Awesome

Unpacks a Docker image.

Usage

usage: undocker.py [-h] [--ignore-errors] [--output OUTPUT] [--verbose]
                   [--debug] [--list] [--layer LAYER]
                   image

positional arguments:
  image

optional arguments:
  -h, --help            show this help message and exit
  --ignore-errors, -i   Ignore OS errors when extracting files
  --output OUTPUT, -o OUTPUT
                        Output directory (defaults to ".")
  --verbose, -v
  --debug, -d
  --list, --ls          List layers in an image
  --layer LAYER, -l LAYER
                        Extract only the specified layer

Examples

Extract an entire image:

$ docker save busybox | undocker -i -o busybox busybox

The -i option is necessary here because I am not running as root, and the extract operation will fail when it attempts to create device nodes.

List the layers in an image:

$ docker save busybox | undocker --list
511136ea3c5a64f264b78b5433614aec563103b4d4702f3ba7d4d2698e22c158
df7546f9f060a2268024c8a230d8639878585defcc1bc6f79d2728a13957871b
ea13149945cb6b1e746bf28032f02e9b5a793523481a0a18645fc77ad53c4ea2
4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125

Extract only specific layers:

$ docker save busybox |
  undocker -o busybox -v \
  -l 4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125 \
  busybox
INFO:undocker:extracting image busybox (4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125)
INFO:undocker:extracting layer 4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125

License

undocker -- a tool for decomposing Docker images
Copyright (C) 2015 Lars Kellogg-Stedman lars@oddbit.com

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.