[gnuoy,r=james-page] Add l2population driver support, on by default.

config.yaml

@@ -123,3 +123,10 @@ options:
     description: |
       SSL CA to use with the certificate and key provided - this is only
       required if you are providing a privately signed ssl_cert and ssl_key.
+  l2-population:
+    type: boolean
+    default: True
+    description: |
+      Populate the forwarding tables of virtual switches (LinuxBridge or OVS),
+      to decrease broadcast traffics inside the physical networks fabric while
+      using overlays networks (VXLan, GRE).

hooks/neutron_api_context.py

@@ -11,6 +11,11 @@ from charmhelpers.contrib.hahelpers.cluster import (
 )
 
 
+def get_l2population():
+    plugin = config('neutron-plugin')
+    return config('l2-population') if plugin == "ovs" else False
+
+
 class ApacheSSLContext(context.ApacheSSLContext):
 
     interfaces = ['https']
@@ -49,6 +54,10 @@ class NeutronCCContext(context.NeutronContext):
     def neutron_security_groups(self):
         return config('neutron-security-groups')
 
+    @property
+    def neutron_l2_population(self):
+        return get_l2population()
+
     # Do not need the plugin agent installed on the api server
     def _ensure_packages(self):
         pass
@@ -60,6 +69,7 @@ class NeutronCCContext(context.NeutronContext):
     def __call__(self):
         from neutron_api_utils import api_port
         ctxt = super(NeutronCCContext, self).__call__()
+        ctxt['l2_population'] = self.neutron_l2_population
         ctxt['external_network'] = config('neutron-external-network')
         ctxt['verbose'] = config('verbose')
         ctxt['debug'] = config('debug')

hooks/neutron_api_hooks.py

@@ -46,6 +46,7 @@ from neutron_api_utils import (
     register_configs,
     restart_map,
 )
+from neutron_api_context import get_l2population
 
 from charmhelpers.contrib.hahelpers.cluster import (
     get_hacluster_config,
@@ -269,7 +270,8 @@ def neutron_api_relation_changed():
 @hooks.hook('neutron-plugin-api-relation-joined')
 def neutron_plugin_api_relation_joined(rid=None):
     relation_data = {
-        'neutron-security-groups': config('neutron-security-groups')
+        'neutron-security-groups': config('neutron-security-groups'),
+        'l2-population': get_l2population(),
     }
     relation_set(relation_id=rid, **relation_data)
 

templates/icehouse/ml2_conf.ini

@@ -6,7 +6,7 @@
 [ml2]
 type_drivers = gre,vxlan
 tenant_network_types = gre,vxlan
-mechanism_drivers = openvswitch
+mechanism_drivers = openvswitch,l2population
 
 [ml2_type_gre]
 tunnel_id_ranges = 1:1000

unit_tests/test_neutron_api_context.py

@@ -129,6 +129,7 @@ class NeutronAPIContextsTest(CharmTestCase):
             'external_network': 'bob',
             'neutron_bind_port': self.api_port,
             'verbose': True,
+            'l2_population': True,
         }
         napi_ctxt = context.NeutronCCContext()
         with patch.object(napi_ctxt, '_ensure_packages'):

unit_tests/test_neutron_api_hooks.py

@@ -30,6 +30,9 @@ TO_PATCH = [
     'determine_ports',
     'do_openstack_upgrade',
     'execd_preinstall',
+    'get_iface_for_address',
+    'get_l2population',
+    'get_netmask_for_address',
     'is_leader',
     'is_relation_made',
     'log',
@@ -262,10 +265,12 @@ class NeutronAPIHooksTests(CharmTestCase):
         self._call_hook('neutron-api-relation-changed')
         self.assertTrue(self.CONFIGS.write.called_with(NEUTRON_CONF))
 
-    def test_neutron_plugin_api_relation_joined(self):
+    def test_neutron_plugin_api_relation_joined_nol2(self):
         _relation_data = {
             'neutron-security-groups': False,
+            'l2-population': False,
         }
+        self.get_l2population.return_value = False
         self._call_hook('neutron-plugin-api-relation-joined')
         self.relation_set.assert_called_with(
             relation_id=None,