Coverage for nova/virt/images.py: 81%

2# Administrator of the National Aeronautics and Space Administration.

6# Licensed under the Apache License, Version 2.0 (the "License"); you may

7# not use this file except in compliance with the License. You may obtain

8# a copy of the License at

10# http://www.apache.org/licenses/LICENSE-2.0

11#

12# Unless required by applicable law or agreed to in writing, software

13# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

14# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the

15# License for the specific language governing permissions and limitations

16# under the License.

18"""

19Handling of VM disk images.

20"""

22import os

24from oslo_concurrency import processutils

25from oslo_log import log as logging

26from oslo_utils import fileutils

27from oslo_utils import imageutils

28from oslo_utils.imageutils import format_inspector

30from nova.compute import utils as compute_utils

31import nova.conf

32from nova import exception

33from nova.i18n import _

34from nova.image import glance

35import nova.privsep.qemu

37LOG = logging.getLogger(__name__)

39CONF = nova.conf.CONF

40IMAGE_API = glance.API()

43def qemu_img_info(path, format=None):

44 """Return an object containing the parsed output from qemu-img info."""

45 if not os.path.exists(path) and not path.startswith('rbd:'):

46 raise exception.DiskNotFound(location=path)

48 info = nova.privsep.qemu.unprivileged_qemu_img_info(path, format=format)

49 return imageutils.QemuImgInfo(info, format='json')

52def privileged_qemu_img_info(path, format=None, output_format='json'):

53 """Return an object containing the parsed output from qemu-img info."""

54 if not os.path.exists(path) and not path.startswith('rbd:'):

55 raise exception.DiskNotFound(location=path)

57 info = nova.privsep.qemu.privileged_qemu_img_info(path, format=format)

58 return imageutils.QemuImgInfo(info, format='json')

61def convert_image(source, dest, in_format, out_format, run_as_root=False,

62 compress=False, src_encryption=None, dest_encryption=None):

63 """Convert image to other format."""

64 if in_format is None: 64 ↛ 65line 64 didn't jump to line 65 because the condition on line 64 was never true

65 raise RuntimeError("convert_image without input format is a security"

66 " risk")

67 _convert_image(source, dest, in_format, out_format, run_as_root,

68 compress=compress, src_encryption=src_encryption,

69 dest_encryption=dest_encryption)

72def convert_image_unsafe(source, dest, out_format, run_as_root=False):

73 """Convert image to other format, doing unsafe automatic input format

74 detection. Do not call this function.

75 """

77 # NOTE: there is only 1 caller of this function:

78 # imagebackend.Lvm.create_image. It is not easy to fix that without a

79 # larger refactor, so for the moment it has been manually audited and

80 # allowed to continue. Remove this function when Lvm.create_image has

81 # been fixed.

82 _convert_image(source, dest, None, out_format, run_as_root)

85def _convert_image(source, dest, in_format, out_format, run_as_root,

86 compress=False, src_encryption=None, dest_encryption=None):

87 try:

88 with compute_utils.disk_ops_semaphore:

89 if not run_as_root:

90 nova.privsep.qemu.unprivileged_convert_image(

91 source, dest, in_format, out_format, CONF.instances_path,

92 compress, src_encryption=src_encryption,

93 dest_encryption=dest_encryption)

94 else:

95 nova.privsep.qemu.convert_image(

96 source, dest, in_format, out_format, CONF.instances_path,

97 compress, src_encryption=src_encryption,

98 dest_encryption=dest_encryption)

100 except processutils.ProcessExecutionError as exp:

101 msg = (_("Unable to convert image to %(format)s: %(exp)s") %

102 {'format': out_format, 'exp': exp})

103 raise exception.ImageUnacceptable(image_id=source, reason=msg)

104

105

106def fetch(context, image_href, path, trusted_certs=None):

107 with fileutils.remove_path_on_error(path):

108 with compute_utils.disk_ops_semaphore:

109 IMAGE_API.download(context, image_href, dest_path=path,

110 trusted_certs=trusted_certs)

111

112

113def get_info(context, image_href):

114 return IMAGE_API.get(context, image_href)

115

116

117def check_vmdk_image(image_id, data):

118 # Check some rules about VMDK files. Specifically we want to make

119 # sure that the "create-type" of the image is one that we allow.

