root / image_creator / bundle_volume.py @ e62eb365
History | View | Annotate | Download (15.9 kB)
1 |
# Copyright 2012 GRNET S.A. All rights reserved.
|
---|---|
2 |
#
|
3 |
# Redistribution and use in source and binary forms, with or
|
4 |
# without modification, are permitted provided that the following
|
5 |
# conditions are met:
|
6 |
#
|
7 |
# 1. Redistributions of source code must retain the above
|
8 |
# copyright notice, this list of conditions and the following
|
9 |
# disclaimer.
|
10 |
#
|
11 |
# 2. Redistributions in binary form must reproduce the above
|
12 |
# copyright notice, this list of conditions and the following
|
13 |
# disclaimer in the documentation and/or other materials
|
14 |
# provided with the distribution.
|
15 |
#
|
16 |
# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
|
17 |
# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
18 |
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
19 |
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
|
20 |
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
21 |
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
22 |
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
23 |
# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
24 |
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
25 |
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
26 |
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
27 |
# POSSIBILITY OF SUCH DAMAGE.
|
28 |
#
|
29 |
# The views and conclusions contained in the software and
|
30 |
# documentation are those of the authors and should not be
|
31 |
# interpreted as representing official policies, either expressed
|
32 |
# or implied, of GRNET S.A.
|
33 |
|
34 |
import os |
35 |
import re |
36 |
import tempfile |
37 |
from collections import namedtuple |
38 |
|
39 |
import parted |
40 |
|
41 |
from image_creator.rsync import Rsync |
42 |
from image_creator.util import get_command |
43 |
from image_creator.util import FatalError |
44 |
from image_creator.util import try_fail_repeat |
45 |
from image_creator.util import free_space |
46 |
|
47 |
findfs = get_command('findfs')
|
48 |
dd = get_command('dd')
|
49 |
dmsetup = get_command('dmsetup')
|
50 |
losetup = get_command('losetup')
|
51 |
mount = get_command('mount')
|
52 |
umount = get_command('umount')
|
53 |
blkid = get_command('blkid')
|
54 |
|
55 |
MKFS_OPTS = {'ext2': ['-F'], |
56 |
'ext3': ['-F'], |
57 |
'ext4': ['-F'], |
58 |
'reiserfs': ['-ff'], |
59 |
'btrfs': [],
|
60 |
'minix': [],
|
61 |
'xfs': ['-f'], |
62 |
'jfs': ['-f'], |
63 |
'ntfs': ['-F'], |
64 |
'msdos': [],
|
65 |
'vfat': []}
|
66 |
|
67 |
|
68 |
class BundleVolume(object): |
69 |
"""This class can be used to create an image out of the running system"""
|
70 |
|
71 |
def __init__(self, out, meta, tmp=None): |
72 |
"""Create an instance of the BundleVolume class."""
