# Copyright 2010 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # All Rights Reserved. # Copyright (c) 2010 Citrix Systems, Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. """ Helper methods to deal with images. This is essentially a copy from nova.virt.images.py Some slight modifications, but at some point we should look at maybe pushing this up to Oslo """ import contextlib import errno import math import os import re import tempfile from oslo_concurrency import processutils from oslo_config import cfg from oslo_log import log as logging from oslo_utils import fileutils from oslo_utils import imageutils from oslo_utils import timeutils from oslo_utils import units import psutil from cinder import exception from cinder.i18n import _ from cinder import utils from cinder.volume import throttling from cinder.volume import utils as volume_utils LOG = logging.getLogger(__name__) image_helper_opts = [cfg.StrOpt('image_conversion_dir', default='$state_path/conversion', help='Directory used for temporary storage ' 'during image conversion'), ] CONF = cfg.CONF CONF.register_opts(image_helper_opts) QEMU_IMG_LIMITS = processutils.ProcessLimits( cpu_time=8, address_space=1 * units.Gi) # NOTE(abhishekk): qemu-img convert command supports raw, qcow2, qed, # vdi, vmdk, vhd and vhdx disk-formats but glance doesn't support qed # disk-format. # Ref: http://docs.openstack.org/image-guide/convert-images.html VALID_DISK_FORMATS = ('raw', 'vmdk', 'vdi', 'qcow2', 'vhd', 'vhdx', 'parallels') def validate_disk_format(disk_format): return disk_format in VALID_DISK_FORMATS def qemu_img_info(path, run_as_root=True): """Return an object containing the parsed output from qemu-img info.""" cmd = ['env', 'LC_ALL=C', 'qemu-img', 'info', path] if os.name == 'nt': cmd = cmd[2:] out, _err = utils.execute(*cmd, run_as_root=run_as_root, prlimit=QEMU_IMG_LIMITS) info = imageutils.QemuImgInfo(out) # From Cinder's point of view, any 'luks' formatted images # should be treated as 'raw'. if info.file_format == 'luks': info.file_format = 'raw' return info def get_qemu_img_version(): info = utils.execute('qemu-img', '--version', check_exit_code=False)[0] pattern = r"qemu-img version ([0-9\.]*)" version = re.match(pattern, info) if not version: LOG.warning("qemu-img is not installed.") return None return _get_version_from_string(version.groups()[0]) def _get_version_from_string(version_string): return [int(x) for x in version_string.split('.')] def check_qemu_img_version(minimum_version): qemu_version = get_qemu_img_version() if (qemu_version is None or qemu_version < _get_version_from_string(minimum_version)): if qemu_version: current_version = '.'.join((str(element) for element in qemu_version)) else: current_version = None _msg = _('qemu-img %(minimum_version)s or later is required by ' 'this volume driver. Current qemu-img version: ' '%(current_version)s') % {'minimum_version': minimum_version, 'current_version': current_version} raise exception.VolumeBackendAPIException(data=_msg) def _convert_image(prefix, source, dest, out_format, src_format=None, run_as_root=True): """Convert image to other format.""" cmd = prefix + ('qemu-img', 'convert', '-O', out_format, source, dest) # Check whether O_DIRECT is supported and set '-t none' if it is # This is needed to ensure that all data hit the device before # it gets unmapped remotely from the host for some backends # Reference Bug: #1363016 # NOTE(jdg): In the case of file devices qemu does the # flush properly and more efficiently than would be done # setting O_DIRECT, so check for that and skip the # setting for non BLK devs if (utils.is_blk_device(dest) and volume_utils.check_for_odirect_support(source, dest, 'oflag=direct')): cmd = prefix + ('qemu-img', 'convert', '-t', 'none') # AMI images can be raw or qcow2 but qemu-img doesn't accept "ami" as # an image format, so we use automatic detection. # TODO(geguileo): This fixes unencrypted AMI image case, but we need to # fix the encrypted case. if (src_format or '').lower() not in ('', 'ami'): cmd += ('-f', src_format) # prevent detection of format cmd += ('-O', out_format, source, dest) start_time = timeutils.utcnow() utils.execute(*cmd, run_as_root=run_as_root) duration = timeutils.delta_seconds(start_time, timeutils.utcnow()) # NOTE(jdg): use a default of 1, mostly for unit test, but in # some incredible event this is 0 (cirros image?) don't barf if duration < 1: duration = 1 try: image_size = qemu_img_info(source, run_as_root=run_as_root).virtual_size except ValueError as e: msg = ("The image was successfully converted, but image size " "is unavailable. src %(src)s, dest %(dest)s. %(error)s") LOG.info(msg, {"src": source, "dest": dest, "error": e}) return fsz_mb = image_size / units.Mi mbps = (fsz_mb / duration) msg = ("Image conversion details: src %(src)s, size %(sz).2f MB, " "duration %(duration).2f sec, destination %(dest)s") LOG.debug(msg, {"src": source, "sz": fsz_mb, "duration": duration, "dest": dest}) msg = "Converted %(sz).2f MB image at %(mbps).2f MB/s" LOG.info(msg, {"sz": fsz_mb, "mbps": mbps}) def convert_image(source, dest, out_format, src_format=None, run_as_root=True, throttle=None): if not throttle: throttle = throttling.Throttle.get_default() with throttle.subcommand(source, dest) as throttle_cmd: _convert_image(tuple(throttle_cmd['prefix']), source, dest, out_format, src_format=src_format, run_as_root=run_as_root) def resize_image(source, size, run_as_root=False): """Changes the virtual size of the image.""" cmd = ('qemu-img', 'resize', source, '%sG' % size) utils.execute(*cmd, run_as_root=run_as_root) def fetch(context, image_service, image_id, path, _user_id, _project_id): # TODO(vish): Improve context handling and add owner and auth data # when it is added to glance. Right now there is no # auth checking in glance, so we assume that access was # checked before we got here. start_time = timeutils.utcnow() with fileutils.remove_path_on_error(path): with open(path, "wb") as image_file: try: image_service.download(context, image_id, image_file) except IOError as e: if e.errno == errno.ENOSPC: params = {'path': os.path.dirname(path), 'image': image_id} reason = _("No space left in image_conversion_dir " "path (%(path)s) while fetching " "image %(image)s.") % params LOG.exception(reason) raise exception.ImageTooBig(image_id=image_id, reason=reason) duration = timeutils.delta_seconds(start_time, timeutils.utcnow()) # NOTE(jdg): use a default of 1, mostly for unit test, but in # some incredible event this is 0 (cirros image?) don't barf if duration < 1: duration = 1 fsz_mb = os.stat(image_file.name).st_size / units.Mi mbps = (fsz_mb / duration) msg = ("Image fetch details: dest %(dest)s, size %(sz).2f MB, " "duration %(duration).2f sec") LOG.debug(msg, {"dest": image_file.name, "sz": fsz_mb, "duration": duration}) msg = "Image download %(sz).2f MB at %(mbps).2f MB/s" LOG.info(msg, {"sz": fsz_mb, "mbps": mbps}) def get_qemu_data(image_id, has_meta, disk_format_raw, dest, run_as_root): # We may be on a system that doesn't have qemu-img installed. That # is ok if we are working with a RAW image. This logic checks to see # if qemu-img is installed. If not we make sure the image is RAW and # throw an exception if not. Otherwise we stop before needing # qemu-img. Systems with qemu-img will always progress through the # whole function. try: # Use the empty tmp file to make sure qemu_img_info works. data = qemu_img_info(dest, run_as_root=run_as_root) # There are a lot of cases that can cause a process execution # error, but until we do more work to separate out the various # cases we'll keep the general catch here except processutils.ProcessExecutionError: data = None if has_meta: if not disk_format_raw: raise exception.ImageUnacceptable( reason=_("qemu-img is not installed and image is of " "type %s. Only RAW images can be used if " "qemu-img is not installed.") % disk_format_raw, image_id=image_id) else: raise exception.ImageUnacceptable( reason=_("qemu-img is not installed and the disk " "format is not specified. Only RAW images " "can be used if qemu-img is not installed."), image_id=image_id) return data def fetch_verify_image(context, image_service, image_id, dest, user_id=None, project_id=None, size=None, run_as_root=True): fetch(context, image_service, image_id, dest, None, None) image_meta = image_service.show(context, image_id) with fileutils.remove_path_on_error(dest): has_meta = False if not image_meta else True try: format_raw = True if image_meta['disk_format'] == 'raw' else False except TypeError: format_raw = False data = get_qemu_data(image_id, has_meta, format_raw, dest, run_as_root) # We can only really do verification of the image if we have # qemu data to use if data is not None: fmt = data.file_format if fmt is None: raise exception.ImageUnacceptable( reason=_("'qemu-img info' parsing failed."), image_id=image_id) backing_file = data.backing_file if backing_file is not None: raise exception.ImageUnacceptable( image_id=image_id, reason=(_("fmt=%(fmt)s backed by: %(backing_file)s") % {'fmt': fmt, 'backing_file': backing_file})) # NOTE(xqueralt): If the image virtual size doesn't fit in the # requested volume there is no point on resizing it because it will # generate an unusable image. if size is not None and data.virtual_size > size: params = {'image_size': data.virtual_size, 'volume_size': size} reason = _("Size is %(image_size)dGB and doesn't fit in a " "volume of size %(volume_size)dGB.") % params raise exception.ImageUnacceptable(image_id=image_id, reason=reason) def fetch_to_vhd(context, image_service, image_id, dest, blocksize, user_id=None, project_id=None, run_as_root=True): fetch_to_volume_format(context, image_service, image_id, dest, 'vpc', blocksize, user_id, project_id, run_as_root=run_as_root) def fetch_to_raw(context, image_service, image_id, dest, blocksize, user_id=None, project_id=None, size=None, run_as_root=True): fetch_to_volume_format(context, image_service, image_id, dest, 'raw', blocksize, user_id, project_id, size, run_as_root=run_as_root) def fetch_to_volume_format(context, image_service, image_id, dest, volume_format, blocksize, user_id=None, project_id=None, size=None, run_as_root=True): qemu_img = True image_meta = image_service.show(context, image_id) # NOTE(avishay): I'm not crazy about creating temp files which may be # large and cause disk full errors which would confuse users. # Unfortunately it seems that you can't pipe to 'qemu-img convert' because # it seeks. Maybe we can think of something for a future version. with temporary_file() as tmp: has_meta = False if not image_meta else True try: format_raw = True if image_meta['disk_format'] == 'raw' else False except TypeError: format_raw = False data = get_qemu_data(image_id, has_meta, format_raw, tmp, run_as_root) if data is None: qemu_img = False tmp_images = TemporaryImages.for_image_service(image_service) tmp_image = tmp_images.get(context, image_id) if tmp_image: tmp = tmp_image else: fetch(context, image_service, image_id, tmp, user_id, project_id) if is_xenserver_format(image_meta): replace_xenserver_image_with_coalesced_vhd(tmp) if not qemu_img: # qemu-img is not installed but we do have a RAW image. As a # result we only need to copy the image to the destination and then # return. LOG.debug('Copying image from %(tmp)s to volume %(dest)s - ' 'size: %(size)s', {'tmp': tmp, 'dest': dest, 'size': image_meta['size']}) image_size_m = math.ceil(float(image_meta['size']) / units.Mi) volume_utils.copy_volume(tmp, dest, image_size_m, blocksize) return data = qemu_img_info(tmp, run_as_root=run_as_root) virt_size = int(math.ceil(float(data.virtual_size) / units.Gi)) # NOTE(xqueralt): If the image virtual size doesn't fit in the # requested volume there is no point on resizing it because it will # generate an unusable image. if size is not None and virt_size > size: params = {'image_size': virt_size, 'volume_size': size} reason = _("Size is %(image_size)dGB and doesn't fit in a " "volume of size %(volume_size)dGB.") % params raise exception.ImageUnacceptable(image_id=image_id, reason=reason) fmt = data.file_format if fmt is None: raise exception.ImageUnacceptable( reason=_("'qemu-img info' parsing failed."), image_id=image_id) backing_file = data.backing_file if backing_file is not None: raise exception.ImageUnacceptable( image_id=image_id, reason=_("fmt=%(fmt)s backed by:%(backing_file)s") % {'fmt': fmt, 'backing_file': backing_file, }) # NOTE(e0ne): check for free space in destination directory before # image convertion. check_available_space(dest, virt_size, image_id) # NOTE(jdg): I'm using qemu-img