API client object like novaclient is created every time openstack_dashboard/api methods are called

[Akihiro Motoki]

In API modules in openstack_dashboard api such as novaclient, neutronclient and so on, API client objects (novaclient, neutronclient...) are created every time openstack_dashboard/api methods are called even in a same request.
Recreating API client object leads to recreating API HTTP connections.

In a same request, API client object should be reused as possible as we can to reduce the number of connections to backend servers.

Note that keystoneclient in openstack_dashboard/api is the only module which implements the client object caching.[1]

[1] http://git.openstack.org/cgit/openstack/horizon/tree/openstack_dashboard/api/keystone.py#n121

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/111654

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/111654
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=69e0d812f294aefcff6f551ad2dd264497ed9215
Submitter: Jenkins
Branch: master

commit 69e0d812f294aefcff6f551ad2dd264497ed9215
Author: Akihiro Motoki <email address hidden>
Date: Mon Aug 4 15:07:04 2014 +0900

    Reuse API client object in a request

    Previously API client object like novaclient are created
    every time methods in openstack_dashboard/api.
    It leads to regeneration of API HTTP connections.
    This commit caches API client object for a WSGI request
    to reduce the number of HTTP connection to backends.
    As WSGI request object is recreated, a cached API client
    object will live in a single request to Horizon.

    Change-Id: I66620b3b0a2737c7232d91006e65d0fabbd3090b
    Closes-Bug: #1352144