|
73 |
self.out = out
|
74 |
self.meta = meta
|
75 |
self.tmp = tmp
|
76 |
|
77 |
self.out.output('Searching for root device ...', False) |
78 |
root = self._get_root_partition()
|
79 |
|
80 |
if root.startswith("UUID=") or root.startswith("LABEL="): |
81 |
root = findfs(root).stdout.strip() |
82 |
|
83 |
if not re.match('/dev/[hsv]d[a-z][1-9]*$', root): |
84 |
raise FatalError("Don't know how to handle root device: %s" % root) |
85 |
|
86 |
out.success(root) |
87 |
|
88 |
disk_file = re.split('[0-9]', root)[0] |
89 |
device = parted.Device(disk_file) |
90 |
self.disk = parted.Disk(device)
|
91 |
|
92 |
def _read_fstable(self, f): |
93 |
|
94 |
if not os.path.isfile(f): |
95 |
raise FatalError("Unable to open: `%s'. File is missing." % f) |
96 |
|
97 |
FileSystemTableEntry = namedtuple('FileSystemTableEntry',
|
98 |
'dev mpoint fs opts freq passno')
|
99 |
with open(f) as table: |
100 |
for line in iter(table): |
101 |
entry = line.split('#')[0].strip().split() |
102 |
if len(entry) != 6: |
103 |
continue
|
104 |
yield FileSystemTableEntry(*entry)
|
105 |
|
106 |
def _get_root_partition(self): |
107 |
for entry in self._read_fstable('/etc/fstab'): |
108 |
if entry.mpoint == '/': |
109 |
return entry.dev
|
110 |
|
111 |
raise FatalError("Unable to find root device in /etc/fstab") |
112 |
|
113 |
def _is_mpoint(self, path): |
114 |
for entry in self._read_fstable('/proc/mounts'): |
115 |
if entry.mpoint == path:
|
116 |
return True |
117 |
return False |
118 |
|
119 |
def _get_mount_options(self, device): |
120 |
for entry in self._read_fstable('/proc/mounts'): |
121 |
if not entry.dev.startswith('/'): |
122 |
continue
|
123 |
|
124 |
if os.path.realpath(entry.dev) == os.path.realpath(device):
|
125 |
return entry
|
126 |
|
127 |
return None |
128 |
|
129 |
def _create_partition_table(self, image): |
130 |
|
131 |
if self.disk.type != 'msdos': |
132 |
raise FatalError('Only msdos partition tables are supported') |
133 |
|
134 |
# Copy the MBR and the space between the MBR and the first partition.
|
135 |
# In Grub version 1 Stage 1.5 is located there.
|
136 |
first_sector = self.disk.getPrimaryPartitions()[0].geometry.start |
137 |
|
138 |
dd('if=%s' % self.disk.device.path, 'of=%s' % image, |
139 |
'bs=%d' % self.disk.device.sectorSize, |
140 |
'count=%d' % first_sector, 'conv=notrunc') |
141 |
|
142 |
# Create the Extended boot records (EBRs) in the image
|
143 |
extended = self.disk.getExtendedPartition()
|
144 |
if not extended: |
145 |
return
|
146 |
|
147 |
# Extended boot records precede the logical partitions they describe
|
148 |
logical = self.disk.getLogicalPartitions()
|
149 |
start = extended.geometry.start |
150 |
for i in range(len(logical)): |
151 |
end = logical[i].geometry.start - 1
|
152 |
dd('if=%s' % self.disk.device.path, 'of=%s' % image, |
153 |
'count=%d' % (end - start + 1), 'conv=notrunc', |
154 |
'seek=%d' % start, 'skip=%d' % start) |
155 |
start = logical[i].geometry.end + 1
|
156 |
|
157 |
def _get_partitions(self, disk): |
158 |
Partition = namedtuple('Partition', 'num start end type fs') |
159 |
|
160 |
