#!/usr/bin/env python
-import losetup
+from image_creator.util import get_command
+from image_creator import FatalError
+from clint.textui import progress
+
import stat
import os
import tempfile
import re
import sys
import guestfs
-
-from pbs import dmsetup
-from pbs import blockdev
-from pbs import dd
+import time
class DiskError(Exception):
pass
+dd = get_command('dd')
+dmsetup = get_command('dmsetup')
+losetup = get_command('losetup')
+blockdev = get_command('blockdev')
+
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
self._cleanup_jobs.append((job, args))
def _losetup(self, fname):
- loop = losetup.find_unused_loop_device()
- loop.mount(fname)
- self._add_cleanup(loop.unmount)
- return loop.device
+ loop = losetup('-f', '--show', fname)
+ loop = loop.strip() # remove the new-line char
+ self._add_cleanup(losetup, '-d', loop)
+ return loop
def _dir_to_disk(self):
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):
# Take a snapshot and return it to the user
size = blockdev('--getsize', sourcedev)
cowfd, cow = tempfile.mkstemp()
+ os.close(cowfd)
self._add_cleanup(os.unlink, cow)
# Create 1G cow sparse file
dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', 'seek=%d' % (1024 * 1024))
self._add_cleanup(dmsetup, 'remove', snapshot)
finally:
os.unlink(table)
-
new_device = DiskDevice("/dev/mapper/%s" % snapshot)
self._devices.append(new_device)
+ new_device.enable()
return new_device
def destroy_device(self, device):
+ """Destroys a DiskDevice instance previously created by
+ get_device method.
+ """
self._devices.remove(device)
device.destroy()
+def progress_generator(label=''):
+ position = 0;
+ for i in progress.bar(range(100),label):
+ if i < position:
+ continue
+ position = yield
+ yield #suppress the StopIteration exception
+
+
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.progress_bar = None
self.g = guestfs.GuestFS()
+ self.g.add_drive_opts(self.device, readonly=0)
+
+ #self.g.set_trace(1)
+ #self.g.set_verbose(1)
- self.g.set_trace(1)
+ self.guestfs_enabled = False
+
+ def enable(self):
+ """Enable a newly created DiskDevice"""
- self.g.add_drive_opts(device, readonly=0)
+ self.progressbar = progress_generator("VM lauch: ")
+ self.progressbar.next()
+ eh = self.g.set_event_callback(self.progress_callback, guestfs.EVENT_PROGRESS)
self.g.launch()
+ self.guestfs_enabled = True
+ self.g.delete_event_callback(eh)
+ if self.progressbar is not None:
+ self.progressbar.send(100)
+ self.progressbar = None
+
roots = self.g.inspect_os()
if len(roots) == 0:
- raise DiskError("No operating system found")
+ raise FatalError("No operating system found")
if len(roots) > 1:
- raise DiskError("Multiple operating systems found")
+ raise FatalError("Multiple operating systems found")
self.root = roots[0]
self.ostype = self.g.inspect_get_type(self.root)
self.distro = self.g.inspect_get_distro(self.root)
def destroy(self):
- self.g.umount_all()
- self.g.sync()
- # Close the guestfs handler
+ """Destroy this DiskDevice instance."""
+
+ if self.guestfs_enabled:
+ self.g.umount_all()
+ self.g.sync()
+
+ # Close the guestfs handler if open
self.g.close()
- del self.g
+
+ def progress_callback(self, ev, eh, buf, array):
+ position = array[2]
+ total = array[3]
+
+ self.progressbar.send((position * 100)//total)
+
+ if position == total:
+ self.progressbar = None
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':
- raise DiskError("You have a %s partition table. "
+ raise FatalError("You have a %s partition table. "
"Only msdos partitions are supported" % parttype)
last_partition = self.g.part_list(dev)[-1]
if last_partition['part_num'] > 4:
- raise DiskError("This disk contains logical partitions. "
+ raise FatalError("This disk contains logical partitions. "
"Only primary partitions are supported.")
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']
# vim: set sta sts=4 shiftwidth=4 sw=4 et ai :
projects / snf-image-creator / blobdiff