Remove any IPAM allocation if port bulk creation fails

During the port bulk creation, if an IPAM allocation fails (for
example, if the IP address is outside of the subnet CIDR), the
other IPAM allocations already created are deleted before raising
the exception.

Conflicts:
  neutron/tests/unit/plugins/ml2/test_plugin.py

Closes-Bug: #2039550
Change-Id: I7fd6e38016d099c03f80874bfa1fb8bdaff8bd2c
(cherry picked from commit 71a7abb498)
(cherry picked from commit a4c03671f2)

neutron/plugins/ml2/plugin.py

@@ -1601,10 +1601,9 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         for port in port_list:
             self._before_create_port(context, port)
 
-        port_list, net_cache = self.allocate_macs_and_ips_for_ports(
-            context, port_list)
-
         try:
+            port_list, net_cache = self.allocate_macs_and_ips_for_ports(
+                context, port_list)
             return self._create_port_bulk(context, port_list, net_cache)
         except Exception:
             with excutils.save_and_reraise_exception():
@@ -1612,7 +1611,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                 # deallocated now
                 for port in port_list:
                     self.ipam.deallocate_ips_from_port(
-                        context, port, port['ipams'])
+                        context, port, port.get('ipams'))
 
     @db_api.retry_if_session_inactive()
     def _create_port_bulk(self, context, port_list, network_cache):

neutron/tests/unit/plugins/ml2/test_plugin.py

@@ -55,6 +55,7 @@ from neutron.db import ipam_pluggable_backend
 from neutron.db import provisioning_blocks
 from neutron.db import securitygroups_db as sg_db
 from neutron.db import segments_db
+from neutron.ipam import driver
 from neutron.objects import base as base_obj
 from neutron.objects import ports as port_obj
 from neutron.objects import router as l3_obj
@@ -1730,6 +1731,39 @@ class TestMl2PortsV2(test_plugin.TestPortsV2, Ml2PluginV2TestCase):
             ports_out = self.plugin.create_port_bulk(ctx, ports_in)
             self.assertEqual(edo, ports_out[0]['extra_dhcp_opts'])
 
+    def test_create_ports_bulk_with_wrong_fixed_ips(self):
+        cidr = '10.0.10.0/24'
+        with self.network() as net:
+            with self.subnet(net, cidr=cidr) as snet:
+                net_id = net['network']['id']
+                data = [{'network_id': net_id,
+                         'fixed_ips': [{'subnet_id': snet['subnet']['id'],
+                                        'ip_address': '10.0.10.100'}],
+                         'tenant_id': snet['subnet']['tenant_id']
+                         },
+                        {'network_id': net_id,
+                         'fixed_ips': [{'subnet_id': snet['subnet']['id'],
+                                        'ip_address': '10.0.20.101'}],
+                         'tenant_id': snet['subnet']['tenant_id']
+                         }]
+                res = self._create_bulk_from_list(self.fmt, 'port',
+                                                  data, as_admin=True)
+                self.assertEqual(webob.exc.HTTPBadRequest.code, res.status_int)
+                self.assertIn('IP address 10.0.20.101 is not a valid IP for '
+                              'the specified subnet.',
+                              res.json['NeutronError']['message'])
+
+                ipam_driver = driver.Pool.get_instance(None, self.context)
+                ipam_allocator = ipam_driver.get_allocator([cidr])
+                with db_api.CONTEXT_READER.using(self.context):
+                    ipam_subnet = ipam_allocator._driver.get_subnet(
+                        snet['subnet']['id'])
+                    allocations = ipam_subnet.subnet_manager.list_allocations(
+                        self.context)
+                    # There are no leftovers (e.g.: 10.0.10.100) in the
+                    # "IpamAllocation" registers
+                    self.assertEqual([], allocations)
+
     def test_delete_port_no_notify_in_disassociate_floatingips(self):
         ctx = context.get_admin_context()
         plugin = directory.get_plugin()

releasenotes/notes/port_bulk_creation_no_ipamallocation_leftovers-9d72cc5f616f51e4.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    During the port bulk creation, if an IPAM allocation fails (for example, if
+    the IP address is outside of the subnet CIDR), the other IPAM allocations
+    already created are deleted before raising the exception. Fixes bug
+    `2039550 <https://launchpad.net/bugs/2039550>`_.