1 # Copyright 2012 GRNET S.A. All rights reserved.
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4 # without modification, are permitted provided that the following
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8 # copyright notice, this list of conditions and the following
11 # 2. Redistributions in binary form must reproduce the above
12 # copyright notice, this list of conditions and the following
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14 # provided with the distribution.
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39 from collections import namedtuple
43 from image_creator.rsync import Rsync
44 from image_creator.util import get_command
45 from image_creator.util import FatalError
47 findfs = get_command('findfs')
48 truncate = get_command('truncate')
49 dd = get_command('dd')
50 dmsetup = get_command('dmsetup')
51 losetup = get_command('losetup')
52 mount = get_command('mount')
53 umount = get_command('umount')
54 blkid = get_command('blkid')
73 def __init__(self, out, meta):
77 self.out.output('Searching for root device ...', False)
78 root = self._get_root_partition()
80 if root.startswith("UUID=") or root.startswith("LABEL="):
81 root = findfs(root).stdout.strip()
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)
88 disk_file = re.split('[0-9]', root)[0]
89 device = parted.Device(disk_file)
90 self.disk = parted.Disk(device)
92 def _read_fstable(self, f):
94 if not os.path.isfile(f):
95 raise FatalError("Unable to open: `%s'. File is missing." % f)
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()
104 yield FileSystemTableEntry(*entry)
106 def _get_root_partition(self):
107 for entry in self._read_fstable('/etc/fstab'):
108 if entry.mpoint == '/':
111 raise FatalError("Unable to find root device in /etc/fstab")
113 def _is_mpoint(self, path):
114 for entry in self._read_fstable('/proc/mounts'):
115 if entry.mpoint == path:
119 def _get_mount_options(self, device):
120 for entry in self._read_fstable('/proc/mounts'):
121 if not entry.dev.startswith('/'):
124 if os.path.realpath(entry.dev) == os.path.realpath(device):
129 def _create_partition_table(self, image):
131 if self.disk.type != 'msdos':
132 raise FatalError('Only msdos partition tables are supported')
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
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')
142 # Create the Extended boot records (EBRs) in the image
143 extended = self.disk.getExtendedPartition()
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
157 def _get_partitions(self, disk):
158 Partition = namedtuple('Partition', 'num start end type fs')
161 for p in disk.partitions:
163 start = p.geometry.start
166 fs = p.fileSystem.type if p.fileSystem is not None else ''
167 partitions.append(Partition(num, start, end, ptype, fs))
171 def _shrink_partitions(self, image):
173 new_end = self.disk.device.getLength()
175 image_dev = parted.Device(image)
176 image_disk = parted.Disk(image_dev)
178 is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
179 is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
181 partitions = self._get_partitions(self.disk)
183 last = partitions[-1]
184 if last.fs == 'linux-swap(v1)':
186 size = (last.end - last.start + 1) * self.disk.device.sectorSize
187 self.meta['SWAP'] = "%d:%s" % (last.num, (size + MB - 1) // MB)
189 image_disk.deletePartition(
190 image_disk.getPartitionBySector(last.start))
193 if is_logical(last) and last.num == 5:
194 extended = image_disk.getExtendedPartition()
195 image_disk.deletePartition(extended)
197 partitions.remove(filter(is_extended, partitions)[0])
199 partitions.remove(last)
200 last = partitions[-1]
202 # Leave 2048 blocks at the end
203 new_end = last.end + 2048
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
211 blcks = stat.f_blocks - stat.f_bavail
212 new_size = (blcks * stat.f_frsize) // self.disk.device.sectorSize
214 # Add 10% just to be on the safe side
215 part_end = last.start + (new_size * 11) // 10
217 part_end = ((part_end + 2047) // 2048) * 2048
219 image_disk.setPartitionGeometry(
220 image_disk.getPartitionBySector(last.start),
221 parted.Constraint(device=image_disk.device),
222 start=last.start, end=part_end)
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
230 # Leave 2048 blocks at the end.
