The current test code for octavia requires DVR extensions to be
present on the Neutron API server.
We need to conditionally enable this based on enabled extensions to
allow the test to operate on multiple deployment configurations.
The existing code lead to intermittent failures as there are a few
Neutron ports tagged with ``device:owner`` ``compute:nova`` that
has nothing to do with our payload instances.
Get IP information by asking Nova to list instances instead.
Setup can be used standalone by other charms consuming the
``octavia-diskimage-retrofit`` charm for their testing purposes.
Tests the charms actions.
Full end to end test will be done by consuming this charm in the
``octavia`` charm tests.