import os
import re
-import uuid
import tempfile
+import uuid
from collections import namedtuple
import parted
+from image_creator.rsync import Rsync
from image_creator.util import get_command
from image_creator.util import FatalError
+from image_creator.util import try_fail_repeat
+from image_creator.util import free_space
+from image_creator.gpt import GPTPartitionTable
findfs = get_command('findfs')
-truncate = get_command('truncate')
dd = get_command('dd')
dmsetup = get_command('dmsetup')
-
-
-class BundleVolume():
- _FileSystemEntry = namedtuple('FileSystemEntry',
- 'dev mpoint fs opts freq passno')
-
- _Partition = namedtuple('Partition', 'num start end type fs mopts')
-
- def __init__(self, out, meta):
+losetup = get_command('losetup')
+mount = get_command('mount')
+umount = get_command('umount')
+blkid = get_command('blkid')
+
+MKFS_OPTS = {'ext2': ['-F'],
+ 'ext3': ['-F'],
+ 'ext4': ['-F'],
+ 'reiserfs': ['-ff'],
+ 'btrfs': [],
+ 'minix': [],
+ 'xfs': ['-f'],
+ 'jfs': ['-f'],
+ 'ntfs': ['-F'],
+ 'msdos': [],
+ 'vfat': []}
+
+
+class BundleVolume(object):
+ """This class can be used to create an image out of the running system"""
+
+ def __init__(self, out, meta, tmp=None):
+ """Create an instance of the BundleVolume class."""
self.out = out
self.meta = meta
+ self.tmp = tmp
- self.out.output('Searching for root device...', False)
+ self.out.output('Searching for root device ...', False)
root = self._get_root_partition()
if root.startswith("UUID=") or root.startswith("LABEL="):
- self.root = findfs(root).stdout.strip()
- else:
- self.root = root
+ root = findfs(root).stdout.strip()
+
+ if not re.match('/dev/[hsv]d[a-z][1-9]*$', root):
+ raise FatalError("Don't know how to handle root device: %s" % root)
- if not re.match('/dev/[hsv]d[a-z][1-9]*$', self.root):
- raise FatalError("Don't know how to handle root device: %s" % \
- self.root)
+ out.success(root)
- self.disk = re.split('[0-9]', self.root)[0]
+ disk_file = re.split('[0-9]', root)[0]
+ device = parted.Device(disk_file)
+ self.disk = parted.Disk(device)
- out.success('%s' % root_dev)
+ def _read_fstable(self, f):
+ """Use this generator to iterate over the lines of and fstab file"""
- def _read_fstable(f):
if not os.path.isfile(f):
raise FatalError("Unable to open: `%s'. File is missing." % f)
+ FileSystemTableEntry = namedtuple('FileSystemTableEntry',
+ 'dev mpoint fs opts freq passno')
with open(f) as table:
for line in iter(table):
entry = line.split('#')[0].strip().split()
if len(entry) != 6:
continue
- yield FileSystemEntry(*entry)
+ yield FileSystemTableEntry(*entry)
- def _get_root_partition():
+ def _get_root_partition(self):
+ """Return the fstab entry accosiated with the root filesystem"""
for entry in self._read_fstable('/etc/fstab'):
if entry.mpoint == '/':
return entry.dev
raise FatalError("Unable to find root device in /etc/fstab")
- def _is_mpoint(path):
- for entry in fstable('/proc/mounts'):
+ def _is_mpoint(self, path):
+ """Check if a directory is currently a mount point"""
+ for entry in self._read_fstable('/proc/mounts'):
if entry.mpoint == path:
return True
return False
- def _mount_options(device):
- for entry in fstable('/proc/mounts'):
+ def _get_mount_options(self, device):
+ """Return the mount entry associated with a mounted device"""
+ for entry in self._read_fstable('/proc/mounts'):
if not entry.dev.startswith('/'):
continue
if os.path.realpath(entry.dev) == os.path.realpath(device):
return entry
- return
-
- def _create_partition_table(src_disk, dest_file):
+ return None
- if src_disk.type != 'msdos':
- raise FatalError('Only msdos partition tables are supported')
-
- first_sector = src_disk.getPrimaryPartitions()[0].geometry.start
+ def _create_partition_table(self, image):
+ """Copy the partition table of the host system into the image"""
# Copy the MBR and the space between the MBR and the first partition.
- # In Grub version 1 Stage 1.5 is located there.
