When virt-type is changed for nova-compute it should install packages for that virt-type

[David Ames]

If virt-type is changed in nova-compute the packages for the new virt-type are never installed.

apt_install(determine_packages(), fatal=True) happens in the install hook and should probably run in config-changed.

If we do not support changing of virt-type we should communicate this in the config.yaml, README and react to a change in the code.

[James Page (james-page)]

Definitely not suppoorted - think of the use case where the machine is already running cloud instances; we should lock it in on install and not allow it to be changed.

Immutable config via Juju would be nice :-).

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/409423

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/409423
Committed: https://git.openstack.org/cgit/openstack/charm-nova-compute/commit/?id=ca8dcdeaa88818d9de5814c4953986f74fb035e8
Submitter: Jenkins
Branch: master

commit ca8dcdeaa88818d9de5814c4953986f74fb035e8
Author: Sandor Zeestraten <email address hidden>
Date: Sat Dec 10 08:51:18 2016 +0100

    Update config description for virt-type

    The charm allows changing of the virt-type configuration option after
    deployment, however this is not supported as noted in LP #1623679.

    This updates the description for virt-type to include a note that changing
    after deployment is not supported.

    Change-Id: I91f5e814e65f3cc622a1001adb9bf7850b74d6fd
    Related-Bug: #1623679
    Related-Bug: #1539489
    Related-Bug: #1626416