Calling glance with an invald value for --os-image-api-version causes unhelpful error message

[Louis Taylor]

Calling glance client with an invalid value for --os-image-api-version causes glance to output a message which does not clearly explain what went wrong:

    $ glance --os-image-api-version stupid-glance-version
    No module named vstupid-glance-version.shell

It would be nice if this error instead said that the version number was invalid, and maybe discovered the available versions.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/137108

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/137108
Committed: https://git.openstack.org/cgit/openstack/python-glanceclient/commit/?id=d5a0e657ed07a4a5ec503b80e71d1f136c79bb8e
Submitter: Jenkins
Branch: master

commit d5a0e657ed07a4a5ec503b80e71d1f136c79bb8e
Author: Louis Taylor <email address hidden>
Date: Tue Nov 25 15:33:57 2014 +0000

    Add useful error on invalid --os-image-api-version

    This adds a useful error message when a user enters an invalid value
    for --os-image-api-version. Previously, the shell directly attempted to
    import the module the user specified, and printed the error from the
    exception raised when that failed:

        $ glance --os-image-api-version stupid-glance-version
        No module named vstupid-glance-version.shell

    Glanceclient now catches this exception and prints something
    understandable for a user:

        $ glance --os-image-api-version stupid-glance-version
        "stupid-glance-version" is not a supported API version. Example values are "1" or "2".

    Closes-Bug: #1395841

    Change-Id: I48a95b7562c10bd68d777be408dcfa22cb05ec6a