Add fullstack test with OVS arp_responder

Now that fullstack uses a modern OVS we may finally have
an OVS ARP responder test. The code will now have implicit
coverage. It previously was not run in any functional or
integration test.

Change-Id: I3db3185a08b7cc546dee9e711f5bda9143752f86
Related-Bug: #1623849
(cherry picked from commit 033903aec0)

doc/source/devref/testing_coverage.rst

@@ -65,7 +65,7 @@ such as what L2 agent to use or what type of routers to create.
 +------------------------+------------+------------+------------+------------+------------+------------+
 | DHCP HA                | V          |            |            | amuller    |            |            |
 +------------------------+------------+------------+------------+------------+------------+------------+
-| OVS ARP responder      | V          | X*         |            | X*         |            |            |
+| OVS ARP responder      | V          | X*         |            | Implicit   |            |            |
 +------------------------+------------+------------+------------+------------+------------+------------+
 | OVS agent              | V          | V          |            | V          |            | V          |
 +------------------------+------------+------------+------------+------------+------------+------------+
@@ -90,9 +90,7 @@ such as what L2 agent to use or what type of routers to create.
   layers, nor for the L3 agent changes. This has been an area of repeated
   regressions.
 * The functional job now compiles OVS 2.5 from source, enabling testing
-  features that we previously could not. The OVS ARP responder is one such
-  feature. Modifying the fullstack job to use OVS 2.5 as well will enable
-  testing the OVS ARP responder implicitly.
+  features that we previously could not.
 
 Missing Infrastructure
 ----------------------

neutron/tests/fullstack/resources/config.py

@@ -158,6 +158,7 @@ class OVSConfigFixture(ConfigFixture):
             },
             'agent': {
                 'l2_population': str(self.env_desc.l2_pop),
+                'arp_responder': str(self.env_desc.arp_responder),
             }
         })
 

neutron/tests/fullstack/resources/environment.py

@@ -34,12 +34,13 @@ class EnvironmentDescription(object):
     Does the setup, as a whole, support tunneling? How about l2pop?
     """
     def __init__(self, network_type='vxlan', l2_pop=True, qos=False,
-                 mech_drivers='openvswitch,linuxbridge'):
+                 mech_drivers='openvswitch,linuxbridge', arp_responder=False):
         self.network_type = network_type
         self.l2_pop = l2_pop
         self.qos = qos
         self.network_range = None
         self.mech_drivers = mech_drivers
+        self.arp_responder = arp_responder
 
     @property
     def tunneling_enabled(self):

neutron/tests/fullstack/test_connectivity.py

@@ -29,6 +29,7 @@ class BaseConnectivitySameNetworkTest(base.BaseFullStackTestCase):
 
     of_interface = None
     ovsdb_interface = None
+    arp_responder = False
 
     def setUp(self):
         host_descriptions = [
@@ -43,7 +44,8 @@ class BaseConnectivitySameNetworkTest(base.BaseFullStackTestCase):
         env = environment.Environment(
             environment.EnvironmentDescription(
                 network_type=self.network_type,
-                l2_pop=self.l2_pop),
+                l2_pop=self.l2_pop,
+                arp_responder=self.arp_responder),
             host_descriptions)
         super(BaseConnectivitySameNetworkTest, self).setUp(env)
 
@@ -77,8 +79,9 @@ class TestOvsConnectivitySameNetwork(BaseConnectivitySameNetworkTest):
     network_scenarios = [
         ('VXLAN', {'network_type': 'vxlan',
                    'l2_pop': False}),
-        ('GRE and l2pop', {'network_type': 'gre',
-                           'l2_pop': True}),
+        ('GRE-l2pop-arp_responder', {'network_type': 'gre',
+                                     'l2_pop': True,
+                                     'arp_responder': True}),
         ('VLANs', {'network_type': 'vlan',
                    'l2_pop': False})]
     scenarios = testscenarios.multiply_scenarios(