Purge old docer images from registry

purge_docker_images.py

import argparse
import logging
import re
import subprocess
import sys

try:
    import pydor
except ImportError:
    print('Plese run:')
    print('sudo pip install git+https://github.com/dohnto/pydor')
    sys.exit(-1)

TAG_PATTERN = re.compile(r'(?P<major>\d+)\.(?P<minor>\d+)(\.(?P<patch>\d+))?(-(dev|test)(?P<dev>\d+))?')


def confirm():
    while True:
        res = input('Is it OK? (y/n)')
        if res == 'y':
            return True
        elif res == 'n':
            return False


def purge(registry_host, repository_prefix, keep_images=10, use_local_skopeo=False):
    api = pydor.API(registry_host, insecure=True)
    for repository in api.Catalog():
        if not repository.startswith(repository_prefix):
            continue

        images = {}
        for tag in api.Tags(repository):
            match = TAG_PATTERN.match(tag)
            if not match:
                logging.warning('Tag %s of repository %s does not have semantic versioning', tag, repository)
                continue
            tag_parts = match.groupdict()
            tag_parts = {name: int(value) if value else 0 for name, value in tag_parts.items()}

            image = '{}/{}:{}'.format(registry_host, repository, tag)
            images[(tag_parts['major'], tag_parts['minor'], tag_parts['patch'], tag_parts['dev'])] = image

        image_keys = sorted(images.keys())
        images_to_delete = image_keys[:-keep_images]
        images_to_keep = image_keys[-keep_images:]

        print('\033[93m', 'These images will be preserved:', '\033[0m')
        print('\n'.join([images[image] for image in images_to_keep]))
        print('\033[93m', 'These images will be deleted:', '\033[0m')
        print('\n'.join([images[image] for image in images_to_delete]))

        if confirm():
            image_count = len(images_to_delete)
            for i, image in enumerate(images_to_delete):
                print(
                    'Deleting image: ',
                    '{:>5}/{}'.format(i + 1, image_count),
                    images[image],
                    '\r',
                    end='',
                    flush=True
                )
                if use_local_skopeo:
                    subprocess.check_call([
                        'skopeo',
                        'delete',
                        '--tls-verify=false',
                        'docker://{}'.format(images[image])
                    ])
                else:
                    subprocess.check_call([
                        'docker', 'run', 'doc.ker.dev.dszn.cz/tomas.dohnalek:skopeo',
                        '/go/src/github.com/containers/skopeo/skopeo',
                        'delete',
                        '--tls-verify=false',
                        'docker://{}'.format(images[image])
                    ])


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--keep', default=10, nargs='?', type=int)
    parser.add_argument('--registry', default='doc.ker.dev.dszn.cz', nargs='?')
    parser.add_argument('--use-local-skopeo', action='store_true')
    parser.add_argument('repository', help='prefix of the repository name')
    args = parser.parse_args()

    purge(args.registry, args.repository, args.keep, args.use_local_skopeo)