Missing description of subcommad 'list-extensions' in cinder help information.

[zhangdaolong]

Now the current cinderclient version default use v3 interface. And the do_list_extensions of V3 inherited V2.
The do_list_extensions of V2 does not have __doc__.For the cli-reference, there is a specific docs tool used
to auto-generate the cli-reference files.The docs tool find the function __doc__ that starts with 'do_',as The do_list_extensions's __doc__ is none,so the subcommand 'list-extensions' no desc.

python-cinderclient/cinderclient/shell.py
---------------------------------
def _find_actions(self, subparsers, actions_module, version,
                      do_help, input_args):
        for attr in (a for a in dir(actions_module) if a.startswith('do_')):
            # I prefer to be hyphen-separated instead of underscores.
            command = attr[3:].replace('_', '-')
            callback = getattr(actions_module, attr)
            desc = callback.__doc__ or ''
            .......

The OpenStack contributor guide has instructions. The guide has a chapter on how to use the docs
tools - https://docs.openstack.org/contributor-guide/doc-tools.html
Specifically, the chapter on the command line reference explains how the tool works - https://docs.openstack.org/contributor-guide/doc-tools/cli-reference.html

cinder help
--------------------------
........
    unmanage Stop managing a volume.
    upload-to-image Uploads volume to Image Service as an image.
    version-list List all API versions. (Supported by API versions 3.0
                        - 3.latest)
    bash-completion Prints arguments for bash_completion.
    help Shows help about this program or one of its
                        subcommands.
    list-extensions ---->No description information
........
-----------------------------
the subcommand 'list-extensions' does not have description,
as the cinder Command-Line Interface of files are automatically[1] generated
.Resulting in the same lack of information in the document

https://docs.openstack.org/cli-reference/cinder.html
-----------------------------
........

version-list
    List all API versions. (Supported by API versions 3.0 - 3.latest) [hint: use '--os-volume-api-version' flag to show help message for proper version]
bash-completion
    Prints arguments for bash_completion.
help
    Shows help about this program or one of its subcommands.

list-extensions ----->No description information
---------------------------
Generate Command-Line Interface Reference
[1]:https://docs.openstack.org/contributor-guide/doc-tools/cli-reference.html

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/448546

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/448546
Committed: https://git.openstack.org/cgit/openstack/python-cinderclient/commit/?id=b2f930348867e7689570c03ef7d6258a2836e56e
Submitter: Jenkins
Branch: master

commit b2f930348867e7689570c03ef7d6258a2836e56e
Author: zhangdaolong <email address hidden>
Date: Wed Mar 22 19:45:38 2017 +0800

    Add description for function do_list_extensions in cinderclient

    Now the current cinderclient version default use v3 interface.
    And the do_list_extensions of V3 inherited V2. The do_list_extensions
    of V2 does not have __doc__.For the cli-reference, there is a specific
    docs tool used to auto-generate the cli-reference files.The docs tool
    find the function __doc__ that starts with 'do_',as The
    do_list_extensions's __doc__ is none,so the subcommand 'list-extensions'
    no desc.

    python-cinderclient/cinderclient/shell.py
    ---------------------------------
    def _find_actions(self, subparsers, actions_module, version,
                          do_help, input_args):
            for attr in (a for a in dir(actions_module) if
    a.startswith('do_')):
                # I prefer to be hyphen-separated instead of underscores.
                command = attr[3:].replace('_', '-')
                callback = getattr(actions_module, attr)
                desc = callback.__doc__ or ''
                .......

    The OpenStack contributor guide has instructions. The guide has a
    chapter on how to use the duto-generate docs tools
    - https://docs.openstack.org/contributor-guide/doc-tools.html
    Specifically, the chapter on the command line reference explains
    how the tool works -
    https://docs.openstack.org/contributor-guide/doc-tools/cli-reference.html

    Change-Id: I5484d1e25b4ec11182b27c80fc43e816b1a12736
    Closes-Bug: #1674934

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-cinderclient 3.0.0 release.