tests: fix functional tests

Neutron introduces an additional layer of protection when it comes
to dead VLANs, however, the VPNaaS did not have that change in it's
tests which meant that traffic was not reachable inside the
functional tests[1].

This patch changes the base class of the TestIPSecBase to use the
L3AgentTestFramework instead, and does a small refactor of the
setUp() function as well to remove extra calls.

This should stop any further changes in Neutron from breaking VPNaaS
since hopefully that class will carry the fixes down.  However, there
are a lot of duplicated code from the base class into this one,
however, this patch is focused at making a simple backportable
change for now.  Long term, it would be good to drop more of the
redundant code in there.

[1]: I0391dd24224f8656a09ddb002e7dae8783ba37a4

Change-Id: I04793caeaa71adbb1abcbda58aa43e63ce51d1e6

neutron_vpnaas/tests/functional/common/test_scenario.py

@@ -17,7 +17,6 @@ from unittest import mock
 
 import netaddr
 from neutron.agent.common import ovs_lib
-from neutron.agent.l3 import agent as neutron_l3_agent
 from neutron.agent.l3 import l3_agent_extensions_manager as ext_manager
 from neutron.agent.l3 import namespaces as n_namespaces
 from neutron.agent.l3 import router_info
@@ -33,7 +32,7 @@ from neutron.conf import common as conf_common
 from neutron.services.provider_configuration import serviceprovider_opts
 from neutron.tests.common import l3_test_common
 from neutron.tests.common import net_helpers
-from neutron.tests.functional import base
+from neutron.tests.functional.agent.l3 import framework
 from neutron_lib import constants
 from neutron_lib.utils import net as n_utils
 from oslo_config import cfg
@@ -291,13 +290,12 @@ class SiteInfoWithHaRouter(SiteInfo):
         return info
 
 
-class TestIPSecBase(base.BaseSudoTestCase):
+class TestIPSecBase(framework.L3AgentTestFramework):
     NESTED_NAMESPACE_SEPARATOR = '@'
 
     def setUp(self):
         super(TestIPSecBase, self).setUp()
         common_config.register_common_config_options()
-        mock.patch('neutron.agent.l3.agent.L3PluginApi').start()
         mock.patch('neutron_vpnaas.services.vpn.device_drivers.ipsec.'
             'IPsecVpnDriverApi').start()
         # avoid report_status running periodically
@@ -318,9 +316,6 @@ class TestIPSecBase(base.BaseSudoTestCase):
         # Can reproduce the exception in the test only
         ip_lib.send_ip_addr_adv_notif = mock.Mock()
 
-        self.conf = self._configure_agent('agent1')
-        self.agent = neutron_l3_agent.L3NATAgentWithStateReport('agent1',
-                                                                self.conf)
         self.vpn_agent = vpn_agent.L3WithVPNaaS(self.conf)
         self.driver = self.vpn_agent.device_drivers[0]
         self.driver.agent_rpc.get_vpn_services_on_host = mock.Mock(