Do not create MTU upstart scripts on xenial+

MTU scripts are no longer needed as MAAS 1.9 can set the mtu and
bring up the interfaces.

The charm has no systemd versions of the 'os-charm-phy-mic-mtu'
and 'ext-port' scripts either so for xenial to set mtu sizes
on physical nics use MAAS 1.9 and appropriate network config

Change-Id: I3aa4d2a80a08dd605d4ae08d53f35282017e1009
Partial-Bug: 1566786

hooks/neutron_ovs_utils.py

@@ -271,6 +271,7 @@ def resource_map():
     Dynamically generate a map of resources that will be managed for a single
     hook execution.
     '''
+    drop_config = []
     resource_map = deepcopy(BASE_RESOURCE_MAP)
     if use_dvr():
         resource_map.update(DVR_RESOURCE_MAP)
@@ -285,7 +286,7 @@ def resource_map():
     # Remap any service names as required
     if os_release('neutron-common', base='icehouse') >= 'mitaka':
         # ml2_conf.ini -> openvswitch_agent.ini
-        del resource_map[ML2_CONF]
+        drop_config.append(ML2_CONF)
         # drop of -plugin from service name
         resource_map[NEUTRON_CONF]['services'].remove(
             'neutron-plugin-openvswitch-agent'
@@ -294,10 +295,20 @@ def resource_map():
             'neutron-openvswitch-agent'
         )
         if not use_dpdk():
-            del resource_map[DPDK_INTERFACES]
+            drop_config.append(DPDK_INTERFACES)
     else:
-        del resource_map[OVS_CONF]
-        del resource_map[DPDK_INTERFACES]
+        drop_config.extend([OVS_CONF, DPDK_INTERFACES])
+
+    # Use MAAS1.9 for MTU and external port config on xenial and above
+    if float(lsb_release()['DISTRIB_RELEASE']) >= 16.04:
+        drop_config.extend([EXT_PORT_CONF, PHY_NIC_MTU_CONF])
+
+    for _conf in drop_config:
+        try:
+            del resource_map[_conf]
+        except KeyError:
+            pass
+
     return resource_map
 
 

unit_tests/test_neutron_ovs_utils.py

@@ -274,6 +274,32 @@ class TestNeutronOVSUtils(CharmTestCase):
         [self.assertIn(q_conf, _map.keys()) for q_conf in confs]
         self.assertEqual(_map[nutils.NEUTRON_CONF]['services'], svcs)
 
+    @patch.object(nutils, 'use_dvr')
+    def test_resource_map_mtu_trusty(self, _use_dvr):
+        _use_dvr.return_value = False
+        self.os_release.return_value = 'mitaka'
+        self.lsb_release.return_value = {'DISTRIB_RELEASE': '14.04'}
+        _map = nutils.resource_map()
+        self.assertTrue(nutils.NEUTRON_CONF in _map.keys())
+        self.assertTrue(nutils.PHY_NIC_MTU_CONF in _map.keys())
+        self.assertFalse(nutils.EXT_PORT_CONF in _map.keys())
+        _use_dvr.return_value = True
+        _map = nutils.resource_map()
+        self.assertTrue(nutils.EXT_PORT_CONF in _map.keys())
+
+    @patch.object(nutils, 'use_dvr')
+    def test_resource_map_mtu_xenial(self, _use_dvr):
+        _use_dvr.return_value = False
+        self.os_release.return_value = 'mitaka'
+        self.lsb_release.return_value = {'DISTRIB_RELEASE': '16.04'}
+        _map = nutils.resource_map()
+        self.assertTrue(nutils.NEUTRON_CONF in _map.keys())
+        self.assertFalse(nutils.PHY_NIC_MTU_CONF in _map.keys())
+        self.assertFalse(nutils.EXT_PORT_CONF in _map.keys())
+        _use_dvr.return_value = True
+        _map = nutils.resource_map()
+        self.assertFalse(nutils.EXT_PORT_CONF in _map.keys())
+
     @patch.object(nutils, 'use_dvr')
     def test_restart_map(self, _use_dvr):
         _use_dvr.return_value = False