convert to write # to the volume regardless if it *needs* conversion or not # TODO(avishay): We can speed this up by checking if the image is raw # and if so, writing directly to the device. However, we need to keep # check via 'qemu-img info' that what we copied was in fact a raw # image and not a different format with a backing file, which may be # malicious. LOG.debug("%s was %s, converting to %s ", image_id, fmt, volume_format) if image_meta['disk_format'] == 'vhd': # qemu-img still uses the legacy 'vpc' name for vhd format. disk_format = 'vpc' else: disk_format = image_meta['disk_format'] convert_image(tmp, dest, volume_format, src_format=disk_format, run_as_root=run_as_root) data = qemu_img_info(dest, run_as_root=run_as_root) if not _validate_file_format(data, volume_format): raise exception.ImageUnacceptable( image_id=image_id, reason=_("Converted to %(vol_format)s, but format is " "now %(file_format)s") % {'vol_format': volume_format, 'file_format': data. file_format}) def _validate_file_format(image_data, expected_format): if image_data.file_format == expected_format: return True elif image_data.file_format == 'vpc' and expected_format == 'vhd': # qemu-img still uses the legacy 'vpc' name for the vhd format. return True return False def upload_volume(context, image_service, image_meta, volume_path, volume_format='raw', run_as_root=True): image_id = image_meta['id'] if (image_meta['disk_format'] == volume_format): LOG.debug("%s was %s, no need to convert to %s", image_id, volume_format, image_meta['disk_format']) if os.name == 'nt' or os.access(volume_path, os.R_OK): with open(volume_path, 'rb') as image_file: image_service.update(context, image_id, {}, image_file) else: with utils.temporary_chown(volume_path): with open(volume_path, 'rb') as image_file: image_service.update(context, image_id, {}, image_file) return with temporary_file() as tmp: LOG.debug("%s was %s, converting to %s", image_id, volume_format, image_meta['disk_format']) data = qemu_img_info(volume_path, run_as_root=run_as_root) backing_file = data.backing_file fmt = data.file_format if backing_file is not None: # Disallow backing files as a security measure. # This prevents a user from writing an image header into a raw # volume with a backing file pointing to data they wish to # access. raise exception.ImageUnacceptable( image_id=image_id, reason=_("fmt=%(fmt)s backed by:%(backing_file)s") % {'fmt': fmt, 'backing_file': backing_file}) out_format = image_meta['disk_format'] # qemu-img accepts 'vpc' as argument for vhd format if out_format == 'vhd': out_format = 'vpc' convert_image(volume_path, tmp, out_format, run_as_root=run_as_root) data = qemu_img_info(tmp, run_as_root=run_as_root) if data.file_format != out_format: raise exception.ImageUnacceptable( image_id=image_id, reason=_("Converted to %(f1)s, but format is now %(f2)s") % {'f1': out_format, 'f2': data.file_format}) with open(tmp, 'rb') as image_file: image_service.update(context, image_id, {}, image_file) def check_virtual_size(virtual_size, volume_size, image_id): virtual_size = int(math.ceil(float(virtual_size) / units.Gi)) if virtual_size > volume_size: params = {'image_size': virtual_size, 'volume_size': volume_size} reason = _("Image virtual size is %(image_size)dGB" " and doesn't fit in a volume of size" " %(volume_size)dGB.") % params raise exception.ImageUnacceptable(image_id=image_id, reason=reason) return virtual_size def check_available_space(dest, image_size, image_id): # TODO(e0ne): replace psutil with shutil.disk_usage when we drop # Python 2.7 support. if not os.path.isdir(dest): dest = os.path.dirname(dest) free_space = psutil.disk_usage(dest).free if free_space <= image_size: msg = ('There is no space to convert image. ' 'Requested: %(image_size)s, available: %(free_space)s' ) % {'image_size': image_size, 'free_space': free_space} raise exception.ImageTooBig(image_id=image_id, reason=msg) def is_xenserver_format(image_meta): return ( image_meta['disk_format'] == 'vhd' and image_meta['container_format'] == 'ovf' ) def set_vhd_parent(vhd_path, parentpath): utils.execute('vhd-util', 'modify', '-n', vhd_path, '-p', parentpath) def extract_targz(archive_name, target): utils.execute('tar', '-xzf', archive_name, '-C', target) def