This patchset implements new relation ("external-dns") using new
interface ("designate") between designate and neutron-api charms.
The following charm options have been added:
* "reverse-dns-lookup"
* "ipv4-ptr-zone-prefix-size"
* "ipv6-ptr-zone-prefix-size"
The patchset contains changes to various items (config files, hooks,
template files and unit tests).
When neutron-api is related to designate, the notification topic
previously used to send notification events to designate will be
disabled (as the DNS driver method is preferred).
Change-Id: I13b2ab39bd1daac13112398762f2be06022594b0
Closes-Bug: #1704769
95c045d1ce