- first_sector = src_disk.getPrimaryPartitions()[0].geometry.start
+ # In msdos partition tables Grub Stage 1.5 is located there.
+ # In gpt partition tables the Primary GPT Header is there.
+ first_sector = self.disk.getPrimaryPartitions()[0].geometry.start
- dd('if=%s' % src_disk.device.path, 'of=%s' % dest_file,
- 'bs=%d' % src_disk.device.sectorSize,
+ dd('if=%s' % self.disk.device.path, 'of=%s' % image,
+ 'bs=%d' % self.disk.device.sectorSize,
'count=%d' % first_sector, 'conv=notrunc')
+ if self.disk.type == 'gpt':
+ # Copy the Secondary GPT Header
+ table = GPTPartitionTable(self.disk.device.path)
+ dd('if=%s' % self.disk.device.path, 'of=%s' % image,
+ 'bs=%d' % self.disk.device.sectorSize, 'conv=notrunc',
+ 'seek=%d' % table.primary.last_usable_lba,
+ 'skip=%d' % table.primary.last_usable_lba)
+
# Create the Extended boot records (EBRs) in the image
- extended = src_disk.getExtendedPartition()
+ extended = self.disk.getExtendedPartition()
if not extended:
return
# Extended boot records precede the logical partitions they describe
- logical = src_disk.getLogicalPartitions()
+ logical = self.disk.getLogicalPartitions()
start = extended.geometry.start
for i in range(len(logical)):
end = logical[i].geometry.start - 1
- dd('if=%s' % src.device.path, 'of=%s' % dest,
+ dd('if=%s' % self.disk.device.path, 'of=%s' % image,
'count=%d' % (end - start + 1), 'conv=notrunc',
'seek=%d' % start, 'skip=%d' % start)
start = logical[i].geometry.end + 1
- def _shrink_partitions(src_disk, image_file):
+ def _get_partitions(self, disk):
+ """Returns a list with the partitions of the provided disk"""
+ Partition = namedtuple('Partition', 'num start end type fs')
partitions = []
- new_end = 0
+ for p in disk.partitions:
+ num = p.number
+ start = p.geometry.start
+ end = p.geometry.end
+ ptype = p.type
+ fs = p.fileSystem.type if p.fileSystem is not None else ''
+ partitions.append(Partition(num, start, end, ptype, fs))
- image_dev = parted.Device(image_file)
+ return partitions
+
+ def _shrink_partitions(self, image):
+ """Remove the last partition of the image if it is a swap partition and
+ shrink the partition before that. Make sure it can still host all the
+ files the corresponding host file system hosts
+ """
+ new_end = self.disk.device.length
+
+ image_disk = parted.Disk(parted.Device(image))
+
+ is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
+ is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
+
+ partitions = self._get_partitions(self.disk)
+
+ last = partitions[-1]
+ if last.fs == 'linux-swap(v1)':
+ MB = 2 ** 20
+ size = (last.end - last.start + 1) * self.disk.device.sectorSize
+ self.meta['SWAP'] = "%d:%s" % (last.num, (size + MB - 1) // MB)
+
+ image_disk.deletePartition(
+ image_disk.getPartitionBySector(last.start))
+ image_disk.commitToDevice()
+
+ if is_logical(last) and last.num == 5:
+ extended = image_disk.getExtendedPartition()
+ image_disk.deletePartition(extended)
+ image_disk.commitToDevice()
+ partitions.remove(filter(is_extended, partitions)[0])
+
+ partitions.remove(last)
+ last = partitions[-1]
+
+ new_end = last.end
+
+ mount_options = self._get_mount_options(
+ self.disk.getPartitionBySector(last.start).path)
+ if mount_options is not None:
+ stat = os.statvfs(mount_options.mpoint)
+ # Shrink the last partition. The new size should be the size of the
+ # occupied blocks
+ blcks = stat.f_blocks - stat.f_bavail
+ new_size = (blcks * stat.f_frsize) // self.disk.device.sectorSize
+
+ # Add 10% just to be on the safe side
+ part_end = last.start + (new_size * 11) // 10
+ # Align to 2048
+ part_end = ((part_end + 2047) // 2048) * 2048
+
+ # Make sure the partition starts where the old partition started.
