Merge "Check if pool update is needed in reference driver"

neutron/ipam/drivers/neutrondb_ipam/driver.py

@@ -370,11 +370,20 @@ class NeutronDbSubnet(ipam_base.Subnet):
                 subnet_id=self.subnet_manager.neutron_id,
                 ip_address=address)
 
+    def _no_pool_changes(self, session, pools):
+        """Check if pool updates in db are required."""
+        db_pools = self.subnet_manager.list_pools(session)
+        iprange_pools = [netaddr.IPRange(pool.first_ip, pool.last_ip)
+                         for pool in db_pools]
+        return pools == iprange_pools
+
     def update_allocation_pools(self, pools, cidr):
         # Pools have already been validated in the subnet request object which
         # was sent to the subnet pool driver. Further validation should not be
         # required.
         session = self._context.session
+        if self._no_pool_changes(session, pools):
+            return
         self.subnet_manager.delete_allocation_pools(session)
         self.create_allocation_pools(self.subnet_manager, session, pools, cidr)
         self._pools = pools

neutron/tests/unit/ipam/drivers/neutrondb_ipam/test_driver.py

@@ -21,6 +21,7 @@ from neutron_lib import exceptions as n_exc
 from neutron.common import constants as n_const
 from neutron import context
 from neutron.db import api as ndb_api
+from neutron.ipam.drivers.neutrondb_ipam import db_models
 from neutron.ipam.drivers.neutrondb_ipam import driver
 from neutron.ipam import exceptions as ipam_exc
 from neutron.ipam import requests as ipam_req
@@ -460,3 +461,43 @@ class TestNeutronDbIpamSubnet(testlib_api.SqlTestCase,
             ipam_subnet._allocate_specific_ip(self.ctx.session, ip)
 
         self.assertRaises(ipam_exc.IPAllocationFailed, go)
+
+    def test_update_allocation_pools_with_no_pool_change(self):
+        cidr = '10.0.0.0/24'
+        ipam_subnet = self._create_and_allocate_ipam_subnet(
+            cidr)[0]
+        ipam_subnet.subnet_manager.delete_allocation_pools = mock.Mock()
+        ipam_subnet.create_allocation_pools = mock.Mock()
+        alloc_pools = [netaddr.IPRange('10.0.0.2', '10.0.0.254')]
+        # Make sure allocation pools recreation does not happen in case of
+        # unchanged allocation pools
+        ipam_subnet.update_allocation_pools(alloc_pools, cidr)
+        self.assertFalse(
+            ipam_subnet.subnet_manager.delete_allocation_pools.called)
+        self.assertFalse(ipam_subnet.create_allocation_pools.called)
+
+    def _test__no_pool_changes(self, new_pools):
+        id = 'some-id'
+        ipam_subnet = driver.NeutronDbSubnet(id, self.ctx)
+        pools = [db_models.IpamAllocationPool(ipam_subnet_id=id,
+                                              first_ip='192.168.10.20',
+                                              last_ip='192.168.10.41'),
+                 db_models.IpamAllocationPool(ipam_subnet_id=id,
+                                              first_ip='192.168.10.50',
+                                              last_ip='192.168.10.60')]
+
+        ipam_subnet.subnet_manager.list_pools = mock.Mock(return_value=pools)
+        return ipam_subnet._no_pool_changes(self.ctx.session, new_pools)
+
+    def test__no_pool_changes_negative(self):
+        pool_list = [[netaddr.IPRange('192.168.10.2', '192.168.10.254')],
+                     [netaddr.IPRange('192.168.10.20', '192.168.10.41')],
+                     [netaddr.IPRange('192.168.10.20', '192.168.10.41'),
+                      netaddr.IPRange('192.168.10.51', '192.168.10.60')]]
+        for pools in pool_list:
+            self.assertFalse(self._test__no_pool_changes(pools))
+
+    def test__no_pool_changes_positive(self):
+        pools = [netaddr.IPRange('192.168.10.20', '192.168.10.41'),
+                 netaddr.IPRange('192.168.10.50', '192.168.10.60')]
+        self.assertTrue(self._test__no_pool_changes(pools))