120 # Some types of VMDK files can reference files outside the disk

121 # image and we do not want to allow those for obvious reasons.

122

123 types = CONF.compute.vmdk_allowed_types

124

125 if not len(types):

126 LOG.warning('Refusing to allow VMDK image as vmdk_allowed_'

127 'types is empty')

128 msg = _('Invalid VMDK create-type specified')

129 raise exception.ImageUnacceptable(image_id=image_id, reason=msg)

130

131 try:

132 create_type = data.format_specific['data']['create-type']

133 except KeyError:

134 msg = _('Unable to determine VMDK create-type')

135 raise exception.ImageUnacceptable(image_id=image_id, reason=msg)

136

137 if create_type not in CONF.compute.vmdk_allowed_types:

138 LOG.warning('Refusing to process VMDK file with create-type of %r '

139 'which is not in allowed set of: %s', create_type,

140 ','.join(CONF.compute.vmdk_allowed_types))

141 msg = _('Invalid VMDK create-type specified')

142 raise exception.ImageUnacceptable(image_id=image_id, reason=msg)

143

144

145def get_image_format(path):

146 with open(path, 'rb') as f:

147 wrapper = format_inspector.InspectWrapper(f)

148 try:

149 while f.peek(): 149 ↛ 150line 149 didn't jump to line 150 because the condition on line 149 was never true

150 wrapper.read(4096)

151 if wrapper.formats:

152 break

153 finally:

154 wrapper.close()

155

156 try:

157 return wrapper.format

158 except format_inspector.ImageFormatError:

159 format_names = set(str(x) for x in wrapper.formats)

160 if format_names == {'iso', 'gpt'}:

161 # If iso+gpt, we choose the iso because bootable-as-block ISOs

162 # can legitimately have a GPT bootloader in front.

163 LOG.debug('Detected %s as ISO+GPT, allowing as ISO', path)

164 return [x for x in wrapper.formats if str(x) == 'iso'][0]

165 # Any other case of multiple formats is an error

166 raise

167

168

169def do_image_deep_inspection(img, image_href, path):

170 ami_formats = ('ami', 'aki', 'ari')

171 disk_format = img['disk_format']

172 try:

173 # NOTE(danms): Use our own cautious inspector module to make sure

174 # the image file passes safety checks.

175 # See https://bugs.launchpad.net/nova/+bug/2059809 for details.

176

177 # Make sure we have a format inspector for the claimed format, else

178 # it is something we do not support and must reject. AMI is excluded.

179 if (disk_format not in ami_formats and

180 not format_inspector.get_inspector(disk_format)):

181 raise exception.ImageUnacceptable(

182 image_id=image_href,

183 reason=_('Image not in a supported format'))

184

185 inspector = get_image_format(path)

186 inspector.safety_check()

187

188 # Images detected as gpt but registered as raw are legacy "whole disk"

189 # formats, which we continue to allow for now.

190 # AMI formats can be other things, so don't obsess over this

191 # requirement for them. Otherwise, make sure our detection agrees

192 # with glance.

193 if disk_format == 'raw' and str(inspector) == 'gpt': 193 ↛ 194line 193 didn't jump to line 194 because the condition on line 193 was never true

194 LOG.debug('Image %s registered as raw, but detected as gpt',

195 image_href)

196 elif disk_format not in ami_formats and str(inspector) != disk_format:

197 # If we detected the image as something other than glance claimed,

198 # we abort.

199 LOG.warning('Image %s expected to be %s but detected as %s',

200 image_href, disk_format, str(inspector))

201 raise exception.ImageUnacceptable(

202 image_id=image_href,

203 reason=_('Image content does not match disk_format'))

204 except format_inspector.SafetyCheckFailed as e:

205 LOG.error('Image %s failed safety check: %s', image_href, e)

206 raise exception.ImageUnacceptable(

207 image_id=image_href,

208 reason=(_('Image does not pass safety check')))

209 except format_inspector.ImageFormatError:

210 # If the inspector we chose based on the image's metadata does not

211 # think the image is the proper format, we refuse to use it.

