migrated, run the [garbage collection tool without downtime](#performing-garbage-collection-without-downtime). 1. This example uses the `aws` CLI. If you haven't configured the CLI before, you have to configure your credentials by running `sudo aws configure`. Because a non-administrator user likely can't access the Container Registry folder, ensure you use `sudo`. To check your credential configuration, run [`ls`](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/s3/ls.html) to list all buckets. ```shell sudo aws --endpoint-url https://your-object-storage-backend.com s3 ls ``` If you are using AWS as your back end, you do not need the [`--endpoint-url`](https://docs.aws.amazon.com/cli/latest/reference/#options). 1. Copy initial data to your S3 bucket, for example with the `aws` CLI [`cp`](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/s3/cp.html) or [`sync`](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/s3/sync.html) command. Make sure to keep the `docker` folder as the top-level folder inside the bucket. ```shell sudo aws --endpoint-url https://your-object-storage-backend.com s3 sync registry s3://mybucket ``` TIP: **Tip:** If you have a lot of data, you may be able to improve performance by [running parallel sync operations](https://aws.amazon.com/premiumsupport/knowledge-center/s3-improve-transfer-sync-command/). 1. To perform the final data sync, [put the Container Registry in `read-only` mode](#performing-garbage-collection-without-downtime) and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure). 1. Sync any changes since the initial data load to your S3 bucket and delete files that exist in the destination bucket but not in the source: ```shell sudo aws --endpoint-url https://your-object-storage-backend.com s3 sync registry s3://mybucket --delete --dryrun ``` After verifying the command performs as expected, remove the [`--dryrun`](https://docs.aws.amazon.com/cli/latest/reference/s3/sync.html) flag and run the command. DANGER: **Warning:** The [`--delete`](https://docs.aws.amazon.com/cli/latest/reference/s3/sync.html) flag deletes files that exist in the destination but not in the source. If you swap the source and destination, all data in the Registry is deleted. 1. Verify all Container Registry files have been uploaded to object storage by looking at the file count returned by these two commands: ```shell sudo find registry -type f | wc -l ``` ```shell sudo aws --endpoint-url https://your-object-storage-backend.com s3 ls s3://mybucket --recursive | wc -l ``` The output of these commands should match, except for the content in the `_uploads` directories and sub-directories. 1. Configure your registry to [use the S3 bucket for storage](#use-object-storage). 1. For the changes to take effect, set the Registry back to `read-write` mode and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure). ### Disable redirect for storage driver By default, users accessing a registry configured with a remote backend are redirected to the default backend for the storage driver. For example, registries can be configured using the `s3` storage driver, which redirects requests to a remote S3 bucket to alleviate load on the GitLab server. However, this behavior is undesirable for registries used by internal hosts that usually can't access public servers. To disable redirects and [proxy download](../object_storage.md#proxy-download), set the `disable` flag to true as follows. This makes all traffic always go through the Registry service. This results in improved security (less surface attack as the storage backend is not publicly accessible), but worse performance (all traffic is redirected via the service). **Omnibus GitLab installations** 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['storage'] = { 's3' => { 'accesskey' => 's3-access-key', 'secretkey' => 's3-secret-key-for-access-key', 'bucket' => 'your-s3-bucket', 'region' => 'your-s3-region', 'regionendpoint' => 'your-s3-regionendpoint' }, 'redirect' => { 'disable' => true } } ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** 1. Add the `redirect` flag to your registry configuration YML file: ```yaml storage: s3: accesskey: 'AKIAKIAKI' secretkey: 'secret123' bucket: 'gitlab-registry-bucket-AKIAKIAKI' region: 'your-s3-region' regionendpoint: 'your-s3-regionendpoint' redirect: disable: true cache: blobdescriptor: inmemory delete: enabled: true ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ### Storage limitations Currently, there is no storage limitation, which means a user can upload an infinite amount of Docker images with arbitrary sizes. This setting should be configurable in future releases. ## Change the registry's internal port The Registry server listens on