Add a namespace prefix to glance hardware properties used by libvirt

[Daniel Berrange]

In the following two commits

  commit 99ddc0d2ad7f2f9c27deaac08559eb794845afc3
  Author: Daniel P. Berrange <email address hidden>
  Date: Fri Feb 8 16:59:32 2013 +0000

    Allow VIF model to be chosen per image

  commit 66a7f044f5143feaf7046cebafea3df3ea95e04b
  Author: Daniel P. Berrange <email address hidden>
  Date: Wed Jan 16 12:38:23 2013 +0000

    Allow disk driver to be chosen per image

support was introduced for the Nova libvirt driver to read glance image properties for customizing the hardware of a guest.

eg the user would set

      # glance image-update \
               --property disk_bus=ide \
               --property cdrom_bus=ide \
               --property vif_model=e1000 \
               f16-x86_64-openstack-sda

These properties are equally applicable to other hypervisor drivers and thus ought to be documented as "standard" metadata properties, so we don't get each driver doing its own thing [1]

It was suggested on IRC that we might want to first change the names used here to have some kind of standard "prefix" to group all hardware config properties together, eg prefix then with 'hw_' or 'hw:'. So instead of the above names, use

      # glance image-update \
               --property hw_disk_bus=ide \
               --property hw_cdrom_bus=ide \
               --property hw_vif_model=e1000 \
               f16-x86_64-openstack-sda

Any such change must be complete prior to Grizzly GA release, to avoid back-compat problems.

See also http://lists.openstack.org/pipermail/openstack-dev/2013-February/005936.html

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/23081

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/23081
Committed: http://github.com/openstack/nova/commit/2c9eba280a78e4159267d4a56a09df9076c844d3
Submitter: Jenkins
Branch: master

commit 2c9eba280a78e4159267d4a56a09df9076c844d3
Author: Daniel P. Berrange <email address hidden>
Date: Mon Feb 25 15:47:35 2013 +0000

    Add a 'hw_' namespace to glance hardware config properties

    This updates the libvirt driver to use a 'hw_' prefix on
    the names of hardware config properties it looks up for
    glance images. Thus the new syntax for setting custom
    hardware properties is

          # glance image-update \
                   --property hw_disk_bus=ide \
                   --property hw_cdrom_bus=ide \
                   --property hw_vif_model=e1000 \
                   f16-x86_64-openstack-sda

    There is no back-compat support for the previous 'disk_bus',
    'cdrom_bus' and 'vif_model' names, since they were never
    made available in any formal release, only development
    snapshots.

    DocImpact
    Blueprint: libvirt-custom-hardware
    Fixes bug 1132739
    Change-Id: Ic15ef0eba065113b35bbb2713be2532c858c3534
    Signed-off-by: Daniel P. Berrange <email address hidden>