Add way to know topology is based on containers

It is important in some cases to know if cloud topology is
contenerized (like TripleO) or not (like e.g. Devstack).
In case of contenerized topology, we need for now to skip
radvd related faults test as this isn't run in side car container
so it's gone always when neutron-l3-agent is stopped.

Change-Id: If7f93c21814cfc75cdd3d32900403dc978b53afe

tobiko/openstack/topology/_topology.py

@@ -162,6 +162,8 @@ class OpenStackTopology(tobiko.SharedFixture):
         'neutron-ovs-agent': 'devstack@q-agt',
     }
 
+    has_containers = False
+
     def __init__(self):
         super(OpenStackTopology, self).__init__()
         self._reachable_ips = set()

tobiko/tests/faults/agents/test_neutron_agents.py

@@ -278,6 +278,13 @@ class L3AgentTest(testtools.TestCase, AgentTestMixin):
         return True
 
     def test_radvd_during_stop_l3_agent(self):
+        os_topology = topology.get_openstack_topology()
+        if os_topology.has_containers:
+            self.skip("Radvd process is currently run directly in "
+                      "neutron-l3-agent container so it will be always killed "
+                      "when neutron-l3-agent container is killed and this "
+                      "test is not needed")
+
         if not self._is_radvd_process_expected():
             self.skip("Radvd process is not expected to be run on router %s" %
                       self.router_id)

tobiko/tripleo/topology.py

@@ -33,6 +33,8 @@ class TripleoTopology(topology.OpenStackTopology):
         'neutron-ovs-agent': 'tripleo_neutron_ovs_agent',
     }
 
+    has_containers = True
+
     def discover_nodes(self):
         self.discover_undercloud_nodes()
         self.discover_overcloud_nodes()