localhost at port `5000` by default, which is the address for which the Registry server should accept connections. In the examples below we set the Registry's port to `5001`. **Omnibus GitLab** 1. Open `/etc/gitlab/gitlab.rb` and set `registry['registry_http_addr']`: ```ruby registry['registry_http_addr'] = "localhost:5001" ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** 1. Open the configuration file of your Registry server and edit the [`http:addr`](https://docs.docker.com/registry/configuration/#http) value: ```yaml http: addr: localhost:5001 ``` 1. Save the file and restart the Registry server. ## Disable Container Registry per project If Registry is enabled in your GitLab instance, but you don't need it for your project, you can disable it from your project's settings. Read the user guide on how to achieve that. ## Use an external container registry with GitLab as an auth endpoint If you use an external container registry, some features associated with the container registry may be unavailable or have [inherent risks](../../user/packages/container_registry/index.md#use-with-external-container-registries). **Omnibus GitLab** You can use GitLab as an auth endpoint with an external container registry. 1. Open `/etc/gitlab/gitlab.rb` and set necessary configurations: ```ruby gitlab_rails['registry_enabled'] = true gitlab_rails['registry_api_url'] = "http://localhost:5000" gitlab_rails['registry_issuer'] = "omnibus-gitlab-issuer" ``` `gitlab_rails['registry_enabled'] = true` is needed to enable GitLab's Container Registry features and authentication endpoint. GitLab's bundled Container Registry service does not start, even with this enabled. 1. A certificate-key pair is required for GitLab and the external container registry to communicate securely. You need to create a certificate-key pair, configuring the external container registry with the public certificate and configuring GitLab with the private key. To do that, add the following to `/etc/gitlab/gitlab.rb`: ```ruby # registry['internal_key'] should contain the contents of the custom key # file. Line breaks in the key file should be marked using `\n` character # Example: registry['internal_key'] = "---BEGIN RSA PRIVATE KEY---\nMIIEpQIBAA\n" # Optionally define a custom file for Omnibus GitLab to write the contents # of registry['internal_key'] to. gitlab_rails['registry_key_path'] = "/custom/path/to/registry-key.key" ``` Each time reconfigure is executed, the file specified at `registry_key_path` gets populated with the content specified by `internal_key`. If no file is specified, Omnibus GitLab defaults it to `/var/opt/gitlab/gitlab-rails/etc/gitlab-registry.key` and populates it. 1. To change the container registry URL displayed in the GitLab Container Registry pages, set the following configurations: ```ruby gitlab_rails['registry_host'] = "registry.gitlab.example.com" gitlab_rails['registry_port'] = "5005" ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** 1. Open `/home/git/gitlab/config/gitlab.yml`, and edit the configuration settings under `registry`: ```yaml ## Container Registry registry: enabled: true host: "registry.gitlab.example.com" port: "5005" api_url: "http://localhost:5000" path: /var/opt/gitlab/gitlab-rails/shared/registry key: /var/opt/gitlab/gitlab-rails/certificate.key issuer: omnibus-gitlab-issuer ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ## Configure Container Registry notifications You can configure the Container Registry to send webhook notifications in response to events happening within the registry. Read more about the Container Registry notifications configuration options in the [Docker Registry notifications documentation](https://docs.docker.com/registry/notifications/). You can configure multiple endpoints for the Container Registry. **Omnibus GitLab installations** To configure a notification endpoint in Omnibus: 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['notifications'] = [ { 'name' => 'test_endpoint', 'url' => 'https://gitlab.example.com/notify', 'timeout' => '500ms', 'threshold' => 5, 'backoff' => '1s', 'headers' => { "Authorization" => ["AUTHORIZATION_EXAMPLE_TOKEN"] } } ] ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **Installations from source** Configuring the notification endpoint is done in your registry configuration YML file created when you [deployed your Docker registry](https://docs.docker.com/registry/deploying/). Example: ```yaml notifications: endpoints: - name: alistener disabled: false url: https://my.listener.com/event headers: timeout: 500 threshold: 5 backoff: 1000 ``` ## Run the Cleanup policy now To reduce the amount of [Container Registry disk space used by a given