Internal file cache breaks with unicode keys

[Florian Fuchs]

ironicclient uses an internal file cache (dogpile.cache), with bdm as backend -- which in py2 uses the bsddb package from the standardlib. However, bsddb doesn't accept unicode as keys and raises a TypeError. For example if the ironic_url argument passed to client.get_client is a unicode string, which is then used as part of the cache key).

Proposed fix:

dogpile.cache provides a "key_mangler" config param to use in combination with the bsddb backend which solves this issue.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/220475

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/220475
Committed: https://git.openstack.org/cgit/openstack/python-ironicclient/commit/?id=8fa6d32fbeeb5d990bd7f1c027e3de5b993b50ac
Submitter: Jenkins
Branch: master

commit 8fa6d32fbeeb5d990bd7f1c027e3de5b993b50ac
Author: Florian Fuchs <email address hidden>
Date: Fri Sep 4 13:53:23 2015 +0200

    Fixes file cache TypeError

    The internal cache (common.filecache) uses dogpile.cache's dbm backend,
    which uses the bsddb package from the standardlib (in py2 only). bsddb
    however breaks with a TypeError if the cache key is a unicode string.

    This change fixes this by using the ``key_mangler`` arg on cache
    creation, which (according to the dogpile.cache docs) is to be used with
    dbm/bsddb.

    Change-Id: Ie4911e31567d773357da99af3ded0548ad0b7db1
    Closes-Bug: #1492205