Project list is fetched from Keystone for each request

[Lin Hua Cheng]

For each request coming in, the code in user.authorized_tenants triggers a GET projects to keystone. I think we can cache this value rather than fetching the Project List every request.

The project list doesn't change that often. In any case that the a project-role has been revoke from keystone, keystone will revoke the tokens anyway. With that the user would need to re-authenticate and fetch the new project list.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/53750

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/53750
Committed: https://git.openstack.org/cgit/openstack/django_openstack_auth/commit/?id=bd9fd598e6c2ff11f8c31098cd25c7a42a97d761
Submitter: Jenkins
Branch: master

commit bd9fd598e6c2ff11f8c31098cd25c7a42a97d761
Author: Lin Hua Cheng <email address hidden>
Date: Thu Oct 24 15:23:51 2013 -0700

    Cache the User's Project by Token ID

    Project list fetched for each request. The patches caches the
    project list and uses the token as the key in the cache. When
    the user logout or switch project, the project list is removed
    from the cache.

    Change-Id: I2386d7a342cf02a0252e97cc48c5349ccab8a9eb
    Closes-bug: 1241838