partitions = [] |
161 |
for p in disk.partitions: |
162 |
num = p.number |
163 |
start = p.geometry.start |
164 |
end = p.geometry.end |
165 |
ptype = p.type |
166 |
fs = p.fileSystem.type if p.fileSystem is not None else '' |
167 |
partitions.append(Partition(num, start, end, ptype, fs)) |
168 |
|
169 |
return partitions
|
170 |
|
171 |
def _shrink_partitions(self, image): |
172 |
|
173 |
new_end = self.disk.device.length
|
174 |
|
175 |
image_dev = parted.Device(image) |
176 |
image_disk = parted.Disk(image_dev) |
177 |
|
178 |
is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
|
179 |
is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
|
180 |
|
181 |
partitions = self._get_partitions(self.disk) |
182 |
|
183 |
last = partitions[-1]
|
184 |
if last.fs == 'linux-swap(v1)': |
185 |
MB = 2 ** 20 |
186 |
size = (last.end - last.start + 1) * self.disk.device.sectorSize |
187 |
self.meta['SWAP'] = "%d:%s" % (last.num, (size + MB - 1) // MB) |
188 |
|
189 |
image_disk.deletePartition( |
190 |
image_disk.getPartitionBySector(last.start)) |
191 |
image_disk.commit() |
192 |
|
193 |
if is_logical(last) and last.num == 5: |
194 |
extended = image_disk.getExtendedPartition() |
195 |
image_disk.deletePartition(extended) |
196 |
image_disk.commit() |
197 |
partitions.remove(filter(is_extended, partitions)[0]) |
198 |
|
199 |
partitions.remove(last) |
200 |
last = partitions[-1]
|
201 |
|
202 |
# Leave 2048 blocks at the end
|
203 |
new_end = last.end + 2048
|
204 |
|
205 |
mount_options = self._get_mount_options(
|
206 |
self.disk.getPartitionBySector(last.start).path)
|
207 |
if mount_options is not None: |
208 |
stat = os.statvfs(mount_options.mpoint) |
209 |
# Shrink the last partition. The new size should be the size of the
|
210 |
# occupied blocks
|
211 |
blcks = stat.f_blocks - stat.f_bavail |
212 |
new_size = (blcks * stat.f_frsize) // self.disk.device.sectorSize
|
213 |
|
214 |
# Add 10% just to be on the safe side
|
215 |
part_end = last.start + (new_size * 11) // 10 |
216 |
# Align to 2048
|
217 |
part_end = ((part_end + 2047) // 2048) * 2048 |
218 |
|
219 |
image_disk.setPartitionGeometry( |
220 |
image_disk.getPartitionBySector(last.start), |
221 |
parted.Constraint(device=image_disk.device), |
222 |
start=last.start, end=part_end) |
223 |
image_disk.commit() |
224 |
|
225 |
# Parted may have changed this for better alignment
|
226 |
part_end = image_disk.getPartitionBySector(last.start).geometry.end |
227 |
last = last._replace(end=part_end) |
228 |
partitions[-1] = last
|
229 |
|
230 |
# Leave 2048 blocks at the end.
|
231 |
new_end = part_end + 2048
|
232 |
|
233 |
if last.type == parted.PARTITION_LOGICAL:
|
234 |
# Fix the extended partition
|
235 |
extended = disk.getExtendedPartition() |
236 |
|
237 |
image_disk.setPartitionGeometry( |
238 |
extended, parted.Constraint(device=img_dev), |
239 |
ext.geometry.start, end=last.end) |
240 |
image_disk.commit() |
241 |
|
242 |
image_dev.destroy() |
243 |
return new_end
|
244 |
|
245 |
def _map_partition(self, dev, num, start, end): |
246 |
name = os.path.basename(dev) |
