remove unused rpc method get_active_networks

This method was originally left for backwards compatibility during
an upgrade of neutron. It stopped being used in havana so I think it
should be safe to remove now.

Closes-bug: #1583835
Change-Id: I503d10ee59ba2fa046b5030e8281fd41a49ee74e

neutron/api/rpc/handlers/dhcp_rpc.py

@@ -67,9 +67,13 @@ class DhcpRpcCallback(object):
     #           DHCP agent since Juno, so similar rationale for not bumping the
     #           major version as above applies here too.
     #     1.5 - Added dhcp_ready_on_ports.
+    #     1.6 - Removed get_active_networks. It's not used by reference
+    #           DHCP agent since Havana, so similar rationale for not bumping
+    #           the major version as above applies here too.
+
     target = oslo_messaging.Target(
         namespace=n_const.RPC_NAMESPACE_DHCP_PLUGIN,
-        version='1.5')
+        version='1.6')
 
     def _get_active_networks(self, context, **kwargs):
         """Retrieve and return a list of the active networks."""
@@ -117,16 +121,6 @@ class DhcpRpcCallback(object):
                                 "could not complete successfully: %(reason)s"),
                             {"action": action, "net_id": net_id, 'reason': e})
 
-    def get_active_networks(self, context, **kwargs):
-        """Retrieve and return a list of the active network ids."""
-        # NOTE(arosen): This method is no longer used by the DHCP agent but is
-        # left so that neutron-dhcp-agents will still continue to work if
-        # neutron-server is upgraded and not the agent.
-        host = kwargs.get('host')
-        LOG.debug('get_active_networks requested from %s', host)
-        nets = self._get_active_networks(context, **kwargs)
-        return [net['id'] for net in nets]
-
     def _group_by_network_id(self, res):
         grouped = {}
         keyfunc = operator.itemgetter('network_id')

neutron/tests/unit/api/rpc/handlers/test_dhcp_rpc.py

@@ -45,19 +45,6 @@ class TestDhcpRpcCallback(base.BaseTestCase):
         self.utils_p = mock.patch('neutron.plugins.common.utils.create_port')
         self.utils = self.utils_p.start()
 
-    def test_get_active_networks(self):
-        plugin_retval = [dict(id='a'), dict(id='b')]
-        self.plugin.get_networks.return_value = plugin_retval
-
-        networks = self.callbacks.get_active_networks(mock.Mock(), host='host')
-
-        self.assertEqual(networks, ['a', 'b'])
-        self.plugin.assert_has_calls(
-            [mock.call.get_networks(mock.ANY,
-                                    filters=dict(admin_state_up=[True]))])
-
-        self.assertEqual(len(self.log.mock_calls), 1)
-
     def test_group_by_network_id(self):
         port1 = {'network_id': 'a'}
         port2 = {'network_id': 'b'}