test_volume_from_snapshot does not work with Dell PowerFlex driver

[Sam Wan]

PowerFlex/VxFlex OS requires volumes to be sized in multiples of 8GB.
Even if 1GB is given when creating a volume, a 8GB volume will be created if powerflex_round_volume_capacity = True, otherwise the volume creation will fail.
[https://docs.openstack.org/cinder/latest/configuration/block-storage/drivers/dell-emc-powerflex-driver.html]

The test case test_volume_from_snapshot has extra_size hardcoded to 1 and it expects the returned size increased by 1GB. However this does not work with PowerFlex driver due to the above reason, so error occurs.
==================================
{0} tempest.api.volume.test_volumes_snapshots.VolumesSnapshotTestJSON.test_volume_from_snapshot [4.715851s] ... FAILED

Captured traceback:
~~~~~~~~~~~~~~~~~~~
    Traceback (most recent call last):

      File "/opt/stack/new/tempest/tempest/api/volume/test_volumes_snapshots.py", line 170, in test_volume_from_snapshot
    self._create_volume_from_snapshot(extra_size=1)

      File "/opt/stack/new/tempest/tempest/api/volume/test_volumes_snapshots.py", line 165, in _create_volume_from_snapshot
    self.assertEqual(volume['size'], size)

      File "/usr/local/lib/python3.8/dist-packages/testtools/testcase.py", line 393, in assertEqual
    self.assertThat(observed, matcher, message)

      File "/usr/local/lib/python3.8/dist-packages/testtools/testcase.py", line 480, in assertThat
    raise mismatch_error

    testtools.matchers._impl.MismatchError: 16 != 9
===================================

extra_size should not be hardcoded to 1, instead it should be set to CONF.volume.volume_size, for PowerFlex, it's 8.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/tempest/+/816779

[Martin Kopec (mkopec)]

Let's use CONF.volume.volume_size_extend option in the test, the opt was introduced by the following commit - seems like we forgot to edit this test back then:

https://opendev.org/openstack/tempest/commit/37c4bd3023110f2a00e55439e2086d393b44a974

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/tempest/+/816779
Committed: https://opendev.org/openstack/tempest/commit/0bacf984313a337cdfce49d61949e585aa134e19
Submitter: "Zuul (22348)"
Branch: master

commit 0bacf984313a337cdfce49d61949e585aa134e19
Author: Sam Wan <email address hidden>
Date: Fri Nov 5 10:07:42 2021 +0800

    Change extra_size from hardcoded 1 to CONF.volume.volume_size_extend

    test_volume_from_snapshot has extra_size hardcoded to 1 and it expects
    the returned size increased by 1GB. This does not work with PowerFlex
    cinder driver because PowerFlex/VxFlex OS requires volumes to be sized
    in multiples of 8GB. Even if 1GB is given, 8GB will be actually used
    when powerflex_round_volume_capacity = True.

    Closes-Bug: #1949927
    Change-Id: I04c3d6145fbc201355d38a7a058a37791227f733

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tempest 30.0.0 release.