247 |
tablefd, table = tempfile.mkstemp() |
248 |
try:
|
249 |
size = end - start + 1
|
250 |
os.write(tablefd, "0 %d linear %s %d" % (size, dev, start))
|
251 |
dmsetup('create', "%sp%d" % (name, num), table) |
252 |
finally:
|
253 |
os.unlink(table) |
254 |
|
255 |
return "/dev/mapper/%sp%d" % (name, num) |
256 |
|
257 |
def _unmap_partition(self, dev): |
258 |
if not os.path.exists(dev): |
259 |
return
|
260 |
|
261 |
try_fail_repeat(dmsetup, 'remove', dev.split('/dev/mapper/')[1]) |
262 |
|
263 |
def _mount(self, target, devs): |
264 |
|
265 |
devs.sort(key=lambda d: d[1]) |
266 |
for dev, mpoint in devs: |
267 |
absmpoint = os.path.abspath(target + mpoint) |
268 |
if not os.path.exists(absmpoint): |
269 |
os.makedirs(absmpoint) |
270 |
mount(dev, absmpoint) |
271 |
|
272 |
def _umount_all(self, target): |
273 |
mpoints = [] |
274 |
for entry in self._read_fstable('/proc/mounts'): |
275 |
if entry.mpoint.startswith(os.path.abspath(target)):
|
276 |
mpoints.append(entry.mpoint) |
277 |
|
278 |
mpoints.sort() |
279 |
for mpoint in reversed(mpoints): |
280 |
try_fail_repeat(umount, mpoint) |
281 |
|
282 |
def _to_exclude(self): |
283 |
excluded = ['/tmp', '/var/tmp'] |
284 |
if self.tmp is not None: |
285 |
excluded.append(self.tmp)
|
286 |
local_filesystems = MKFS_OPTS.keys() + ['rootfs']
|
287 |
for entry in self._read_fstable('/proc/mounts'): |
288 |
if entry.fs in local_filesystems: |
289 |
continue
|
290 |
|
291 |
mpoint = entry.mpoint |
292 |
if mpoint in excluded: |
293 |
continue
|
294 |
|
295 |
descendants = filter(
|
296 |
lambda p: p.startswith(mpoint + '/'), excluded) |
297 |
if len(descendants): |
298 |
for d in descendants: |
299 |
excluded.remove(d) |
300 |
excluded.append(mpoint) |
301 |
continue
|
302 |
|
303 |
dirname = mpoint |
304 |
basename = ''
|
305 |
found_ancestor = False
|
306 |
while dirname != '/': |
307 |
(dirname, basename) = os.path.split(dirname) |
308 |
if dirname in excluded: |
309 |
found_ancestor = True
|
310 |
break
|
311 |
|
312 |
if not found_ancestor: |
313 |
excluded.append(mpoint) |
314 |
|
315 |
return excluded
|
316 |
|
317 |
def _replace_uuids(self, target, new_uuid): |
318 |
|
319 |
files = ['/etc/fstab',
|
320 |
'/boot/grub/grub.cfg',
|
321 |
'/boot/grub/menu.lst',
|
322 |
'/boot/grub/grub.conf']
|
323 |
|
324 |
orig = dict(map( |
325 |
lambda p: (
|
326 |
p.number, |
327 |
blkid('-s', 'UUID', '-o', 'value', p.path).stdout.strip()), |
328 |
self.disk.partitions))
|
329 |
|
330 |
for f in map(lambda f: target + f, files): |
331 |
|
332 |
if not os.path.exists(f): |
333 |
continue
|
334 |
|
335 |
with open(f, 'r') as src: |
336 |
lines = src.readlines() |
337 |
with open(f, 'w') as dest: |
338 |
for line in lines: |
339 |
for i, uuid in new_uuid.items(): |
340 |
line = re.sub(orig[i], uuid, line) |
341 |
dest.write(line) |
342 |
|
343 |
def _create_filesystems(self, image): |
344 |
|
345 |
filesystem = {} |
346 |
for p in self.disk.partitions: |
347 |
filesystem[p.number] = self._get_mount_options(p.path)
|
348 |
|
349 |
partitions = self._get_partitions(parted.Disk(parted.Device(image)))
