Cinder shows a raw python error when using --os-volume-api-version incorrectly

[Sofia Enriquez]

Description of problem:
In general, cinder shows a help message when a user types a wrong command. However, when using microversion shows a raw python error prompts.

How reproducible:

cinder --version
> 6.0.0

cinder --os-volume-api-version 3.40
> ERROR: 'Namespace' object has no attribute 'func'

Actual results:
ERROR: 'Namespace' object has no attribute 'func'

Expected results:
It must be something about adding the option that messes things up.

[Sean McGinnis (sean-mcginnis)]

Some more info:

cinder --debug --os-volume-api-version 3.40
DEBUG (shell:1026) 'Namespace' object has no attribute 'func'
Traceback (most recent call last):
  File "/home/smcginnis/src/openstack/python-cinderclient/cinderclient/shell.py", line 1018, in main
    OpenStackCinderShell().main(sys.argv[1:])
  File "/home/smcginnis/src/openstack/python-cinderclient/cinderclient/shell.py", line 609, in main
    if args.func == self.do_help:
AttributeError: 'Namespace' object has no attribute 'func'
DEBUG:cinderclient.shell:'Namespace' object has no attribute 'func'
Traceback (most recent call last):
  File "/home/smcginnis/src/openstack/python-cinderclient/cinderclient/shell.py", line 1018, in main
    OpenStackCinderShell().main(sys.argv[1:])
  File "/home/smcginnis/src/openstack/python-cinderclient/cinderclient/shell.py", line 609, in main
    if args.func == self.do_help:
AttributeError: 'Namespace' object has no attribute 'func'
ERROR: 'Namespace' object has no attribute 'func'

[Sean McGinnis (sean-mcginnis)]

Works fine for me if I actually give it a command, so appears to be just when needing to print the help output.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/759440

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/759440
Committed: https://git.openstack.org/cgit/openstack/python-cinderclient/commit/?id=d92f15a09e59942bb60b7ef3a81c1e21dc16b578
Submitter: Zuul
Branch: master

commit d92f15a09e59942bb60b7ef3a81c1e21dc16b578
Author: Eduardo Santos <email address hidden>
Date: Fri Oct 23 14:17:23 2020 +0000

    Fix undesirable raw Python error

    Using the cinderclient without a subcommand while
    passing an optional argument triggers the raw Python
    error `ERROR: 'Namespace' object has no attribute
    'func'`. This bug can be reproduced by issuing the
    command `cinder --os-volume-api-version 3.40`.
    Added a default value to `func` and an empty value to
    `command` as placeholders so that a help message is
    shown instead of the Python error.

    Change-Id: Idb51e8635b97f0da2976f3268d5e19100ec77203
    Closes-Bug: #1867061

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-cinderclient 7.3.0 release.