+ constraint = parted.Constraint(device=image_disk.device)
+ constraint.startRange = parted.Geometry(device=image_disk.device,
+ start=last.start, length=1)
+
+ image_disk.setPartitionGeometry(
+ image_disk.getPartitionBySector(last.start), constraint,
+ start=last.start, end=part_end)
+ image_disk.commitToDevice()
+
+ # Parted may have changed this for better alignment
+ part_end = image_disk.getPartitionBySector(last.start).geometry.end
+ last = last._replace(end=part_end)
+ partitions[-1] = last
+
+ new_end = part_end
+
+ if last.type == parted.PARTITION_LOGICAL:
+ # Fix the extended partition
+ image_disk.minimizeExtendedPartition()
+
+ return (new_end, self._get_partitions(image_disk))
+
+ def _map_partition(self, dev, num, start, end):
+ """Map a partition into a block device using the device mapper"""
+ name = os.path.basename(dev) + "_" + uuid.uuid4().hex
+ tablefd, table = tempfile.mkstemp()
try:
- image_disk = parted.Disk(image_dev)
- try:
- is_extended = lambda p: p.type == parted.PARTITION_EXTENDED
- is_logical = lambda p: p.type == parted.PARTITION_LOGICAL
-
- partitions = []
- for p in src_disk.partitions:
- g = p.geometry
- f = p.fileSystem
- partitions.append(self._Partition(p.number, g.start, g.end,
- p.type, f.type if f is not None else '',
- mount_options(p.path)))
-
- last = partitions[-1]
- new_end = src_disk.device.getLength()
- if last.fs == 'linux-swap(v1)':
- MB = 2 ** 20
- size = (last.end - last.start + 1) * \
- src_disk.device.sectorSize
- meta['SWAP'] = "%d:%s" % (last.num, (size + MB - 1) // MB)
-
- img_disk.deletePartition(
- image_disk.getPartitionBySector(last.start))
- img_disk.commit()
-
- if is_logical(last) and last.num == 5:
- extended = image_disk.getExtendedPartition()
- image_disk.deletePartition(extended)
- image_disk.commit()
- partitions.remove(filter(is_extended, partitions)[0])
-
- partitions.remove(last)
- last = partitions[-1]
-
- # Leave 2048 blocks at the end
- new_end = last.end + 2048
-
- if last.mpoint:
- stat = os.statvfs(last.mpoint)
- # Shrink the last partition. The new size should be the
- # size of the occupied blocks
- blcks = stat.f_blocks - stat.f_bavail
- new_size = (blcks * stat.f_frsize) // src_dev.sectorSize
-
- # Add 10% just to be on the safe side
- part_end = last.start + (new_size * 11) // 10
- # Alighn to 2048
- part_end = ((part_end + 2047) // 2048) * 2048
- last = last._replace(end=part_end)
- partitions[-1] = last
-
- # Leave 2048 blocks at the end.
- new_end = new_size + 2048
-
- image_disk.setPartitionGeometry(
- image_disk.getPartitionBySector(last.start),
- parted.Constraint(device=image_disk.device),
- start=last.start, end=last.end)
- image_disk.commit()
-
- if last.type == parted.PARTITION_LOGICAL:
- # Fix the extended partition
- extended = disk.getExtendedPartition()
-
- image_disk.setPartitionGeometry(extended,
- parted.Constraint(device=img_dev),
- ext.geometry.start, end=last.end)
- image_disk.commit()
- finally:
- image_disk.destroy()
+ size = end - start + 1
+ os.write(tablefd, "0 %d linear %s %d" % (size, dev, start))
+ dmsetup('create', "%sp%d" % (name, num), table)
finally:
- image_dev.destroy()
-
- # Check if the available space is enough to host the image
- location = os.path.dirname(image_file)
- size = (new_end + 1) * src_disk.device.sectorSize
- self.out.output("Examining available space in %s" % location, False)
- stat = os.statvfs(location)
- available = stat.f_bavail * stat.f_frsize
- if available <= size:
- raise FatalError('Not enough space in %s to host the image' % \
- location)