project](../troubleshooting/gitlab_rails_cheat_sheet.md#registry-disk-space-usage-by-project), administrators can clean up image tags and [run garbage collection](#container-registry-garbage-collection). To remove image tags by running the cleanup policy, run the following commands in the [GitLab Rails console](../troubleshooting/navigating_gitlab_via_rails_console.md): ```ruby # Numeric ID of the project whose container registry should be cleaned up P = # Numeric ID of a developer, maintainer or owner in that project U = # Get required details / objects user = User.find_by_id(U) project = Project.find_by_id(P) policy = ContainerExpirationPolicy.find_by(project_id: P) # Loop through each container repository project.container_repositories.find_each do |repo| puts repo.attributes # Start the tag cleanup puts Projects::ContainerRepository::CleanupTagsService.new(project, user, policy.attributes.except("created_at", "updated_at")).execute(repo) end ``` You can also [run cleanup on a schedule](../../user/packages/container_registry/index.md#cleanup-policy). ## Container Registry garbage collection Container Registry can use considerable amounts of disk space. To clear up some unused layers, the registry includes a garbage collect command. GitLab offers a set of APIs to manipulate the Container Registry and aid the process of removing unused tags. Currently, this is exposed using the API, but in the future, these controls should migrate to the GitLab interface. Project maintainers can [delete Container Registry tags in bulk](../../api/container_registry.md#delete-registry-repository-tags-in-bulk) periodically based on their own criteria, however, this alone does not recycle data, it only unlinks tags from manifests and image blobs. To recycle the Container Registry data in the whole GitLab instance, you can use the built-in command provided by `gitlab-ctl`. Prerequisites: - You must have installed GitLab by using an Omnibus package or the [cloud native chart](https://docs.gitlab.com/charts/charts/registry/#garbage-collection). - You must set the Registry to [read-only mode](#performing-garbage-collection-without-downtime). Running garbage collection causes downtime for the Container Registry. When you run this command on an instance in an environment where another instances is still writing to the Registry storage, referenced manifests are removed. ### Understanding the content-addressable layers Consider the following example, where you first build the image: ```shell # This builds a image with content of sha256:111111 docker build -t my.registry.com/my.group/my.project:latest . docker push my.registry.com/my.group/my.project:latest ``` Now, you do overwrite `:latest` with a new version: ```shell # This builds a image with content of sha256:222222 docker build -t my.registry.com/my.group/my.project:latest . docker push my.registry.com/my.group/my.project:latest ``` Now, the `:latest` tag points to manifest of `sha256:222222`. However, due to the architecture of registry, this data is still accessible when pulling the image `my.registry.com/my.group/my.project@sha256:111111`, even though it is no longer directly accessible via the `:latest` tag. ### Recycling unused tags > [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/987) in Omnibus GitLab 8.12. Before you run the built-in command, note the following: - The built-in command stops the registry before it starts the garbage collection. - The garbage collect command takes some time to complete, depending on the amount of data that exists. - If you changed the location of registry configuration file, you must specify its path. - After the garbage collection is done, the registry should start automatically. If you did not change the default location of the configuration file, run: ```shell sudo gitlab-ctl registry-garbage-collect ``` This command will take some time to complete, depending on the amount of layers you have stored. If you changed the location of the Container Registry `config.yml`: ```shell sudo gitlab-ctl registry-garbage-collect /path/to/config.yml ``` You may also [remove all untagged manifests and unreferenced layers](#removing-untagged-manifests-and-unreferenced-layers), although this is a way more destructive operation, and you should first understand the implications. ### Removing untagged manifests and unreferenced layers > [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/3097) in Omnibus GitLab 11.10. DANGER: **Warning:** This is a destructive operation. The GitLab Container Registry follows the same default workflow as Docker Distribution: retain untagged manifests and all layers, even ones that are not referenced directly. All content can be accessed by using context addressable identifiers. However, in