X-Git-Url: https://code.grnet.gr/git/snf-image-creator/blobdiff_plain/3ccb2618f3728bb7457e4e870753eeec833ea17c..e22aa3a9da0dbf00ac43fa3c5964c9688a1b6cb7:/image_creator/disk.py diff --git a/image_creator/disk.py b/image_creator/disk.py index 809a1a3..ef53799 100644 --- a/image_creator/disk.py +++ b/image_creator/disk.py @@ -1,7 +1,38 @@ -#!/usr/bin/env python +# Copyright 2012 GRNET S.A. All rights reserved. +# +# Redistribution and use in source and binary forms, with or +# without modification, are permitted provided that the following +# conditions are met: +# +# 1. Redistributions of source code must retain the above +# copyright notice, this list of conditions and the following +# disclaimer. +# +# 2. Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following +# disclaimer in the documentation and/or other materials +# provided with the distribution. +# +# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS +# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED +# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +# POSSIBILITY OF SUCH DAMAGE. +# +# The views and conclusions contained in the software and +# documentation are those of the authors and should not be +# interpreted as representing official policies, either expressed +# or implied, of GRNET S.A. from image_creator.util import get_command -from clint.textui import progress +from image_creator.util import warn, progress, success, output, FatalError import stat import os @@ -10,6 +41,8 @@ import uuid import re import sys import guestfs +import time +from sendfile import sendfile class DiskError(Exception): @@ -41,7 +74,7 @@ class Disk(object): def _losetup(self, fname): loop = losetup('-f', '--show', fname) - loop = loop.strip() # remove the new-line char + loop = loop.strip() # remove the new-line char self._add_cleanup(losetup, '-d', loop) return loop @@ -60,27 +93,35 @@ class Disk(object): job, args = self._cleanup_jobs.pop() 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. + def snapshot(self): + """Creates a snapshot of the original source media of the Disk + instance. """ + + output("Examining source media `%s'..." % self.source, False) sourcedev = self.source mode = os.stat(self.source).st_mode if stat.S_ISDIR(mode): + success('looks like a directory') return self._losetup(self._dir_to_disk()) elif stat.S_ISREG(mode): + success('looks like an image file') sourcedev = self._losetup(self.source) elif not stat.S_ISBLK(mode): - raise ValueError("Value for self.source is invalid") + raise ValueError("Invalid media source. Only block devices, " + "regular files and directories are supported.") + else: + success('looks like a block device') # Take a snapshot and return it to the user + output("Snapshotting media source...", False) 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)) + dd('if=/dev/null', 'of=%s' % cow, 'bs=1k', \ + 'seek=%d' % (1024 * 1024)) cowdev = self._losetup(cow) snapshot = uuid.uuid4().hex @@ -90,11 +131,22 @@ class Disk(object): (int(size), sourcedev, cowdev)) dmsetup('create', snapshot, table) self._add_cleanup(dmsetup, 'remove', snapshot) + # Sometimes dmsetup remove fails with Device or resource busy, + # although everything is cleaned up and the snapshot is not + # used by anyone. Add a 2 seconds delay to be on the safe side. + self._add_cleanup(time.sleep, 2) + finally: os.unlink(table) + success('done') + return "/dev/mapper/%s" % snapshot - new_device = DiskDevice("/dev/mapper/%s" % snapshot) + def get_device(self, media): + """Returns a newly created DiskDevice instance.""" + + new_device = DiskDevice(media) self._devices.append(new_device) + new_device.enable() return new_device def destroy_device(self, device): @@ -105,15 +157,6 @@ class Disk(object): device.destroy() -def progress_generator(total): - position = 0; - for i in progress.bar(range(total)): - 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. @@ -121,52 +164,67 @@ class DiskDevice(object): 