Can't override host in cinder-volume backend

[Vish Ishaya]

Backends for external storage devices can achieve HA by specifying the same host for multiple copies. This allows any of the copies to handle messages that are normally sent to the "owner" of the volume. Unfortunately host cannot be set per backend so you can't have multiple backends where one shares a hostname with other nodes and the other backend has a unique hostname.

You need to be able to override the host setting in the backend configuration to make this work.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/95022

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/95022
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=c0630419f45f0b34bae5702ccecedf0b398f91b0
Submitter: Jenkins
Branch: master

commit c0630419f45f0b34bae5702ccecedf0b398f91b0
Author: Vishvananda Ishaya <email address hidden>
Date: Thu May 22 14:49:20 2014 -0700

    Allow host config to be overriden in backend

    This allows you to specify host=XXX in your backend configuration
    to override the host value that is specified in the DEFAULT section,
    allowing for some backends to share a hostname while others can
    have unique names.

    Change-Id: Ie8894a7cebf350dc2d50567058a765482b9d97d7
    Closes-bug: #1322366

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/103549

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/103549
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=04c7431858157e19e42cad88e6197747063e7b86
Submitter: Jenkins
Branch: stable/icehouse

commit 04c7431858157e19e42cad88e6197747063e7b86
Author: Vishvananda Ishaya <email address hidden>
Date: Thu May 22 14:49:20 2014 -0700

    Allow host config to be overriden in backend

    This allows you to specify host=XXX in your backend configuration
    to override the host value that is specified in the DEFAULT section,
    allowing for some backends to share a hostname while others can
    have unique names.

    Closes-bug: #1322366
    DocImpact: When using multi-backend, each driver can now specify
               'host' parameter.
    (cherry picked from commit c0630419f45f0b34bae5702ccecedf0b398f91b0)
    Change-Id: Ie8894a7cebf350dc2d50567058a765482b9d97d7