1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
#! /usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2015 Neil Williams <codehelp@debian.org>
#
# 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/>.
import os
import sys
import cliapp
import guestfs
import tarfile
import logging
__version__ = '0.1'
__desc__ = "Helper to mount an image read-only and extract files" + \
" or directories."
# pylint: disable=missing-docstring
class VmExtract(cliapp.Application): # pylint: disable=too-many-public-methods
"""
Support for extracting useful content from VM images.
For example, to assist in validation.
"""
def __init__(
self, progname=None,
version=__version__, description=__desc__, epilog=None):
super(VmExtract, self).__init__(
progname, version,
description, epilog)
self.guest_os = None
self.mps = []
def add_settings(self):
self.settings.boolean(
['verbose'], 'report what is going on')
self.settings.string(
['image'], 'image to read', metavar='FILE')
self.settings.string(
['directory'], 'directory to extract as a tarball.')
self.settings.string_list(
['path'], 'path to the filename to extract - can repeat.')
self.settings.boolean(
['boot'], 'mount the boot partition as well as root')
self.settings.string(
['filename'],
'name of tarball containing the extracted directory',
default='vmextract.tgz',
metavar='FILE')
# pylint: disable=too-many-branches,too-many-statements
def process_args(self, args):
if not self.settings['image']:
raise cliapp.AppException(
'You must give an image to read')
if not self.settings['directory'] and not self.settings['path']:
raise cliapp.AppException(
'You must provide either a filename or directory '
'to extract')
try:
self.prepare()
self.mount_root()
if self.settings['boot']:
self.mount_boot()
if self.settings['directory']:
self.extract_directory()
elif self.settings['path']:
for path in self.settings['path']:
self.download(path)
except BaseException as exc:
self.message('EEEK! Something bad happened... %s' % exc)
sys.exit(1)
def message(self, msg):
logging.info(msg)
if self.settings['verbose']:
print(msg)
def prepare(self):
"""
Initialise guestfs
"""
self.message("Preparing %s" % self.settings['image'])
self.guest_os = guestfs.GuestFS(python_return_dict=True)
self.guest_os.add_drive_opts(
self.settings['image'],
format="raw",
readonly=1)
# ensure launch is only called once per run
self.guest_os.launch()
drives = self.guest_os.inspect_os()
self.mps = self.guest_os.inspect_get_mountpoints(drives[0])
def download(self, path):
"""
Copy a single file out of the image
If a filename is not specified, use the basename of the original.
"""
filename = os.path.basename(path)
self.message(
"Extracting %s as %s" % (path, filename))
self.guest_os.download(path, filename)
if not os.path.exists(filename):
return RuntimeError("Download failed")
def mount_root(self):
"""
Mounts the root partition to /
"""
root = [part for part in self.mps if part == '/'][0]
if not root:
raise RuntimeError("Unable to identify root partition")
self.guest_os.mount_ro(self.mps[root], '/')
def mount_boot(self):
"""
Mounts the /boot partition to a new /boot mountpoint
"""
boot = [part for part in self.mps if part == '/boot'][0]
if not boot:
raise RuntimeError("Unable to identify boot partition")
if not self.guest_os.is_dir('/boot'):
self.guest_os.mkmountpoint('/boot')
self.guest_os.mount_ro(self.mps[boot], '/boot')
def extract_directory(self):
"""
Create a tarball of a complete directory existing in the image.
"""
if not self.settings['filename']:
self.settings['filename'] = 'vmextract.tgz'
self.guest_os.tar_out(
self.settings['directory'],
self.settings['filename'], compress='gzip')
if not tarfile.is_tarfile(self.settings['filename']):
raise RuntimeError("Extraction failed")
def main():
VmExtract(version=__version__).run()
return 0
if __name__ == '__main__':
main()
|