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(device, readonly=0) + self.g.add_drive_opts(self.device, readonly=0) #self.g.set_trace(1) #self.g.set_verbose(1) - eh = self.g.set_event_callback(self.progress_callback, guestfs.EVENT_PROGRESS) + self.guestfs_enabled = False + + def enable(self): + """Enable a newly created DiskDevice""" + self.progressbar = progress("Launching helper VM: ") + 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 + + output('Inspecting Operating System...', False) 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." + "We only support images with one filesystem.") self.root = roots[0] self.ostype = self.g.inspect_get_type(self.root) self.distro = self.g.inspect_get_distro(self.root) + success('found a %s system' % self.distro) def destroy(self): """Destroy this DiskDevice instance.""" - self.g.umount_all() - self.g.sync() - # Close the guestfs handler + + if self.guestfs_enabled: + self.g.umount_all() + self.g.sync() + + # Close the guestfs handler if open self.g.close() def progress_callback(self, ev, eh, buf, array): position = array[2] total = array[3] - - if self.progress_bar is None: - self.progress_bar = progress_generator(total) - self.progress_bar.next() - self.progress_bar.send(position) + self.progressbar.send((position * 100) // total) if position == total: - self.progress_bar = None + self.progressbar = None def mount(self): """Mount all disk partitions in a correct order.""" + + output("Mounting image...", False) mps = self.g.inspect_get_mountpoints(self.root) # Sort the keys to mount the fs in a correct order. @@ -183,7 +241,8 @@ class DiskDevice(object): try: self.g.mount(dev, mp) except RuntimeError as msg: - print "%s (ignored)" % msg + warn("%s (ignored)" % msg) + success("done") def umount(self): """Umount all mounted filesystems.""" @@ -196,29 +255,34 @@ class DiskDevice(object): disk and then updating the partition table. The new disk size (in bytes) is returned. """ + output("Shrinking image (this may take a while)...", False) + 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 + warn("Don't know how to resize %s partitions." % vfs_type) return self.g.e2fsck_f(part_dev) self.g.resize2fs_M(part_dev) - output = self.g.tune2fs_l(part_dev) - block_size = int(filter(lambda x: x[0] == 'Block size', output)[0][1]) - block_cnt = int(filter(lambda x: x[0] == 'Block count', output)[0][1]) + + out = self.g.tune2fs_l(part_dev) + block_size = int( + filter(lambda x: x[0] == 'Block size', out)[0][1]) + block_cnt = int( + filter(lambda x: x[0] == 'Block count', out)[0][1]) sector_size = self.g.blockdev_getss(dev) @@ -228,7 +292,10 @@ class DiskDevice(object): self.g.part_del(dev, last_partition['part_num']) self.g.part_add(dev, 'p', start, end) - return (end + 1) * sector_size + new_size = (end + 1) * sector_size + success("new image size is %dMB" % + ((new_size + 2 ** 20 - 1) // 2 ** 20)) + return new_size def size(self): """Returns the "payload" size of the device. @@ -239,6 +306,39 @@ class DiskDevice(object): dev = self.g.part_to_dev(self.root) last = self.g.part_list(dev)[-1] - return last['part_end'] + return last['part_end'] + 1 + + def dump(self, outfile): + """Dumps the content of device into a file. + + This method will only dump the actual payload, found by reading the + partition table. Empty space in the end of the device will be ignored. + """ + blocksize = 2 ** 22 # 4MB + size = self.size() + progress_size = (size + 2 ** 20 - 1) // 2 ** 20 # in MB + progressbar = progress("Dumping image file: ", progress_size) + + source = open(self.device, "r") + try: + dest = open(outfile, "w") + try: + left = size + offset = 0 + progressbar.next() + while left > 0: + length = min(left, blocksize) + sent = sendfile(dest.fileno(), source.fileno(), offset, + length) + offset += sent + left -= sent + for i in range((length + 2 ** 20 - 1) // 2 ** 20): + progressbar.next() + finally: + dest.close() + finally: + source.close() + + success('Image file %s was successfully created' % outfile) # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :