curl https://raw.githubusercontent.com/burnettk/delete-docker-registry-image/master/delete_docker_registry_image.py | sudo tee /usr/local/bin/delete_docker_registry_image >/dev/null
sudo chmod a+x /usr/local/bin/delete_docker_registry_image

Set up your data directory via an environment variable:

export REGISTRY_DATA_DIR=/opt/registry_data/docker/registry/v2

You can also just edit the script where this variable is set to make it work for your setup.

Almost delete a repo:

delete_docker_registry_image --image testrepo/awesomeimage --dry-run

Actually delete a repo (remember to shut down your registry first):

delete_docker_registry_image --image testrepo/awesomeimage

Delete one tag from a repo:

delete_docker_registry_image --image testrepo/awesomeimage:supertag

This complimentary script is made to remove tags in repository based on regexp pattern.

Usage:

./clean_old_versions.py --image reg_exp_of_repository_to_find --include reg_exp_of_tag_to_find -l history_to_maintain

Example:

./clean_old_versions.py --image '^repo/sitor*' --include '^0.1.*' -l 2

./test/start_up_vagrant_box_for_running_tests
vagrant ssh
cd /vagrant
./test/clean_and_run

Known test-passing configurations:

1. docker: 1.9.1, registry:2.2.1
2. docker: 1.10.2, registry:2.3.0
3. docker: 1.11.2, registry:2.3.0
4. docker: 1.12.1, registry:2.5.0

Known test-failing configurations:

1. docker: 1.10.2, registry:2.2.1

When tests are run with a new docker daemon and an older registry, architecture-specific config files are created, but they are not referenced anywhere, so tests fail when we delete a tag or repo and expect all files to be deleted, but these architecture-specific config files are still hanging around. With the newer registry, these config files are referenced in the schema version 2 manifest, so we can easily delete them. It's probably best to avoid use of this script with the version combinations that fail tests.

Docker is building or has built much of this functionality in newer versions of docker and the registry.

The ability to delete the metadata for a manifest was added in registry:2.2. Make sure you give the registry the environment variable REGISTRY_STORAGE_DELETE_ENABLED=true. Follow the instructions at docker-archive/docker-registry#988 (comment) to delete a tag by name. Once the metadata is deleted, follow the instructions at https://github.com/docker/distribution/blob/master/docs/configuration.md to run garbage collection, which will clean up the binary data (the big stuff).