most workflows, you don't care about untagged manifests and old layers if they are not directly referenced by a tagged manifest. The `registry-garbage-collect` command supports the `-m` switch to allow you to remove all unreferenced manifests and layers that are not directly accessible via `tag`: ```shell sudo gitlab-ctl registry-garbage-collect -m ``` Without the `-m` flag, the Container Registry only removes layers that are not referenced by any manifest, tagged or not. Since this is a way more destructive operation, this behavior is disabled by default. You are likely expecting this way of operation, but before doing that, ensure that you have backed up all registry data. ### Performing garbage collection without downtime > [Introduced](https://gitlab.com/gitlab-org/omnibus-gitlab/-/merge_requests/764) in GitLab 8.8. You can perform garbage collection without stopping the Container Registry by putting it in read-only mode and by not using the built-in command. On large instances this could require Container Registry to be in read-only mode for a while. During this time, you will be able to pull from the Container Registry, but you will not be able to push. By default, the [registry storage path](#configure-storage-for-the-container-registry) is `/var/opt/gitlab/gitlab-rails/shared/registry`. To enable the read-only mode: 1. In `/etc/gitlab/gitlab.rb`, specify the read-only mode: ```ruby registry['storage'] = { 'filesystem' => { 'rootdirectory' => "" }, 'maintenance' => { 'readonly' => { 'enabled' => true } } } ``` 1. Save and reconfigure GitLab: ```shell sudo gitlab-ctl reconfigure ``` This will set the Container Registry into the read only mode. 1. Next, trigger one of the garbage collect commands: ```shell # Recycling unused tags sudo /opt/gitlab/embedded/bin/registry garbage-collect /var/opt/gitlab/registry/config.yml # Removing unused layers not referenced by manifests sudo /opt/gitlab/embedded/bin/registry garbage-collect -m /var/opt/gitlab/registry/config.yml ``` This will start the garbage collection, which might take some time to complete. 1. Once done, in `/etc/gitlab/gitlab.rb` change it back to read-write mode: ```ruby registry['storage'] = { 'filesystem' => { 'rootdirectory' => "" }, 'maintenance' => { 'readonly' => { 'enabled' => false } } } ``` 1. Save and reconfigure GitLab: ```shell sudo gitlab-ctl reconfigure ``` ### Running the garbage collection on schedule Ideally, you want to run the garbage collection of the registry regularly on a weekly basis at a time when the registry is not being in-use. The simplest way is to add a new crontab job that it will run periodically once a week. Create a file under `/etc/cron.d/registry-garbage-collect`: ```shell SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin # Run every Sunday at 04:05am 5 4 * * 0 root gitlab-ctl registry-garbage-collect ``` You may want to add the `-m` flag to [remove untagged manifests and unreferenced layers](#removing-untagged-manifests-and-unreferenced-layers). ## Troubleshooting Before diving in to the following sections, here's some basic troubleshooting: 1. Check to make sure that the system clock on your Docker client and GitLab server have been synchronized (e.g. via NTP). 1. If you are using an S3-backed Registry, double check that the IAM permissions and the S3 credentials (including region) are correct. See [the sample IAM policy](https://docs.docker.com/registry/storage-drivers/s3/) for more details. 1. Check the Registry logs (e.g. `/var/log/gitlab/registry/current`) and the GitLab production logs for errors (e.g. `/var/log/gitlab/gitlab-rails/production.log`). You may be able to find clues there. ### Using self-signed certificates with Container Registry If you're using a self-signed certificate with your Container Registry, you might encounter issues during the CI jobs like the following: ```plaintext Error response from daemon: Get registry.example.com/v1/users/: x509: certificate signed by unknown authority ``` The Docker daemon running the command expects a cert signed by a recognized CA, thus the error above. While GitLab doesn't support using self-signed certificates with Container Registry out of the box, it is possible to make it work by [instructing the Docker daemon to trust the self-signed certificates](https://docs.docker.com/registry/insecure/#use-self-signed-certificates), mounting the Docker daemon and setting `privileged = false` in the GitLab Runner `config.toml` file. Setting `privileged = true` takes precedence over the Docker daemon: ```toml [runners.docker] image = "ruby:2.6" privileged = false volumes = ["/var/run/docker.sock:/var/run/docker.sock", "/cache"] ``` Additional information about this: [issue 18239](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/18239). ### `unauthorized: authentication required` when pushing large images Example error: ```shell docker push gitlab.example.com/myproject/docs:latest The push refers to a repository [gitlab.example.com/myproject/docs] 630816f32edb: Preparing 530d5553aec8: Preparing ... 