Refactor route clearing to linux interface

The code for clearing routes currently lives inside the
service_instance module but it belongs better inside the linux
interface ones.

This patch refactors it into there, which can allow for a true
noop driver as all network operations would happen inside that
section.

Change-Id: I9fa29e9e5ed7dd2c620b56efab559f4cec25aced
(cherry picked from commit e7858ad084)

manila/network/linux/interface.py

@@ -65,7 +65,7 @@ class LinuxInterfaceDriver(object):
         self.conf = CONF
 
     @device_name_synchronized
-    def init_l3(self, device_name, ip_cidrs, namespace=None):
+    def init_l3(self, device_name, ip_cidrs, namespace=None, clear_cidrs=[]):
         """Set the L3 settings for the interface using data from the port.
 
         ip_cidrs: list of 'X.X.X.X/YY' strings
@@ -73,6 +73,9 @@ class LinuxInterfaceDriver(object):
         device = ip_lib.IPDevice(device_name,
                                  namespace=namespace)
 
+        for cidr in clear_cidrs:
+            device.route.clear_outdated_routes(cidr)
+
         previous = {}
         for address in device.addr.list(scope='global', filters=['permanent']):
             previous[address['cidr']] = address['ip_version']

manila/share/drivers/service_instance.py

@@ -984,17 +984,19 @@ class NeutronNetworkHelper(BaseNetworkhelper):
         LOG.debug("Plug interface into host - interface_name: %s, "
                   "device: %s, port: %s", interface_name, device, port)
         self.vif_driver.plug(interface_name, port['id'], port['mac_address'])
+        cidrs_to_clear = []
         ip_cidrs = []
         for fixed_ip in port['fixed_ips']:
             subnet = self.neutron_api.get_subnet(fixed_ip['subnet_id'])
             if clear_outdated_routes:
-                device.route.clear_outdated_routes(subnet['cidr'])
+                cidrs_to_clear.append(subnet['cidr'])
 
             net = netaddr.IPNetwork(subnet['cidr'])
             ip_cidr = '%s/%s' % (fixed_ip['ip_address'], net.prefixlen)
             ip_cidrs.append(ip_cidr)
 
-        self.vif_driver.init_l3(interface_name, ip_cidrs)
+        self.vif_driver.init_l3(interface_name, ip_cidrs,
+                                clear_cidrs=cidrs_to_clear)
 
     @utils.synchronized("service_instance_get_service_port", external=True)
     def _get_service_port(self, network_id, subnet_id, device_id):

manila/tests/network/linux/test_interface.py

@@ -98,9 +98,11 @@ class TestABCDriver(TestBase):
         self.mock_object(bc, '_remove_outdated_interfaces')
 
         ns = '12345678-1234-5678-90ab-ba0987654321'
-        bc.init_l3('tap0', ['192.168.1.2/24'], namespace=ns)
+        bc.init_l3('tap0', ['192.168.1.2/24'], namespace=ns,
+                   clear_cidrs=['192.168.0.0/16'])
         self.ip_dev.assert_has_calls(
             [mock.call('tap0', namespace=ns),
+             mock.call().route.clear_outdated_routes('192.168.0.0/16'),
              mock.call().addr.list(scope='global', filters=['permanent']),
              mock.call().addr.add(4, '192.168.1.2/24', '192.168.1.255'),
              mock.call().addr.delete(4, '172.16.77.240/24'),

manila/tests/share/drivers/test_service_instance.py

@@ -2151,8 +2151,10 @@ class NeutronNetworkHelperTestCase(test.TestCase):
             mock.call(fake_subnet_admin['id'])])
         instance.vif_driver.init_l3.assert_has_calls([
             mock.call(interface_name_service,
-                      ['10.254.0.2/%s' % fake_division_mask]),
+                      ['10.254.0.2/%s' % fake_division_mask],
-            mock.call(interface_name_admin, ['10.0.0.4/24'])])
+                      clear_cidrs=[]),
+            mock.call(interface_name_admin, ['10.0.0.4/24'],
+                      clear_cidrs=[fake_subnet_admin['cidr']])])
         service_instance.ip_lib.IPDevice.assert_has_calls([
             mock.call(interface_name_service),
             mock.call(interface_name_admin)])