212 raise exception.ImageUnacceptable(

213 image_id=image_href,

214 reason=_('Image content does not match disk_format'))

215 except Exception:

216 raise exception.ImageUnacceptable(

217 image_id=image_href,

218 reason=_('Image not in a supported format'))

219 if disk_format in ('iso',) + ami_formats:

220 # ISO or AMI image passed safety check; qemu will treat this as raw

221 # from here so return the expected formats it will find.

222 disk_format = 'raw'

223 return disk_format

224

225

226def fetch_to_raw(context, image_href, path, trusted_certs=None):

227 path_tmp = "%s.part" % path

228 fetch(context, image_href, path_tmp, trusted_certs)

229

230 with fileutils.remove_path_on_error(path_tmp):

231 if not CONF.workarounds.disable_deep_image_inspection:

232 # If we're doing deep inspection, we take the determined format

233 # from it.

234 img = IMAGE_API.get(context, image_href)

235 force_format = do_image_deep_inspection(img, image_href, path_tmp)

236 else:

237 force_format = None

238

239 # Only run qemu-img after we have done deep inspection (if enabled).

240 # If it was not enabled, we will let it detect the format.

241 data = qemu_img_info(path_tmp)

242 fmt = data.file_format

243 if fmt is None: 243 ↛ 244line 243 didn't jump to line 244 because the condition on line 243 was never true

244 raise exception.ImageUnacceptable(

245 reason=_("'qemu-img info' parsing failed."),

246 image_id=image_href)

247 elif force_format is not None and fmt != force_format:

248 # Format inspector and qemu-img must agree on the format, else

249 # we reject. This will catch VMDK some variants that we don't

250 # explicitly support because qemu will identify them as such

251 # and we will not.

252 LOG.warning('Image %s detected by qemu as %s but we expected %s',

253 image_href, fmt, force_format)

254 raise exception.ImageUnacceptable(

255 image_id=image_href,

256 reason=_('Image content does not match disk_format'))

257

258 backing_file = data.backing_file

259 if backing_file is not None:

260 raise exception.ImageUnacceptable(image_id=image_href,

261 reason=(_("fmt=%(fmt)s backed by: %(backing_file)s") %

262 {'fmt': fmt, 'backing_file': backing_file}))

263

264 try:

265 data_file = data.format_specific['data']['data-file']

266 except (KeyError, TypeError, AttributeError):

267 data_file = None

268 if data_file is not None:

269 raise exception.ImageUnacceptable(image_id=image_href,

270 reason=(_("fmt=%(fmt)s has data-file: %(data_file)s") %

271 {'fmt': fmt, 'data_file': data_file}))

272

273 if fmt == 'vmdk':

274 check_vmdk_image(image_href, data)

275

276 if fmt != "raw" and CONF.force_raw_images:

277 staged = "%s.converted" % path

278 LOG.debug("%s was %s, converting to raw", image_href, fmt)

279 with fileutils.remove_path_on_error(staged):

280 try:

281 convert_image(path_tmp, staged, fmt, 'raw')

282 except exception.ImageUnacceptable as exp:

283 # re-raise to include image_href

284 raise exception.ImageUnacceptable(image_id=image_href,

285 reason=_("Unable to convert image to raw: %(exp)s")

286 % {'exp': exp})

287

288 os.unlink(path_tmp)

289

290 data = qemu_img_info(staged)

291 if data.file_format != "raw": 291 ↛ 292line 291 didn't jump to line 292 because the condition on line 291 was never true

292 raise exception.ImageUnacceptable(image_id=image_href,

293 reason=_("Converted to raw, but format is now %s") %

294 data.file_format)

295

296 os.rename(staged, path)

297 else:

298 os.rename(path_tmp, path)