def verify_base_size(base, size, base_size=0):
"""Check that the base image is not larger than size.
Since images can't be generally shrunk, enforce this
constraint taking account of virtual image size.
"""
# Note(pbrady): The size and min_disk parameters of a glance
# image are checked against the instance size before the image
# is even downloaded from glance, but currently min_disk is
# adjustable and doesn't currently account for virtual disk size,
# so we need this extra check here.
# NOTE(cfb): Having a flavor that sets the root size to 0 and having
# nova effectively ignore that size and use the size of the
# image is considered a feature at this time, not a bug.
if size is None:
return
if size and not base_size:
base_size = disk.get_disk_size(base)
if size < base_size:
msg = _('%(base)s virtual size %(base_size)s '
'larger than flavor root disk size %(size)s')
LOG.error(msg % {
'base': base,
'base_size': base_size,
'size': size
})
raise exception.InstanceTypeDiskTooSmall()
def create_image(self, prepare_template, base, size, *args, **kwargs):
@utils.synchronized(base, external=True, lock_path=self.lock_path)
def copy_qcow2_image(base, target, size):
# TODO(pbrady): Consider copying the cow image here
# with preallocation=metadata set for performance reasons.
# This would be keyed on a 'preallocate_images' setting.
libvirt_utils.create_cow_image(base, target)
if size:
disk.extend(target, size)
# Download the unmodified base image unless we already have a copy.
if not os.path.exists(base):
prepare_template(target=base, *args, **kwargs)
legacy_backing_size = None
legacy_base = base
# Determine whether an existing qcow2 disk uses a legacy backing by
# actually looking at the image itself and parsing the output of the
# backing file it expects to be using.
if os.path.exists(self.path):
backing_path = libvirt_utils.get_disk_backing_file(self.path)
if backing_path is not None:
backing_file = os.path.basename(backing_path)
backing_parts = backing_file.rpartition('_')
if backing_file != backing_parts[-1] and \
backing_parts[-1].isdigit():
legacy_backing_size = int(backing_parts[-1])
legacy_base += '_%d' % legacy_backing_size
legacy_backing_size *= 1024 * 1024 * 1024
# Create the legacy backing file if necessary.
if legacy_backing_size:
if not os.path.exists(legacy_base):
with fileutils.remove_path_on_error(legacy_base):
libvirt_utils.copy_image(base, legacy_base)
disk.extend(legacy_base, legacy_backing_size)
# NOTE(cfb): Having a flavor that sets the root size to 0 and having
# nova effectively ignore that size and use the size of the
# image is considered a feature at this time, not a bug.
disk_size = disk.get_disk_size(base)
if size and size < disk_size:
msg = _('%(base)s virtual size %(disk_size)s'
'larger than flavor root disk size %(size)s')
LOG.error(msg % {
'base': base,
'disk_size': disk_size,
'size': size
})
raise exception.InstanceTypeDiskTooSmall()
if not os.path.exists(self.path):
with fileutils.remove_path_on_error(self.path):
copy_qcow2_image(base, self.path, size)
def create_image(self, prepare_template, base, size, *args, **kwargs):
@utils.synchronized(base, external=True, lock_path=self.lock_path)
def copy_qcow2_image(base, target, size):
# TODO(pbrady): Consider copying the cow image here
# with preallocation=metadata set for performance reasons.
# This would be keyed on a 'preallocate_images' setting.
libvirt_utils.create_cow_image(base, target)
if size:
disk.extend(target, size)
if not os.path.exists(base):
prepare_template(target=base, *args, **kwargs)
# NOTE(cfb): Having a flavor that sets the root size to 0 and having
# nova effectively ignore that size and use the size of the
# image is considered a feature at this time, not a bug.
if size and size < disk.get_disk_size(base):
LOG.error('%s virtual size larger than flavor root disk size %s' %
(base, size))
raise exception.InstanceTypeDiskTooSmall()
if not os.path.exists(self.path):
with utils.remove_path_on_error(self.path):
copy_qcow2_image(base, self.path, size)
def fetch_to_raw(context, image_href, path, user_id, project_id, max_size=0):
path_tmp = "%s.part" % path
fetch(context,
image_href,
path_tmp,
user_id,
project_id,
max_size=max_size)
with fileutils.remove_path_on_error(path_tmp):
data = qemu_img_info(path_tmp)
fmt = data.file_format
if fmt is None:
raise exception.ImageUnacceptable(
reason=_("'qemu-img info' parsing failed."),
image_id=image_href)
backing_file = data.backing_file
if backing_file is not None:
raise exception.ImageUnacceptable(
image_id=image_href,
reason=(_("fmt=%(fmt)s backed by: %(backing_file)s") % {
'fmt': fmt,
'backing_file': backing_file
}))
# We can't generally shrink incoming images, so disallow
# images > size of the flavor we're booting. Checking here avoids
# an immediate DoS where we convert large qcow images to raw
# (which may compress well but not be sparse).
# TODO(p-draigbrady): loop through all flavor sizes, so that
# we might continue here and not discard the download.
# If we did that we'd have to do the higher level size checks
# irrespective of whether the base image was prepared or not.
disk_size = data.virtual_size
if max_size and max_size < disk_size:
msg = _('%(base)s virtual size %(disk_size)s '
'larger than flavor root disk size %(size)s')
LOG.error(msg % {
'base': path,
'disk_size': disk_size,
'size': max_size
})
raise exception.InstanceTypeDiskTooSmall()
if fmt != "raw" and CONF.force_raw_images:
staged = "%s.converted" % path
LOG.debug("%s was %s, converting to raw" % (image_href, fmt))
with fileutils.remove_path_on_error(staged):
convert_image(path_tmp, staged, 'raw')
os.unlink(path_tmp)
data = qemu_img_info(staged)
if data.file_format != "raw":
raise exception.ImageUnacceptable(
image_id=image_href,
reason=_("Converted to raw, but format is now %s") %
data.file_format)
os.rename(staged, path)
else:
os.rename(path_tmp, path)