import os
import re
import tempfile
+import uuid
from collections import namedtuple
import parted
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')
dd = get_command('dd')
self.disk = parted.Disk(device)
def _read_fstable(self, f):
+ """Use this generator to iterate over the lines of and fstab file"""
if not os.path.isfile(f):
raise FatalError("Unable to open: `%s'. File is missing." % f)
yield FileSystemTableEntry(*entry)
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(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 _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
return None
def _create_partition_table(self, image):
-
- if self.disk.type != 'msdos':
- raise FatalError('Only msdos partition tables are supported')
+ """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.
+ # 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' % 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 = self.disk.getExtendedPartition()
if not extended:
start = logical[i].geometry.end + 1
def _get_partitions(self, disk):
+ """Returns a list with the partitions of the provided disk"""
Partition = namedtuple('Partition', 'num start end type fs')
partitions = []
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_dev = parted.Device(image)
- image_disk = parted.Disk(image_dev)
+ 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
image_disk.deletePartition(
image_disk.getPartitionBySector(last.start))
- image_disk.commit()
+ image_disk.commitToDevice()
if is_logical(last) and last.num == 5:
extended = image_disk.getExtendedPartition()
image_disk.deletePartition(extended)
- image_disk.commit()
+ image_disk.commitToDevice()
partitions.remove(filter(is_extended, partitions)[0])
partitions.remove(last)
last = partitions[-1]
- # Leave 2048 blocks at the end
- new_end = last.end + 2048
+ new_end = last.end
mount_options = self._get_mount_options(
self.disk.getPartitionBySector(last.start).path)
# 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),
- parted.Constraint(device=image_disk.device),
+ image_disk.getPartitionBySector(last.start), constraint,
start=last.start, end=part_end)
- image_disk.commit()
+ 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
- # Leave 2048 blocks at the end.
- new_end = part_end + 2048
+ new_end = part_end
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()
+ image_disk.minimizeExtendedPartition()
- image_dev.destroy()
- return new_end
+ return (new_end, self._get_partitions(image_disk))
def _map_partition(self, dev, num, start, end):
- name = os.path.basename(dev)
+ """Map a partition into a block device using the device mapper"""
+ name = os.path.basename(dev) + "_" + uuid.uuid4().hex
tablefd, table = tempfile.mkstemp()
try:
size = end - start + 1
return "/dev/mapper/%sp%d" % (name, num)
def _unmap_partition(self, dev):
+ """Unmap a previously mapped partition"""
if not os.path.exists(dev):
return
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)
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)):
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)
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 = dict(map(
- lambda p: (
- p.number,
- blkid('-s', 'UUID', '-o', 'value', p.path).stdout.strip()),
- self.disk.partitions))
+ 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
line = re.sub(orig[i], uuid, line)
dest.write(line)
- def _create_filesystems(self, image):
+ 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)
- partitions = self._get_partitions(parted.Disk(parted.Device(image)))
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 = {}
target = tempfile.mkdtemp()
try:
- absmpoints = self._mount(target,
- [(mapped[i], filesystem[i].mpoint)
- for i in mapped.keys()])
+ self._mount(
+ target,
+ [(mapped[i], filesystem[i].mpoint) for i in mapped.keys()])
+
excluded = self._to_exclude()
rsync = Rsync(self.out)
- # Excluded paths need to be relative to the source
- for excl in map(lambda p: p[1:], excluded + [image]):
+ for excl in excluded + [image]:
rsync.exclude(excl)
rsync.archive().hard_links().xattrs().sparse().acls()
# 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, stat.st_mode)
- os.chown(target + excl, stat.st_uid, stat.st_gid)
+ 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
os.close(fd)
self._create_partition_table(image)
-
- end_sector = self._shrink_partitions(image)
-
- size = (end_sector + 1) * self.disk.device.sectorSize
+ 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)
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 image' %
- dirname)
+ raise FatalError("Not enough space under %s to host the temporary "
+ "image" % dirname)
self.out.success("sufficient")
- self._create_filesystems(image)
+ self._create_filesystems(image, partitions)
return image
projects / snf-image-creator / blobdiff