cinder.image.image_utils module¶

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

class TemporaryImages(image_service: GlanceImageService)¶

Bases: 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.

classmethod fetch(image_service: GlanceImageService, context: RequestContext, image_id: str, suffix: Optional[str] = '') → Generator[str, None, None]¶

static for_image_service(image_service: GlanceImageService) → TemporaryImages¶

get(context: RequestContext, image_id: str)¶

check_available_space(dest: str, image_size: int, image_id: str) → None¶

check_image_conversion_disable(disk_format, volume_format, image_id, upload=False)¶

check_image_format(source: str, src_format: Optional[str] = None, image_id: Optional[str] = None, data: Optional[QemuImgInfo] = None, run_as_root: bool = True) → None¶

Do some image format checks.

Verifies that the src_format matches what qemu-img thinks the image format is, and does some vmdk subformat checks. See Bug #1996188.

• Does not check for a qcow2 backing file.

• Will make a call out to qemu_img if data is None.

Parameters:

• source – filename of the image to check

• src_format – source image format recognized by qemu_img, or None

• image_id – the image ID if this is a Glance image, or None

• data – a imageutils.QemuImgInfo object from this image, or None

• run_as_root – when ‘data’ is None, call ‘qemu-img info’ as root

Raises:

• ImageUnacceptable – when the image fails some format checks

• ProcessExecutionError – if ‘qemu-img info’ fails

check_qcow2_image(image_id: str, data: QemuImgInfo) → None¶

Check some rules about qcow2 images.

Does not check for a backing_file, because cinder has some legitimate use cases for qcow2 backing files.

Makes sure the image:

• does not have a data_file

Parameters:

• image_id – the image id

• data – an imageutils.QemuImgInfo object

Raises:

ImageUnacceptable – when the image fails the check

check_qemu_img_version(minimum_version: str) → None¶

check_virtual_size(virtual_size: float, volume_size: int, image_id: str) → int¶

check_vmdk_image(image_id: str, data: QemuImgInfo) → None¶

Check some rules about VMDK images.

Make sure the VMDK subformat (the “createType” in vmware docs) is one that we allow as determined by the ‘vmdk_allowed_types’ configuration option. The default set includes only types that do not reference files outside the VMDK file, which can otherwise be used in exploits to expose host information.

Parameters:

• image_id – the image id

• data – an imageutils.QemuImgInfo object

Raises:

ImageUnacceptable – when the VMDK createType is not in the allowed list

cleanup_temporary_file(backend_name: str) → None¶

coalesce_chain(vhd_chain: list[str]) → str¶

coalesce_vhd(vhd_path: str) → None¶

convert_image(source: str, dest: str, out_format: str, out_subformat: Optional[str] = None, src_format: Optional[str] = None, run_as_root: bool = True, throttle=None, cipher_spec: Optional[dict] = None, passphrase_file: Optional[str] = None, compress: bool = False, src_passphrase_file: Optional[str] = None, image_id: Optional[str] = None, data: Optional[QemuImgInfo] = None) → None¶

Convert image to other format.

NOTE: If the qemu-img convert command fails and this function raises an exception, a non-empty dest file may be left in the filesystem. It is the responsibility of the caller to decide what to do with this file.

Parameters:

• source – source filename

• dest – destination filename

• out_format – output image format of qemu-img

• out_subformat – output image subformat

• src_format – source image format (use image_utils.fixup_disk_format() to translate from a Glance format to one recognizable by qemu_img)

• run_as_root – run qemu-img as root

• throttle – a cinder.throttling.Throttle object, or None

• cipher_spec – encryption details

• passphrase_file – filename containing luks passphrase

• compress – compress w/ qemu-img when possible (best effort)

• src_passphrase_file – filename containing source volume’s luks passphrase

• image_id – the image ID if this is a Glance image, or None

• data – a imageutils.QemuImgInfo object from this image, or None

Raises:

• ImageUnacceptable – when the image fails some format checks

• ProcessExecutionError – when something goes wrong during conversion

create_temporary_file(*args: str, **kwargs: str) → str¶

decode_cipher(cipher_spec: str, key_size: int) → dict[str, str]¶

Decode a dm-crypt style cipher specification string

The assumed format being cipher-chainmode-ivmode, similar to that documented under linux/Documentation/admin-guide/device-mapper/dm-crypt.txt in the kernel source tree. Cinder does not support the [:keycount] or [:ivopts] options.

discover_vhd_chain(directory: str) → list[str]¶

extract_targz(archive_name: str, target: str) → None¶

fetch(context: RequestContext, image_service: GlanceImageService, image_id: str, path: str, _user_id, _project_id) → None¶

fetch_to_raw(context: RequestContext, image_service: GlanceImageService, image_id: str, dest: str, blocksize: int, user_id: Optional[str] = None, project_id: Optional[str] = None, size: Optional[int] = None, run_as_root: bool = True) → None¶

fetch_to_vhd(context: RequestContext, image_service: GlanceImageService, image_id: str, dest: str, blocksize: int, volume_subformat: Optional[str] = None, user_id: Optional[str] = None, project_id: Optional[str] = None, run_as_root: bool = True) → None¶

fetch_to_volume_format(context: RequestContext, image_service: GlanceImageService, image_id: str, dest: str, volume_format: str, blocksize: int, volume_subformat: Optional[str] = None, user_id: Optional[str] = None, project_id: Optional[str] = None, size: Optional[int] = None, run_as_root: bool = True) → None¶

fetch_verify_image(context: RequestContext, image_service: GlanceImageService, image_id: str, dest: str) → None¶

filter_out_reserved_namespaces_metadata(metadata: Optional[dict[str, str]]) → dict[str, str]¶

fix_vhd_chain(vhd_chain: list[str]) → None¶

fixup_disk_format(disk_format: str) → str¶

Return the format to be provided to qemu-img convert.

from_qemu_img_disk_format(disk_format: str) → str¶

Return the conventional format derived from qemu-img format.

get_qemu_data(image_id: str, has_meta: bool, disk_format_raw: bool, dest: str, run_as_root: bool, force_share: bool = False) → QemuImgInfo¶

get_qemu_img_version() → Optional[list[int]]¶

The qemu-img version will be cached until the process is restarted.

get_vhd_size(vhd_path: str) → int¶

is_xenserver_format(image_meta: dict) → bool¶

qemu_img_info(path: str, run_as_root: bool = True, force_share: bool = False, allow_qcow2_backing_file: bool = False) → QemuImgInfo¶

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

qemu_img_supports_force_share() → bool¶

replace_xenserver_image_with_coalesced_vhd(image_file: str) → None¶

resize_image(source: str, size: int, run_as_root: bool = False, file_format: Optional[str] = None) → None¶

Changes the virtual size of the image.

resize_vhd(vhd_path: str, size: int, journal: str) → None¶

set_vhd_parent(vhd_path: str, parentpath: str) → None¶

temporary_dir() → ContextManager[str]¶

temporary_file(*args: str, **kwargs) → Generator[str, None, None]¶

upload_volume(context: RequestContext, image_service: GlanceImageService, image_meta: dict, volume_path: str, volume_format: str = 'raw', run_as_root: bool = True, compress: bool = True, store_id: Optional[str] = None, base_image_ref: Optional[str] = None) → None¶

validate_stores_id(context: RequestContext, image_service_store_id: str) → None¶

verify_glance_image_signature(context: RequestContext, image_service: GlanceImageService, image_id: str, path: str) → bool¶