- out.success("sufficient")
+ os.unlink(table)
- return partitions
+ return "/dev/mapper/%sp%d" % (name, num)
- def _fill_partitions(src_disk, image, partitions):
- pass
+ def _unmap_partition(self, dev):
+ """Unmap a previously mapped partition"""
+ if not os.path.exists(dev):
+ return
- def create_image():
+ try_fail_repeat(dmsetup, 'remove', dev.split('/dev/mapper/')[1])
+
+ def _mount(self, target, devs):
+ """Mount a list of filesystems in mountpoints relative to target"""
+ devs.sort(key=lambda d: d[1])
+ for dev, mpoint in devs:
+ absmpoint = os.path.abspath(target + mpoint)
+ if not os.path.exists(absmpoint):
+ os.makedirs(absmpoint)
+ mount(dev, absmpoint)
+
+ def _umount_all(self, target):
+ """Unmount all filesystems that are mounted under the directory target
+ """
+ mpoints = []
+ for entry in self._read_fstable('/proc/mounts'):
+ if entry.mpoint.startswith(os.path.abspath(target)):
+ mpoints.append(entry.mpoint)
+
+ mpoints.sort()
+ for mpoint in reversed(mpoints):
+ try_fail_repeat(umount, mpoint)
+
+ def _to_exclude(self):
+ """Find which directories to exclude during the image copy. This is
+ accompliced by checking which directories serve as mount points for
+ virtual file systems
+ """
+ excluded = ['/tmp', '/var/tmp']
+ if self.tmp is not None:
+ excluded.append(self.tmp)
+ local_filesystems = MKFS_OPTS.keys() + ['rootfs']
+ for entry in self._read_fstable('/proc/mounts'):
+ if entry.fs in local_filesystems:
+ continue
- image_file = '/mnt/%s.diskdump' % uuid.uuid4().hex
+ mpoint = entry.mpoint
+ if mpoint in excluded:
+ continue
- src_dev = parted.Device(self.disk)
- try:
- size = src_dev.getLength() * src_dev.sectorSize
+ descendants = filter(
+ lambda p: p.startswith(mpoint + '/'), excluded)
+ if len(descendants):
+ for d in descendants:
+ excluded.remove(d)
+ excluded.append(mpoint)
+ continue
- # Create sparse file to host the image
- truncate("-s", "%d" % disk_size, image_file)
+ dirname = mpoint
+ basename = ''
+ found_ancestor = False
+ while dirname != '/':
+ (dirname, basename) = os.path.split(dirname)
+ if dirname in excluded:
+ found_ancestor = True
+ break
+
+ if not found_ancestor:
+ excluded.append(mpoint)
+
+ return excluded
+
+ def _replace_uuids(self, target, new_uuid):
+ """Replace UUID references in various files. This is needed after
+ copying system files of the host into a new filesystem
+ """
+
+ files = ['/etc/fstab',
+ '/boot/grub/grub.cfg',
+ '/boot/grub/menu.lst',
+ '/boot/grub/grub.conf']
+
+ orig = {}
+ for p in self.disk.partitions:
+ if p.number in new_uuid.keys():
+ orig[p.number] = \
+ blkid('-s', 'UUID', '-o', 'value', p.path).stdout.strip()
+
+ for f in map(lambda f: target + f, files):
+ if not os.path.exists(f):
+ continue
- src_disk = parted.Disk(src_dev)
+ with open(f, 'r') as src:
+ lines = src.readlines()
+ with open(f, 'w') as dest:
+ for line in lines:
+ for i, uuid in new_uuid.items():
+ line = re.sub(orig[i], uuid, line)
+ dest.write(line)
+
+ def _create_filesystems(self, image, partitions):
+ """Fill the image with data. Host file systems that are not currently
+ mounted are binary copied into the image. For mounted file systems, a
+ file system level copy is performed.
+ """
+
+ filesystem = {}
+ for p in self.disk.partitions:
+ filesystem[p.number] = self._get_mount_options(p.path)
+
+ unmounted = filter(lambda p: filesystem[p.num] is None, partitions)
+ mounted = filter(lambda p: filesystem[p.num] is not None, partitions)
+
+ # For partitions that are not mounted right now, we can simply dd them
+ # into the image.
