api-ref: block_device_mapping_v2.volume_size does not mention when it's required

[Matt Riedemann]

As seen in this failed tempest test:

http://logs.openstack.org/50/332050/18/check/tempest-full/f146d24/controller/logs/screen-n-api.txt.gz#_Mar_01_21_57_53_623712

Mar 01 21:57:53.536297 ubuntu-bionic-rax-dfw-0003242602 <email address hidden>[3071]: DEBUG nova.compute.api [None req-3ba6b743-aa11-468f-a524-dc19ceb16b4e tempest-DetachAttachBootVolumeShelveTestJSON-1339257189 tempest-DetachAttachBootVolumeShelveTestJSON-1339257189] [instance: ba7510aa-3f20-4849-a5e4-5f582a888d6e] block_device_mapping [BlockDeviceMapping(attachment_id=<?>,boot_index=0,connection_info=None,created_at=<?>,delete_on_termination=False,deleted=<?>,deleted_at=<?>,destination_type='volume',device_name=None,device_type=None,disk_bus=None,guest_format=None,id=<?>,image_id='83216c87-cd74-451f-b814-7a0baa0a51c7',instance=<?>,instance_uuid=<?>,no_device=False,snapshot_id=None,source_type='image',tag='root',updated_at=<?>,uuid=<?>,volume_id=None,volume_size=None,volume_type=None)] {{(pid=3072) _bdm_validate_set_size_and_instance /opt/stack/nova/nova/compute/api.py:1347}}
Mar 01 21:57:53.623712 ubuntu-bionic-rax-dfw-0003242602 <email address hidden>[3071]: INFO nova.api.openstack.wsgi [None req-3ba6b743-aa11-468f-a524-dc19ceb16b4e tempest-DetachAttachBootVolumeShelveTestJSON-1339257189 tempest-DetachAttachBootVolumeShelveTestJSON-1339257189] HTTP exception thrown: Images with destination_type 'volume' need to have a non-zero size specified

Trying to boot from volume with source_type='image' and destination_type='volume' requires the volume_size to be specified:

https://github.com/openstack/nova/blob/5a09c81af3b438ecbcf27fa653095ff55abb3ed4/nova/compute/api.py#L1461

But that's not mentioned in the API reference which just says (for volume_size):

"The size of the volume (in GiB). This is integer value from range 1 to 2147483647 which can be requested as integer and string."

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/641255

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/641255
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=f87bf4c6b9b9916bdb6963024e50e3346b7c34ea
Submitter: Zuul
Branch: master

commit f87bf4c6b9b9916bdb6963024e50e3346b7c34ea
Author: Takashi NATSUME <email address hidden>
Date: Wed Mar 6 15:54:23 2019 +0900

    api-ref: Add description for BDM volume_size

    Add description of cases that 'block_device_mapping_v2.volume_size`
    is required in the "Create Server" (POST /servers) API.

    Change-Id: I36f28ca756b908b5fc591cc87f5786a3e217285e
    Closes-Bug: #1818310

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 19.0.0.0rc1 release candidate.