docker-image-extract.py

#!/usr/bin/python3
#
# 1. $ docker save -o foo.tar image
#
# 2. Call me like this:
#  docker-image-extract tarfile.tar extracted
# to install $ sudo curl -Lo /usr/local/bin/docker-image-extract  https://gist.githubusercontent.com/smijar/0f4a5a8a8ce69ed54baa6e82063ff074/raw/e4f50bc636a27d88aa1a3fbf3073ceff271bbf4b/docker-image-extract.py

import tarfile
import json
import os
import sys

image_path = sys.argv[1]
extracted_path = sys.argv[2]

image = tarfile.open(image_path)
manifest = json.loads(image.extractfile('manifest.json').read())

for layer in manifest[0]['Layers']:
    print('Found layer: %s' % layer)
    layer_tar = tarfile.open(fileobj=image.extractfile(layer))

    for tarinfo in layer_tar:
        print('  ... %s' % tarinfo.name)
        if tarinfo.isdev():
            print('  --> skip device files')
            continue

        dest = os.path.join(extracted_path, tarinfo.name)
        if not tarinfo.isdir() and os.path.exists(dest):
            print('  --> remove old version of file')
            os.unlink(dest)

        layer_tar.extract(tarinfo, path=extracted_path)