Fix misc unit test failures

A recent commit landed with failing unit tests, but due to
gate misconfiguration this was not picked up during pre-commit
testing.

Fixup offending code.

Change-Id: I20488efabe91b2423c85dd4e7474cbaf9a0a0261

hooks/neutron_ovs_utils.py

@@ -393,6 +393,7 @@ def configure_ovs():
     if ext_port_ctx and ext_port_ctx['ext_port']:
         add_bridge_port(EXT_BRIDGE, ext_port_ctx['ext_port'])
 
+    bridgemaps = None
     if not use_dpdk():
         portmaps = DataPortContext()()
         bridgemaps = parse_bridge_mappings(config('bridge-mappings'))
@@ -420,7 +421,8 @@ def configure_ovs():
 
     target = config('ipfix-target')
     bridges = [INT_BRIDGE, EXT_BRIDGE]
-    bridges.extend(bridgemaps.values())
+    if bridgemaps:
+        bridges.extend(bridgemaps.values())
 
     if target:
         for bridge in bridges:

tox.ini

@@ -27,6 +27,11 @@ basepython = python3.5
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 
+[testenv:py36]
+basepython = python3.6
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/test-requirements.txt
+
 [testenv:pep8]
 basepython = python2.7
 deps = -r{toxinidir}/requirements.txt

unit_tests/test_neutron_ovs_utils.py

@@ -501,11 +501,12 @@ class TestNeutronOVSUtils(CharmTestCase):
             any_order=True
         )
 
+    @patch.object(nutils, 'use_dvr')
     @patch('charmhelpers.contrib.openstack.context.config')
-    def test_configure_ovs_enable_ipfix(self, mock_config):
+    def test_configure_ovs_enable_ipfix(self, mock_config, mock_use_dvr):
+        mock_use_dvr.return_value = False
         mock_config.side_effect = self.test_config.get
         self.config.side_effect = self.test_config.get
-        self.test_config.set('plugin', 'ovs')
         self.test_config.set('ipfix-target', '127.0.0.1:80')
         nutils.configure_ovs()
         self.enable_ipfix.assert_has_calls([