---
features:
  - |
    Adds support for configuring the Docker Registry by providing environment
    variables to its container via the ``docker_registry_env`` Ansible
    variable. For example, the registry can be configured as a pull through
    cache to Docker Hub using:

    .. code-block:: text

      docker_registry_env:
        REGISTRY_PROXY_REMOTEURL: "https://registry-1.docker.io"

    Note that it is not possible to push to a registry configured as a
    pull through cache. See `story 2004817
    <https://storyboard.openstack.org/#!/story/2004817>`__ for details and the
    `Docker documentation <https://docs.docker.com/registry/configuration/>`__
    for the full list of configuration options.