|
350 |
unmounted = filter(lambda p: filesystem[p.num] is None, partitions) |
351 |
mounted = filter(lambda p: filesystem[p.num] is not None, partitions) |
352 |
|
353 |
# For partitions that are not mounted right now, we can simply dd them
|
354 |
# into the image.
|
355 |
for p in unmounted: |
356 |
dd('if=%s' % self.disk.device.path, 'of=%s' % image, |
357 |
'count=%d' % (p.end - p.start + 1), 'conv=notrunc', |
358 |
'seek=%d' % p.start, 'skip=%d' % p.start) |
359 |
|
360 |
loop = str(losetup('-f', '--show', image)).strip() |
361 |
mapped = {} |
362 |
try:
|
363 |
for p in mounted: |
364 |
i = p.num |
365 |
mapped[i] = self._map_partition(loop, i, p.start, p.end)
|
366 |
|
367 |
new_uuid = {} |
368 |
# Create the file systems
|
369 |
for i, dev in mapped.iteritems(): |
370 |
fs = filesystem[i].fs |
371 |
self.out.output('Creating %s filesystem on partition %d ... ' % |
372 |
(fs, i), False)
|
373 |
get_command('mkfs.%s' % fs)(*(MKFS_OPTS[fs] + [dev]))
|
374 |
self.out.success('done') |
375 |
new_uuid[i] = blkid( |
376 |
'-s', 'UUID', '-o', 'value', dev).stdout.strip() |
377 |
|
378 |
target = tempfile.mkdtemp() |
379 |
try:
|
380 |
absmpoints = self._mount(target,
|
381 |
[(mapped[i], filesystem[i].mpoint) |
382 |
for i in mapped.keys()]) |
383 |
excluded = self._to_exclude()
|
384 |
|
385 |
rsync = Rsync(self.out)
|
386 |
|
387 |
# Excluded paths need to be relative to the source
|
388 |
for excl in map(lambda p: os.path.relpath(p, '/'), |
389 |
excluded + [image]): |
390 |
rsync.exclude(excl) |
391 |
|
392 |
rsync.archive().hard_links().xattrs().sparse().acls() |
393 |
rsync.run('/', target, 'host', 'temporary image') |
394 |
|
395 |
# Create missing mountpoints. Since they are mountpoints, we
|
396 |
# cannot determine the ownership and the mode of the real
|
397 |
# directory. Make them inherit those properties from their
|
398 |
# parent dir
|
399 |
for excl in excluded: |
400 |
dirname = os.path.dirname(excl) |
401 |
stat = os.stat(dirname) |
402 |
os.mkdir(target + excl, stat.st_mode) |
403 |
os.chown(target + excl, stat.st_uid, stat.st_gid) |
404 |
|
405 |
# We need to replace the old UUID referencies with the new
|
406 |
# ones in grub configuration files and /etc/fstab for file
|
407 |
# systems that have been recreated.
|
408 |
self._replace_uuids(target, new_uuid)
|
409 |
|
410 |
finally:
|
411 |
self._umount_all(target)
|
412 |
os.rmdir(target) |
413 |
finally:
|
414 |
for dev in mapped.values(): |
415 |
self._unmap_partition(dev)
|
416 |
losetup('-d', loop)
|
417 |
|
418 |
def create_image(self, image): |
419 |
"""Given an image filename, this method will create an image out of the
|
420 |
running system.
|
421 |
"""
|
422 |
|
423 |
size = self.disk.device.length * self.disk.device.sectorSize |
424 |
|
425 |
# Create sparse file to host the image
|
426 |
fd = os.open(image, os.O_WRONLY | os.O_CREAT) |
427 |
try:
|
428 |
os.ftruncate(fd, size) |
429 |
finally:
|
430 |
os.close(fd) |
431 |
|
432 |
self._create_partition_table(image)
|
433 |
|
434 |
end_sector = self._shrink_partitions(image)
|
435 |
|
436 |
size = (end_sector + 1) * self.disk.device.sectorSize |
437 |
|
438 |
# Truncate image to the new size.
|
439 |
fd = os.open(image, os.O_RDWR) |
440 |
try:
|
441 |
os.ftruncate(fd, size) |
442 |
finally:
|
443 |
os.close(fd) |
444 |
|
445 |
# Check if the available space is enough to host the image
|
446 |
dirname = os.path.dirname(image) |
447 |
self.out.output("Examining available space ...", False) |
448 |
if free_space(dirname) <= size:
|
449 |
raise FatalError('Not enough space under %s to host the image' % |
450 |
dirname) |
451 |
self.out.success("sufficient") |
452 |
|
453 |
self._create_filesystems(image)
|
454 |
|
455 |
return image
|
456 |
|
457 |
# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :
|