+ for p in unmounted:
+ self.out.output('Cloning partition %d ... ' % p.num, False)
+ dd('if=%s' % self.disk.device.path, 'of=%s' % image,
+ 'count=%d' % (p.end - p.start + 1), 'conv=notrunc',
+ 'seek=%d' % p.start, 'skip=%d' % p.start)
+ self.out.success("done")
+
+ loop = str(losetup('-f', '--show', image)).strip()
+ mapped = {}
+ try:
+ for p in mounted:
+ i = p.num
+ mapped[i] = self._map_partition(loop, i, p.start, p.end)
+
+ new_uuid = {}
+ # Create the file systems
+ for i, dev in mapped.iteritems():
+ fs = filesystem[i].fs
+ self.out.output('Creating %s filesystem on partition %d ... ' %
+ (fs, i), False)
+ get_command('mkfs.%s' % fs)(*(MKFS_OPTS[fs] + [dev]))
+ self.out.success('done')
+ new_uuid[i] = blkid(
+ '-s', 'UUID', '-o', 'value', dev).stdout.strip()
+
+ target = tempfile.mkdtemp()
try:
- self._create_partition_table(src_disk, image_file)
- partitions = self._shrink_partitions(src_disk, image_file)
- self.fill_partitions(src_disk, image_file, partitions)
+ self._mount(
+ target,
+ [(mapped[i], filesystem[i].mpoint) for i in mapped.keys()])
+
+ excluded = self._to_exclude()
+
+ rsync = Rsync(self.out)
+
+ for excl in excluded + [image]:
+ rsync.exclude(excl)
+
+ rsync.archive().hard_links().xattrs().sparse().acls()
+ rsync.run('/', target, 'host', 'temporary image')
+
+ # Create missing mountpoints. Since they are mountpoints, we
+ # cannot determine the ownership and the mode of the real
+ # directory. Make them inherit those properties from their
+ # parent dir
+ for excl in excluded:
+ dirname = os.path.dirname(excl)
+ stat = os.stat(dirname)
+ os.mkdir(target + excl)
+ os.chmod(target + excl, stat.st_mode)
+ os.chown(target + excl, stat.st_uid, stat.st_gid)
+
+ # /tmp and /var/tmp are special cases. We exclude then even if
+ # they aren't mountpoints. Restore their permissions.
+ for excl in ('/tmp', '/var/tmp'):
+ if self._is_mpoint(excl):
+ os.chmod(target + excl, 041777)
+ os.chown(target + excl, 0, 0)
+ else:
+ stat = os.stat(excl)
+ os.chmod(target + excl, stat.st_mode)
+ os.chown(target + excl, stat.st_uid, stat.st_gid)
+
+ # We need to replace the old UUID referencies with the new
+ # ones in grub configuration files and /etc/fstab for file
+ # systems that have been recreated.
+ self._replace_uuids(target, new_uuid)
finally:
- src_disk.destroy()
+ self._umount_all(target)
+ os.rmdir(target)
finally:
- src_dev.destroy()
+ for dev in mapped.values():
+ self._unmap_partition(dev)
+ losetup('-d', loop)
- return image_file
+ def create_image(self, image):
+ """Given an image filename, this method will create an image out of the
+ running system.
+ """
-# unmounted = filter(lambda p: not p.mopts.mpoint, partitions)
-# mounted = filter(lambda p: p.mopts.mpoint, partitions)
-#
-# for p in unmounted:
-# dd('if=%s' % src_dev.path, 'of=%s' % img_dev.path,
-# 'count=%d' % (p.end - p.start + 1), 'conv=notrunc',
-# 'seek=%d' % p.start, 'skip=%d' % p.start)
-#
-# partition_devices = create_devices(dest, partitions)
-#
-# mounted.sort(key=lambda p: p.mopts.mpoint)
-#
-# return img
+ size = self.disk.device.length * self.disk.device.sectorSize
+
+ # Create sparse file to host the image
+ fd = os.open(image, os.O_WRONLY | os.O_CREAT)
+ try:
+ os.ftruncate(fd, size)
+ finally:
+ os.close(fd)
+
+ self._create_partition_table(image)
+ end_sector, partitions = self._shrink_partitions(image)
+
+ if self.disk.type == 'gpt':
+ old_size = size
+ size = (end_sector + 1) * self.disk.device.sectorSize
+ ptable = GPTPartitionTable(image)
+ size = ptable.shrink(size, old_size)
+ else:
+ # Alighn to 2048
+ end_sector = ((end_sector + 2047) // 2048) * 2048
+ size = (end_sector + 1) * self.disk.device.sectorSize
+
+ # Truncate image to the new size.
+ fd = os.open(image, os.O_RDWR)
+ try:
+ os.ftruncate(fd, size)
+ finally:
+ os.close(fd)
+
+ # Check if the available space is enough to host the image
+ dirname = os.path.dirname(image)
+ self.out.output("Examining available space ...", False)
+ if free_space(dirname) <= size:
+ raise FatalError("Not enough space under %s to host the temporary "
+ "image" % dirname)
+ self.out.success("sufficient")
+
+ self._create_filesystems(image, partitions)
+
+ return image
# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :