Reduce Container Registry Storage

Container registries become large over time without cleanup. When a large number of images or tags are added:

  • Fetching the list of available tags or images becomes slower.
  • They take up a large amount of storage space on the server.

We recommend deleting unnecessary images and tags, and setting up a cleanup policy to automatically manage your container registry usage.

Check Container Registry Storage Use

The Usage Quotas page (Settings > Usage Quotas > Storage) displays storage usage for Packages, which includes Container Registry, however, the storage is not being calculated.

Cleanup policy

Version history
  • Introduced in GitLab 12.8.
  • Renamed from “expiration policy” to “cleanup policy” in GitLab 13.2.

The cleanup policy is a scheduled job you can use to remove tags from the Container Registry. For the project where it’s defined, tags matching the regex pattern are removed. The underlying layers and images remain.

To delete the underlying layers and images that aren’t associated with any tags, administrators can use garbage collection with the -m switch.

Enable the cleanup policy

Cleanup policies can be run on all projects, with these exceptions:

  • For self-managed GitLab instances, the project must have been created in GitLab 12.8 or later. However, an administrator can enable the cleanup policy for all projects (even those created before 12.8) in GitLab application settings by setting container_expiration_policies_enable_historic_entries to true. Alternatively, you can execute the following command in the Rails console:

    ApplicationSetting.last.update(container_expiration_policies_enable_historic_entries: true)
    

    There are performance risks with enabling it for all projects, especially if you are using an external registry.

  • For self-managed GitLab instances, you can enable or disable the cleanup policy for a specific project.

    To enable it:

    Feature.enable(:container_expiration_policies_historic_entry, Project.find(<project id>))
    

    To disable it:

    Feature.disable(:container_expiration_policies_historic_entry, Project.find(<project id>))
    
caution
For performance reasons, enabled cleanup policies are automatically disabled for projects on GitLab.com that don’t have a container image.

How the cleanup policy works

The cleanup policy collects all tags in the Container Registry and excludes tags until only the tags to be deleted remain.

The cleanup policy searches for images based on the tag name. Support for the full path has not yet been implemented, but would allow you to clean up dynamically-named tags.

The cleanup policy:

  1. Collects all tags for a given repository in a list.
  2. Excludes the tag named latest from the list.
  3. Evaluates the name_regex (tags to expire), excluding non-matching names from the list.
  4. Excludes from the list any tags matching the name_regex_keep value (tags to preserve).
  5. Excludes any tags that do not have a manifest (not part of the options in the UI).
  6. Orders the remaining tags by created_date.
  7. Excludes from the list the N tags based on the keep_n value (Number of tags to retain).
  8. Excludes from the list the tags more recent than the older_than value (Expiration interval).
  9. Finally, the remaining tags in the list are deleted from the Container Registry.
caution
On GitLab.com, the execution time for the cleanup policy is limited, and some of the tags may remain in the Container Registry after the policy runs. The next time the policy runs, the remaining tags are included, so it may take multiple runs for all tags to be deleted.
caution
GitLab self-managed installs support for third-party container registries that comply with the Docker Registry HTTP API V2 specification. However, this specification does not include a tag delete operation. Therefore, when interacting with third-party container registries, GitLab uses a workaround to delete tags. See the related issue for more information. Due to possible implementation variations, this workaround is not guaranteed to work with all third-party registries in the same predictable way. If you use the GitLab Container Registry, this workaround is not required because we implemented a special tag delete operation. In this case, you can expect cleanup policies to be consistent and predictable.

Create a cleanup policy

You can create a cleanup policy in the API or the UI.

To create a cleanup policy in the UI:

  1. For your project, go to Settings > Packages & Registries.
  2. Expand the Clean up image tags section.
  3. Complete the fields.

    Field Description
    Toggle Turn the policy on or off.
    Run cleanup How often the policy should run.
    Keep the most recent How many tags to always keep for each image.
    Keep tags matching The regex pattern that determines which tags to preserve. The latest tag is always preserved. For all tags, use .*. See other regex pattern examples.
    Remove tags older than Remove only tags older than X days.
    Remove tags matching The regex pattern that determines which tags to remove. This value cannot be blank. For all tags, use .*. See other regex pattern examples.
  4. Click Save.

Depending on the interval you chose, the policy is scheduled to run.

note
If you edit the policy and click Save again, the interval is reset.

Regex pattern examples

Cleanup policies use regex patterns to determine which tags should be preserved or removed, both in the UI and the API.

Regex patterns are automatically surrounded with \A and \Z anchors. Do not include any \A, \Z, ^ or $ token in the regex patterns as they are not necessary.

Here are examples of regex patterns you may want to use:

  • Match all tags:

    .*
    

    This is the default value for the expiration regex.

  • Match tags that start with v:

    v.+
    
  • Match only the tag named main:

    main
    
  • Match tags that are either named or start with release:

    release.*
    
  • Match tags that either start with v, are named main, or begin with release:

    (?:v.+|main|release.*)
    

Set cleanup limits to conserve resources

Version history
  • Introduced in GitLab 13.9.
  • It’s deployed behind a feature flag, disabled by default.
  • It’s enabled on GitLab.com.
  • It’s not recommended for production use.
  • To use it in GitLab self-managed instances, ask a GitLab administrator to enable it.

Cleanup policies are executed as a background process. This process is complex, and depending on the number of tags to delete, the process can take time to finish.

To prevent server resource starvation, the following application settings are available:

  • container_registry_expiration_policies_worker_capacity. The maximum number of cleanup workers running concurrently. This must be greater than 1. We recommend starting with a low number and increasing it after monitoring the resources used by the background workers.
  • container_registry_delete_tags_service_timeout. The maximum time, in seconds, that the cleanup process can take to delete a batch of tags.
  • container_registry_cleanup_tags_service_max_list_size. The maximum number of tags that can be deleted in a single execution. Additional tags must be deleted in another execution. We recommend starting with a low number, like 100, and increasing it after monitoring that container images are properly deleted.

For self-managed instances, those settings can be updated in the Rails console:

  ApplicationSetting.last.update(container_registry_expiration_policies_worker_capacity: 3)

Alternatively, once the limits are enabled, they are available in the administrator area:

  1. On the top bar, select Menu > Admin.
  2. Go to Settings > CI/CD > Container Registry.

Enable or disable cleanup policy limits

The cleanup policies limits are under development and not ready for production use. They are deployed behind a feature flag that is disabled by default. GitLab administrators with access to the GitLab Rails console can enable it.

To enable it:

Feature.enable(:container_registry_expiration_policies_throttling)

To disable it:

Feature.disable(:container_registry_expiration_policies_throttling)

Use the cleanup policy API

You can set, update, and disable the cleanup policies using the GitLab API.

Examples:

  • Select all tags, keep at least 1 tag per image, clean up any tag older than 14 days, run once a month, preserve any images with the name main and the policy is enabled:

    curl --request PUT --header 'Content-Type: application/json;charset=UTF-8' --header "PRIVATE-TOKEN: <your_access_token>" \
         --data-binary '{"container_expiration_policy_attributes":{"cadence":"1month","enabled":true,"keep_n":1,"older_than":"14d","name_regex":"","name_regex_delete":".*","name_regex_keep":".*-main"}}' \
         "https://gitlab.example.com/api/v4/projects/2"
    

Valid values for cadence when using the API are:

  • 1d (every day)
  • 7d (every week)
  • 14d (every two weeks)
  • 1month (every month)
  • 3month (every quarter)

See the API documentation for further details: Edit project.

Use with external container registries

When using an external container registry, running a cleanup policy on a project may have some performance risks. If a project runs a policy to remove thousands of tags the GitLab background jobs may get backed up or fail completely. It is recommended you only enable container cleanup policies for projects that were created before GitLab 12.8 if you are confident the number of tags being cleaned up is minimal.

Troubleshooting cleanup policies

If you see the following message:

“Something went wrong while updating the cleanup policy.”

Check the regex patterns to ensure they are valid.

GitLab uses RE2 syntax for regular expressions in the cleanup policy. You can test them with the regex101 regex tester. View some common regex pattern examples.