Forgot the Nova Neutron API wrapper in initial commit.

No wonder I couldn't figure out (again) how the Nova vif driver was
figuring out which physical OVS bridge to plug a Capnet VM NIC into...
I had forgotten about this little guy.  This is a simple wrapper for
the Nova network API Neutron driver that adds a couple of
Capnet-specific fields into the VIF info.  This seemed to be the way
to do it at the time... maybe there's a way to not have to do it
though.

compute_capnet/network/neutronv2/api.py

+
+from oslo_config import cfg
+from oslo_log import log as logging
+
+from nova.network.neutronv2.api import API as NeutronAPI
+
+from networking_capnet.common import config as cn_config
+
+
+LOG = logging.getLogger(__name__)
+
+cfg.CONF.import_group('CAPNET','networking_capnet.common.config')
+
+
+class API(NeutronAPI):
+    def __init__(self, skip_policy_check=False):
+        super(API, self).__init__(skip_policy_check=skip_policy_check)
+        
+        self.bridge_mappings = {}
+        try:
+            for mapping in cfg.CONF.CAPNET.bridge_mappings:
+                sma = mapping.split(':')
+                self.bridge_mappings[sma[0]] = sma[1]
+                pass
+            LOG.info("Initialized Capnet bridge_mappings: %s"
+                     % (str(self.bridge_mappings)))
+        except:
+            LOG.exception("Failed to initialize Capnet Neutron Interface Driver;"
+                          " will effectively revert to openvswitch driver")
+        pass
+    
+    def _nw_info_build_network(self, port, networks, subnets):
+        (network, ovs_interfaceid) = \
+            super(API,self)._nw_info_build_network(port,networks,subnets)
+            
+        LOG.info("port = %s, networks = %s, subnets = %s"
+                 % (str(port),str(networks),str(subnets)))
+        
+        for net in networks:
+            if net['id'] == port['network_id'] \
+                and 'provider:physical_network' in net \
+                and net['provider:physical_network'] in self.bridge_mappings:
+                network['physical_network'] = net['provider:physical_network']
+                network['bridge'] = \
+                    self.bridge_mappings[network['physical_network']]
+                ovs_interfaceid = port['id']
+                
+                LOG.info("updated bridge for port %s network %s %s to %s/%s"
+                         % (port['id'],net['name'],net['id'],
+                            network['physical_network'],network['bridge']))
+                break
+            pass
+        
+        return (network, ovs_interfaceid)
+        
+    pass