4b0bab9ff599: Waiting d1c800db26c7: Waiting 42755cf4ee95: Waiting unauthorized: authentication required ``` GitLab has a default token expiration of 5 minutes for the registry. When pushing larger images, or images that take longer than 5 minutes to push, users may encounter this error. Administrators can increase the token duration in **Admin area > Settings > CI/CD > Container Registry > Authorization token duration (minutes)**. ### AWS S3 with the GitLab registry error when pushing large images When using AWS S3 with the GitLab registry, an error may occur when pushing large images. Look in the Registry log for the following error: ```plaintext level=error msg="response completed with error" err.code=unknown err.detail="unexpected EOF" err.message="unknown error" ``` To resolve the error specify a `chunksize` value in the Registry configuration. Start with a value between `25000000` (25MB) and `50000000` (50MB). **For Omnibus installations** 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['storage'] = { 's3' => { 'accesskey' => 'AKIAKIAKI', 'secretkey' => 'secret123', 'bucket' => 'gitlab-registry-bucket-AKIAKIAKI', 'chunksize' => 25000000 } } ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **For installations from source** 1. Edit `config/gitlab.yml`: ```yaml storage: s3: accesskey: 'AKIAKIAKI' secretkey: 'secret123' bucket: 'gitlab-registry-bucket-AKIAKIAKI' chunksize: 25000000 ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ### Supporting older Docker clients As of GitLab 11.9, we began shipping version 2.7.1 of the Docker container registry, which disables the schema1 manifest by default. If you are still using older Docker clients (1.9 or older), you may experience an error pushing images. See [omnibus-4145](https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/4145) for more details. You can add a configuration option for backwards compatibility. **For Omnibus installations** 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['compatibility_schema1_enabled'] = true ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **For installations from source** 1. Edit the YML configuration file you created when you [deployed the registry](https://docs.docker.com/registry/deploying/). Add the following snippet: ```yaml compatibility: schema1: enabled: true ``` 1. Restart the registry for the changes to take affect. ### Docker connection error A Docker connection error can occur when there are special characters in either the group, project or branch name. Special characters can include: - Leading underscore - Trailing hyphen/dash - Double hyphen/dash To get around this, you can [change the group path](../../user/group/index.md#changing-a-groups-path), [change the project path](../../user/project/settings/index.md#renaming-a-repository) or change the branch name. Another option is to create a [push rule](../../push_rules/push_rules.md) to prevent this at the instance level. ### Image push errors When getting errors or "retrying" loops in an attempt to push an image but `docker login` works fine, there is likely an issue with the headers forwarded to the registry by NGINX. The default recommended NGINX configurations should handle this, but it might occur in custom setups where the SSL is offloaded to a third party reverse proxy. This problem was discussed in a [Docker project issue](https://github.com/docker/distribution/issues/970) and a simple solution would be to enable relative URLs in the Registry. **For Omnibus installations** 1. Edit `/etc/gitlab/gitlab.rb`: ```ruby registry['env'] = { "REGISTRY_HTTP_RELATIVEURLS" => true } ``` 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. **For installations from source** 1. Edit the YML configuration file you created when you [deployed the registry](https://docs.docker.com/registry/deploying/). Add the following snippet: ```yaml http: relativeurls: true ``` 1. Save the file and [restart GitLab](../restart_gitlab.md#installations-from-source) for the changes to take effect. ### Enable the Registry debug server The optional debug server can be enabled by setting the registry debug address in your `gitlab.rb` configuration. ```ruby registry['debug_addr'] = "localhost:5001" ``` After adding the setting, [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) to apply the change. Use curl to request debug output from the debug server: ```shell curl localhost:5001/debug/health curl