231 new_end = part_end + 2048
233 if last.type == parted.PARTITION_LOGICAL:
234 # Fix the extended partition
235 extended = disk.getExtendedPartition()
237 image_disk.setPartitionGeometry(extended,
238 parted.Constraint(device=img_dev),
239 ext.geometry.start, end=last.end)
245 def _map_partition(self, dev, num, start, end):
246 name = os.path.basename(dev)
247 tablefd, table = tempfile.mkstemp()
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)
255 return "/dev/mapper/%sp%d" % (name, num)
257 def _unmap_partition(self, dev):
258 if not os.path.exists(dev):
261 dmsetup('remove', dev.split('/dev/mapper/')[1])
264 def _mount(self, target, devs):
266 devs.sort(key=lambda d: d[1])
267 for dev, mpoint in devs:
268 absmpoint = os.path.abspath(target + mpoint)
269 if not os.path.exists(absmpoint):
270 os.makedirs(absmpoint)
271 mount(dev, absmpoint)
273 def _umount_all(self, target):
275 for entry in self._read_fstable('/proc/mounts'):
276 if entry.mpoint.startswith(os.path.abspath(target)):
277 mpoints.append(entry.mpoint)
280 for mpoint in reversed(mpoints):
283 def _to_exclude(self):
284 excluded = ['/tmp', '/var/tmp']
285 local_filesystems = MKFS_OPTS.keys() + ['rootfs']
286 for entry in self._read_fstable('/proc/mounts'):
287 if entry.fs in local_filesystems:
290 mpoint = entry.mpoint
291 if mpoint in excluded:
294 descendants = filter(lambda p: p.startswith(mpoint + '/'),
297 for d in descendants:
299 excluded.append(mpoint)
304 found_ancestor = False
305 while dirname != '/':
306 (dirname, basename) = os.path.split(dirname)
307 if dirname in excluded:
308 found_ancestor = True
311 if not found_ancestor:
312 excluded.append(mpoint)
314 return map(lambda d: d + "/*", excluded)
316 def _replace_uuids(self, target, new_uuid):
318 files = ['/etc/fstab',
319 '/boot/grub/grub.cfg',
320 '/boot/grub/menu.lst',
321 '/boot/grub/grub.conf']
323 orig = dict(map(lambda p: (p.number, blkid( '-s', 'UUID', '-o',
324 'value', p.path).stdout.strip()), self.disk.partitions))
326 for f in map(lambda f: target + f, files):
328 if not os.path.exists(f):
331 with open(f, 'r') as src:
332 lines = src.readlines()
333 with open(f, 'w') as dest:
335 for i, uuid in new_uuid.items():
336 line = re.sub(orig[i], uuid, line)
339 def _create_filesystems(self, image):
342 for p in self.disk.partitions:
343 filesystem[p.number] = self._get_mount_options(p.path)
345 partitions = self._get_partitions(parted.Disk(parted.Device(image)))
346 unmounted = filter(lambda p: filesystem[p.num] is None, partitions)
347 mounted = filter(lambda p: filesystem[p.num] is not None, partitions)
349 # For partitions that are not mounted right now, we can simply dd them
352 dd('if=%s' % self.disk.device.path, 'of=%s' % image,
353 'count=%d' % (p.end - p.start + 1), 'conv=notrunc',
354 'seek=%d' % p.start, 'skip=%d' % p.start)
356 loop = str(losetup('-f', '--show', image)).strip()
361 mapped[i] = self._map_partition(loop, i, p.start, p.end)
364 # Create the file systems
365 for i, dev in mapped.iteritems():
366 fs = filesystem[i].fs
367 self.out.output('Creating %s filesystem on partition %d ... ' %
369 get_command('mkfs.%s' % fs)(*(MKFS_OPTS[fs] + [dev]))
370 self.out.success('done')
371 new_uuid[i] = blkid('-s', 'UUID', '-o', 'value', dev
374 target = tempfile.mkdtemp()
376 absmpoints = self._mount(target,
377 [(mapped[i], filesystem[i].mpoint) for i in mapped.keys()]
379 exclude = self._to_exclude() + [image]
380 rsync = Rsync('/', target,
381 map(lambda p: os.path.relpath(p, '/'), exclude))
382 msg = "Copying host files into the image"
383 rsync.archive().run(self.out, msg)
385 self._replace_uuids(target, new_uuid)
388 self._umount_all(target)
391 for dev in mapped.values():
392 self._unmap_partition(dev)
395 def create_image(self):
397 image = '/mnt/%s.diskdump' % uuid.uuid4().hex
399 disk_size = self.disk.device.getLength() * self.disk.device.sectorSize
401 # Create sparse file to host the image
402 truncate("-s", "%d" % disk_size, image)
404 self._create_partition_table(image)
406 end_sector = self._shrink_partitions(image)
408 # Check if the available space is enough to host the image
409 dirname = os.path.dirname(image)
410 size = (end_sector + 1) * self.disk.device.sectorSize
411 self.out.output("Examining available space in %s ..." % dirname, False)
412 stat = os.statvfs(dirname)
413 available = stat.f_bavail * stat.f_frsize
414 if available <= size:
415 raise FatalError('Not enough space in %s to host the image' %
417 self.out.success("sufficient")
419 self._create_filesystems(image)
421 # Truncate image to the new size. I counldn't find a better way to do
422 # this. It seems that python's high level functions work in a different
424 fd = os.open(image, os.O_RDWR)
426 os.ftruncate(fd, size)
432 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :