Comment 8 for bug 1157765

Reviewed: https://review.openstack.org/25369
Committed: http://github.com/openstack/glance/commit/5b4d21d8f97c2c83222893b3b585f80d2108e8bf
Submitter: Jenkins
Branch: stable/folsom

commit 5b4d21d8f97c2c83222893b3b585f80d2108e8bf
Author: Flaper Fesp <email address hidden>
Date: Thu Mar 21 10:05:05 2013 +0100

    Check if creds are present and not None

    Currently, KeystoneStrategy checks whether the required credentials are
    present in the creds dict but it doesn't check whether they are valid or
    not.

    This patch checks whether the required creds are present and not None
    otherwise a MissingCredentials exception will be raised.

    Note: No need for checking parameters' values types since they'll be
    instances of basestring once set otherwise they'll be None.

    Fixes bug 1157765

    Change-Id: I664a604c3cbf2fca60a88c4d887cd9a4b678c8a5