[Feature] Neutron-API and nova-compute support for Infoblox IPAM driver

[Michael Skalka]

Infoblox is a popular solution for DNS and asset management and network automation in complex network environments. The Infoblox IPAM driver for Neutron has been available since the Liberty release of OpenStack and is compatible up to Queens.

Integration of these drivers is well documented: https://github.com/openstack/networking-infoblox/blob/master/doc/source/installation.rst and is a good candidate for charming as the steps are reproducible in our charm code.

Integration of this functionality should be added to the Neutron-API and Nova-compute charms with the following:
- Add a infoblox-section to the Neutron-API parts templates to add a stanza for a single Infoblox endpoint.
- Adding an Infoblox context into the Neutron-API charm.
- Adding a check in the Nova-Compute/Neutron-API relation context to add the appropriate settings to nova.conf if Infoblox is enabled in Neutron.
- Adding metadata definitions for an Infoblox interface to both the Neutron-API and Nova-compute charms.

In addition, development of an Infoblox subordinate charm to handle capturing configuration, installing packages, and controlling the IPAM service state will have to be done.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/584439

[Ryan Beisner (1chb1n)]

FYI, track the related reviews here:
https://review.openstack.org/#/q/topic:bug/1776689+(status:open+OR+status:merged)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/584439
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-api/commit/?id=92a10628303e9344385b9ad0c92661a9bb3c0b2e
Submitter: Zuul
Branch: master

commit 92a10628303e9344385b9ad0c92661a9bb3c0b2e
Author: Michael Skalka <email address hidden>
Date: Wed Jun 6 12:30:56 2018 -0400

    Add support for Infoblox IPAM configuration via subordinate charm.

    This change adds infoblox-api relation which allows neutron-server
    to publish events to a remote infoblox server. Additionally this
    change enables IPAM for the neutron service, which forces neutron
    to authorize any network changes against the target Infoblox
    server.

    This change adds the proper hooks, context, and templates to add
    infobox configuration to /etc/neutron/neutron.conf, passed by the
    infoblox subordinate charm.

    Closes-Bug: 1776689

    Change-Id: Ib11377bd61c2b3fed5104ba0a423073a15cc18a2