class Disk(object):
+ """This class represents a hard disk hosting an Operating System
+
+ A Disk instance never alters the source media it is created from.
+ Any change is done on a snapshot created by the device-mapper of
+ the Linux kernel.
+ """
def __init__(self, source):
+ """Create a new Disk instance out of a source media. The source
+ media can be an image file, a block device or a directory."""
self._cleanup_jobs = []
self._devices = []
self.source = source
raise NotImplementedError
def cleanup(self):
+ """Cleanup internal data. This needs to be called before the
+ program ends.
+ """
while len(self._devices):
device = self._devices.pop()
device.destroy()
job(*args)
def get_device(self):
+ """Returns a newly created DiskDevice instance.
+
+ This instance is a snapshot of the original source media of
+ the Disk instance.
+ """
sourcedev = self.source
mode = os.stat(self.source).st_mode
if stat.S_ISDIR(mode):
return new_device
def destroy_device(self, device):
+ """Destroys a DiskDevice instance previously created by
+ get_device method.
+ """
self._devices.remove(device)
device.destroy()
class DiskDevice(object):
+ """This class represents a block device hosting an Operating System
+ as created by the device-mapper.
+ """
def __init__(self, device, bootable=True):
+ """Create a new DiskDevice."""
self.device = device
self.bootable = bootable
self.distro = self.g.inspect_get_distro(self.root)
def destroy(self):
+ """Destroy this DiskDevice instance."""
self.g.umount_all()
self.g.sync()
# Close the guestfs handler
self.g.close()
- del self.g
def mount(self):
+ """Mount all disk partitions in a correct order."""
mps = self.g.inspect_get_mountpoints(self.root)
# Sort the keys to mount the fs in a correct order.
print "%s (ignored)" % msg
def umount(self):
+ """Umount all mounted filesystems."""
self.g.umount_all()
def shrink(self):
+ """Shrink the disk.
+
+ This is accomplished by shrinking the last filesystem in the
+ disk and then updating the partition table. The new disk size
+ (in bytes) is returned.
+ """
dev = self.g.part_to_dev(self.root)
parttype = self.g.part_get_parttype(dev)
if parttype != 'msdos':
part_dev = "%s%d" % (dev, last_partition['part_num'])
fs_type = self.g.vfs_type(part_dev)
if not re.match("ext[234]", fs_type):
- print "Warning, don't know how to resize %s partitions" % vfs_type
+ print "Warning: Don't know how to resize %s partitions." % vfs_type
return
self.g.e2fsck_f(part_dev)
start = last_partition['part_start'] / sector_size
end = start + (block_size * block_cnt) / sector_size - 1
+ self.g.part_del(dev, last_partition['part_num'])
+ self.g.part_add(dev, 'p', start, end)
+
return (end + 1) * sector_size
+ def size(self):
+ """Returns the "payload" size of the device.
+
+ The size returned by this method is the size of the space occupied by
+ the partitions (including the space before the first partition).
+ """
+ dev = self.g.part_to_dev(self.root)
+ last = self.g.part_list(dev)[-1]
+ return last['part_end']
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