Stein Series Release Notes¶
This version of python-glanceclient adds Python 3.6 classifier and gating on Python 3.7 environment.
For parity with the old
checksumfield, this release adds the ability for CLI users to filter the image list based upon a particular multihash value using the
--hash <HASH_VALUE>option. Issue the command:
glance help image-list
for more information.
Support for embedding validation data (checksum and multihash) when adding a location to an image. Requires the Stein release server-side.
glance.images.add_location()method now accepts an optional argument
validation_data, in the form of a dictionary containing
location-addcommand now accepts optional arguments
This release adds verification of image data downloads using the Glance “multihash” feature introduced in the OpenStack Rocky release. When the
os_hash_valueis populated on an image, the glanceclient will verify this value by computing the hexdigest of the downloaded data using the algorithm specified by the image’s
Because the secure hash algorithm specified is determined by the cloud provider, it is possible that the
os_hash_algomay identify an algorithm not available in the version of the Python
hashliblibrary used by the client. In such a case the download will fail due to an unsupported hash type. In the event this occurs, a new option,
--allow-md5-fallback, is introduced to the
image-downloadcommand. When present, this option will allow the glanceclient to use the legacy MD5 checksum to verify the downloaded data if the secure hash algorithm specified by the
os_hash_algoimage property is not supported.
Note that the fallback is not used in the case where the algorithm is supported but the hexdigest of the downloaded data does not match the
os_hash_value. In that case the download fails regardless of whether the option is present or not.
Whether using the
--allow-md5-fallbackoption is a good idea depends upon the user’s expectations for the verification. MD5 is an insecure hashing algorithm, so if you are interested in making sure that the downloaded image data has not been replaced by a datastream carefully crafted to have the same MD5 checksum, then you should not use the fallback. If, however, you are using Glance in a trusted environment and your interest is simply to verify that no bits have flipped during the data transfer, the MD5 fallback is sufficient for that purpose. That being said, it is our recommendation that the multihash should be used whenever possible.
This release of the glanceclient uses the Glance “multihash” feature, introduced in Rocky, to use a secure hashing algorithm to verify the integrity of downloaded data. Legacy images without the “multihash” image properties (
os_hash_value) are verified using the MD5