localhost:5001/debug/vars ``` ### Advanced Troubleshooting We will use a concrete example in the past to illustrate how to diagnose a problem with the S3 setup. #### Unexpected 403 error during push A user attempted to enable an S3-backed Registry. The `docker login` step went fine. However, when pushing an image, the output showed: ```plaintext The push refers to a repository [s3-testing.myregistry.com:5050/root/docker-test/docker-image] dc5e59c14160: Pushing [==================================================>] 14.85 kB 03c20c1a019a: Pushing [==================================================>] 2.048 kB a08f14ef632e: Pushing [==================================================>] 2.048 kB 228950524c88: Pushing 2.048 kB 6a8ecde4cc03: Pushing [==> ] 9.901 MB/205.7 MB 5f70bf18a086: Pushing 1.024 kB 737f40e80b7f: Waiting 82b57dbc5385: Waiting 19429b698a22: Waiting 9436069b92a3: Waiting error parsing HTTP 403 response body: unexpected end of JSON input: "" ``` This error is ambiguous, as it's not clear whether the 403 is coming from the GitLab Rails application, the Docker Registry, or something else. In this case, since we know that since the login succeeded, we probably need to look at the communication between the client and the Registry. The REST API between the Docker client and Registry is [described here](https://docs.docker.com/registry/spec/api/). Normally, one would just use Wireshark or tcpdump to capture the traffic and see where things went wrong. However, since all communications between Docker clients and servers are done over HTTPS, it's a bit difficult to decrypt the traffic quickly even if you know the private key. What can we do instead? One way would be to disable HTTPS by setting up an [insecure Registry](https://docs.docker.com/registry/insecure/). This could introduce a security hole and is only recommended for local testing. If you have a production system and can't or don't want to do this, there is another way: use mitmproxy, which stands for Man-in-the-Middle Proxy. #### mitmproxy [mitmproxy](https://mitmproxy.org/) allows you to place a proxy between your client and server to inspect all traffic. One wrinkle is that your system needs to trust the mitmproxy SSL certificates for this to work. The following installation instructions assume you are running Ubuntu: 1. [Install mitmproxy](https://docs.mitmproxy.org/stable/overview-installation/). 1. Run `mitmproxy --port 9000` to generate its certificates. Enter CTRL-C to quit. 1. Install the certificate from `~/.mitmproxy` to your system: ```shell sudo cp ~/.mitmproxy/mitmproxy-ca-cert.pem /usr/local/share/ca-certificates/mitmproxy-ca-cert.crt sudo update-ca-certificates ``` If successful, the output should indicate that a certificate was added: ```shell Updating certificates in /etc/ssl/certs... 1 added, 0 removed; done. Running hooks in /etc/ca-certificates/update.d....done. ``` To verify that the certificates are properly installed, run: ```shell mitmproxy --port 9000 ``` This will run mitmproxy on port `9000`. In another window, run: ```shell curl --proxy http://localhost:9000 https://httpbin.org/status/200 ``` If everything is set up correctly, you will see information on the mitmproxy window and no errors from the curl commands. #### Running the Docker daemon with a proxy For Docker to connect through a proxy, you must start the Docker daemon with the proper environment variables. The easiest way is to shutdown Docker (e.g. `sudo initctl stop docker`) and then run Docker by hand. As root, run: ```shell export HTTP_PROXY="http://localhost:9000" export HTTPS_PROXY="https://localhost:9000" docker daemon --debug ``` This will launch the Docker daemon and proxy all connections through mitmproxy. #### Running the Docker client Now that we have mitmproxy and Docker running, we can attempt to sign in and push a container image. You may need to run as root to do this. For example: ```shell docker login s3-testing.myregistry.com:5050 docker push s3-testing.myregistry.com:5050/root/docker-test/docker-image ``` In the example above, we see the following trace on the mitmproxy window: ![mitmproxy output from Docker](img/mitmproxy-docker.png) The above image shows: - The initial PUT requests went through fine with a 201 status code. - The 201 redirected the client to the S3 bucket. - The HEAD request to the AWS bucket reported a 403 Unauthorized. What does this mean? This strongly suggests that the S3 user does not have the right [permissions to perform a HEAD request](https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html). The solution: check the [IAM permissions again](https://docs.docker.com/registry/storage-drivers/s3/). Once the right permissions were set, the error will go away.