let metaplugin work with plugin which has not l3 extension support

Fixes bug 1074183
Also Fixes bug 1074184 ( fix get_nework call with fields)

Change-Id: I3bfdb22dd3be8a58cd884629dc5e3385730bb1bc

quantum/plugins/metaplugin/meta_quantum_plugin.py

@@ -153,7 +153,9 @@ def _extend_network_dict(self, context, network):
         network[FLAVOR_NETWORK] = flavor
 
     def _is_l3_plugin(self, plugin):
-        return 'router' in plugin.supported_extension_aliases
+        if hasattr(plugin, 'supported_extension_aliases'):
+            return 'router' in plugin.supported_extension_aliases
+        return False
 
     def create_network(self, context, network):
         n = network['network']
@@ -204,7 +206,7 @@ def get_network(self, context, id, fields=None):
             self._extend_network_dict_l3(context, net)
         if not fields or FLAVOR_NETWORK in fields:
             self._extend_network_dict(context, net)
-        if fields and not id in fields:
+        if fields and not 'id' in fields:
             del net['id']
         return net
 

quantum/tests/unit/test_db_plugin.py

@@ -1666,6 +1666,17 @@ def test_list_networks_with_parameters(self):
                 self.assertEquals(res['networks'][0]['name'],
                                   net2['network']['name'])
 
+    def test_list_networks_with_fields(self):
+        with self.network(name='net1') as net1:
+            req = self.new_list_request('networks',
+                                        params='fields=name')
+            res = self.deserialize('json', req.get_response(self.api))
+            self.assertEquals(1, len(res['networks']))
+            self.assertEquals(res['networks'][0]['name'],
+                              net1['network']['name'])
+            self.assertEquals(None,
+                              res['networks'][0].get('id'))
+
     def test_list_networks_with_parameters_invalid_values(self):
         with self.network(name='net1', admin_status_up=False) as net1:
             with self.network(name='net2') as net2: