Switch to Subnet OVO in ipam_backend_mixin _save_subnet method

This patch switch to use Subnet OVO in
ipam_backend_mixin.IpamBackendMixin._save_subnet
method.

To use Subnet OVO there, additional changes in _make_subnet_args()
method are also required. Now this method returns:
* 'project_id' instead of 'tenant_id',
* 'cidr' as instance of netaddr.IPNetwork,
* 'gateway_ip' as instance of netaddr.IPAddress

Change-Id: I9fb284e98394b1a41ec8af919b65dc512663ff6a
Partially-Implements: blueprint adopt-oslo-versioned-objects-for-db

neutron/db/db_base_plugin_common.py

@@ -308,16 +308,15 @@ class DbBasePluginCommon(common_db_mixin.CommonDbMixin):
         return False
 
     def _make_subnet_args(self, detail, subnet, subnetpool_id):
-        gateway_ip = str(detail.gateway_ip) if detail.gateway_ip else None
-        args = {'tenant_id': detail.tenant_id,
+        args = {'project_id': detail.tenant_id,
                 'id': detail.subnet_id,
                 'name': subnet['name'],
                 'network_id': subnet['network_id'],
                 'ip_version': subnet['ip_version'],
-                'cidr': str(detail.subnet_cidr),
+                'cidr': detail.subnet_cidr,
                 'subnetpool_id': subnetpool_id,
                 'enable_dhcp': subnet['enable_dhcp'],
-                'gateway_ip': gateway_ip,
+                'gateway_ip': detail.gateway_ip,
                 'description': subnet.get('description')}
         if subnet['ip_version'] == 6 and subnet['enable_dhcp']:
             if validators.is_attr_set(subnet['ipv6_ra_mode']):

neutron/db/ipam_backend_mixin.py

@@ -24,7 +24,6 @@ from neutron_lib.api import validators
 from neutron_lib import constants as const
 from neutron_lib import exceptions as exc
 from oslo_config import cfg
-from oslo_db import exception as db_exc
 from oslo_log import log as logging
 from sqlalchemy import and_, or_
 from sqlalchemy.orm import exc as orm_exc
@@ -508,13 +507,20 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
 
         service_types = subnet_args.pop('service_types', [])
 
-        subnet = models_v2.Subnet(**subnet_args)
         segment_id = subnet_args.get('segment_id')
-        try:
-            context.session.add(subnet)
-            context.session.flush()
-        except db_exc.DBReferenceError:
-            raise segment_exc.SegmentNotFound(segment_id=segment_id)
+        if segment_id:
+            # TODO(slaweq): integrate check if segment exists in
+            # self._validate_segment() method
+            segment = network_obj.NetworkSegment.get_object(context,
+                                                            id=segment_id)
+            if not segment:
+                raise segment_exc.SegmentNotFound(segment_id=segment_id)
+
+        subnet = subnet_obj.Subnet(context, **subnet_args)
+        subnet.create()
+        # TODO(slaweq): when check is segment exists will be integrated in
+        # self._validate_segment() method, it should be moved to be done before
+        # subnet object is created
         self._validate_segment(context, network['id'], segment_id)
 
         # NOTE(changzhi) Store DNS nameservers with order into DB one
@@ -546,7 +552,7 @@ class IpamBackendMixin(db_base_plugin_common.DbBasePluginCommon):
         self.save_allocation_pools(context, subnet,
                                    subnet_request.allocation_pools)
 
-        return subnet
+        return subnet_obj.Subnet.get_object(context, id=subnet.id)
 
     def _classify_subnets(self, context, subnets):
         """Split into v4, v6 stateless and v6 stateful subnets"""

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

@@ -17,6 +17,7 @@ import functools
 
 import fixtures
 import mock
+import netaddr
 from neutron_lib.api.definitions import availability_zone as az_def
 from neutron_lib.api.definitions import external_net as extnet_apidef
 from neutron_lib.api.definitions import portbindings
@@ -2588,9 +2589,9 @@ class TestML2PluggableIPAM(test_ipam.UseIpamMixin, TestMl2SubnetsV2):
         with mock.patch(driver) as driver_mock:
             request = mock.Mock()
             request.subnet_id = uuidutils.generate_uuid()
-            request.subnet_cidr = cidr
+            request.subnet_cidr = netaddr.IPNetwork(cidr)
             request.allocation_pools = []
-            request.gateway_ip = gateway_ip
+            request.gateway_ip = netaddr.IPAddress(gateway_ip)
             request.tenant_id = uuidutils.generate_uuid()
 
             ipam_subnet = mock.Mock()