fix_vhd_chain(vhd_chain): for child, parent in zip(vhd_chain[:-1], vhd_chain[1:]): set_vhd_parent(child, parent) def get_vhd_size(vhd_path): out, _err = utils.execute('vhd-util', 'query', '-n', vhd_path, '-v') return int(out) def resize_vhd(vhd_path, size, journal): utils.execute( 'vhd-util', 'resize', '-n', vhd_path, '-s', '%d' % size, '-j', journal) def coalesce_vhd(vhd_path): utils.execute( 'vhd-util', 'coalesce', '-n', vhd_path) def create_temporary_file(*args, **kwargs): if (CONF.image_conversion_dir and not os.path.exists(CONF.image_conversion_dir)): os.makedirs(CONF.image_conversion_dir) fd, tmp = tempfile.mkstemp(dir=CONF.image_conversion_dir, *args, **kwargs) os.close(fd) return tmp def cleanup_temporary_file(backend_name): temp_dir = CONF.image_conversion_dir if (not temp_dir or not os.path.exists(temp_dir)): LOG.debug("Configuration image_conversion_dir is None or the path " "doesn't exist.") return try: # TODO(wanghao): Consider using os.scandir for better performance in # future when cinder only supports Python version 3.5+. files = os.listdir(CONF.image_conversion_dir) # NOTE(wanghao): For multi-backend case, if one backend was slow # starting but another backend is up and doing an image conversion, # init_host should only clean the tmp files which belongs to its # backend. for tmp_file in files: if tmp_file.endswith(backend_name): path = os.path.join(temp_dir, tmp_file) os.remove(path) except OSError as e: LOG.warning("Exception caught while clearing temporary image " "files: %s", e) @contextlib.contextmanager def temporary_file(*args, **kwargs): tmp = None try: tmp = create_temporary_file(*args, **kwargs) yield tmp finally: if tmp: fileutils.delete_if_exists(tmp) def temporary_dir(): if (CONF.image_conversion_dir and not os.path.exists(CONF.image_conversion_dir)): os.makedirs(CONF.image_conversion_dir) return utils.tempdir(dir=CONF.image_conversion_dir) def coalesce_chain(vhd_chain): for child, parent in zip(vhd_chain[:-1], vhd_chain[1:]): with temporary_dir() as directory_for_journal: size = get_vhd_size(child) journal_file = os.path.join( directory_for_journal, 'vhd-util-resize-journal') resize_vhd(parent, size, journal_file) coalesce_vhd(child) return vhd_chain[-1] def discover_vhd_chain(directory): counter = 0 chain = [] while True: fpath = os.path.join(directory, '%d.vhd' % counter) if os.path.exists(fpath): chain.append(fpath) else: break counter += 1 return chain def replace_xenserver_image_with_coalesced_vhd(image_file): with temporary_dir() as tempdir: extract_targz(image_file, tempdir) chain = discover_vhd_chain(tempdir) fix_vhd_chain(chain) coalesced = coalesce_chain(chain) fileutils.delete_if_exists(image_file) os.rename(coalesced, image_file) class TemporaryImages(object): """Manage temporarily downloaded images to avoid downloading it twice. In the 'with TemporaryImages.fetch(image_service, ctx, image_id) as tmp' clause, 'tmp' can be used as the downloaded image path. In addition, image_utils.fetch() will use the pre-fetched image by the TemporaryImages. This is useful to inspect image contents before conversion. """ def __init__(self, image_service): self.temporary_images = {} self.image_service = image_service image_service.temp_images = self @staticmethod def for_image_service(image_service): instance = image_service.temp_images if instance: return instance return TemporaryImages(image_service) @classmethod @contextlib.contextmanager def fetch(cls, image_service, context, image_id, suffix=''): tmp_images = cls.for_image_service(image_service).temporary_images with temporary_file(suffix=suffix) as tmp: fetch_verify_image(context, image_service, image_id, tmp) user = context.user_id if not tmp_images.get(user): tmp_images[user] = {} tmp_images[user][image_id] = tmp LOG.debug("Temporary image %(id)s is fetched for user %(user)s.", {'id': image_id, 'user': user}) yield tmp del tmp_images[user][image_id] LOG.debug("Temporary image %(id)s for user %(user)s is deleted.", {'id': image_id, 'user': user}) def get(self, context, image_id): user = context.user_id if not self.temporary_images.get(user): return None return self.temporary_images[user].get(image_id)