Searches and removes dangling docker volumes

docker-volumes.py

#!/usr/bin/env python
"""
Largely based on https://github.com/docker/docker/issues/6354#issuecomment-60817733
All credit goes to https://github.com/adamhadani
"""
import logging
import os
import os.path
import sys
import argparse

from shutil import rmtree
import docker




def get_immediate_subdirectories(a_dir):
    return [os.path.join(a_dir, name) for name in os.listdir(a_dir)
            if os.path.isdir(os.path.join(a_dir, name))]


def main():
    parser = argparse.ArgumentParser(description='Identify and remove dangling Docker volumes.')
    parser.add_argument('-k', '--clean', dest='clean', action='store_true')
    options = parser.parse_args()

    logging.basicConfig(level=logging.INFO, format="%(message)s")

    client = docker.Client()
    DOCKER_VOLUMES_DIR = os.path.join(client.info()['DockerRootDir'], 'volumes')

    valid_dirs = []
    for container in client.containers(all=True):
        volumes = client.inspect_container(container['Id'])['Volumes']
        if not volumes:
            continue

        for _, real_path in volumes.iteritems():
            if real_path.startswith(DOCKER_VOLUMES_DIR):
                valid_dirs.append(real_path)

    all_dirs = get_immediate_subdirectories(DOCKER_VOLUMES_DIR)
    invalid_dirs = set(all_dirs).difference(valid_dirs)

    logging.info("%s dangling Docker volumes out of %s total volumes found.", len(invalid_dirs), len(all_dirs))
    for invalid_dir in invalid_dirs:
        if options.clean:
            logging.info("Purging directory: %s", invalid_dir)
            rmtree(invalid_dir)
        else:
            logging.info("Dangling volume: %s", invalid_dir)

    logging.info("All done.")


if __name__ == "__main__":
    sys.exit(main())