neutron: retrieve physical network name from a multi-provider network

Multi-provider networks are a combination of vxlan and vlan networks.
such a network has a special "segments" field that holds a list
of networks. Each element of this list has the same structure as the 'provider
network attributes'.
These attributes are:
- provider:network_type
- provider:physical_network
- provider:segmentation_id

This patch will retrieve the relevant physical network name from a
multi-provider network

Change-Id: Icb9a546e6fcbf399fcef3e9ea686b35ec3817cd5
Closes-Bug: #1659467

nova/network/neutronv2/api.py

@@ -1019,6 +1019,10 @@ class API(base_api.NetworkAPI):
             self._refresh_neutron_extensions_cache(context, neutron=neutron)
         return constants.AUTO_ALLOCATE_TOPO_EXT in self.extensions
 
+    def _has_multi_provider_extension(self, context, neutron=None):
+        self._refresh_neutron_extensions_cache(context, neutron=neutron)
+        return constants.MULTI_NET_EXT in self.extensions
+
     def _get_pci_device_profile(self, pci_dev):
         dev_spec = self.pci_whitelist.get_devspec(pci_dev)
         if dev_spec:
@@ -1402,6 +1406,37 @@ class API(base_api.NetworkAPI):
         raise exception.FixedIpNotFoundForSpecificInstance(
                 instance_uuid=instance.uuid, ip=address)
 
+    def _get_phynet_info(self, context, neutron, net_id):
+        phynet_name = None
+        if self._has_multi_provider_extension(context, neutron=neutron):
+            network = neutron.show_network(net_id,
+                                           fields='segments').get('network')
+            segments = network.get('segments', {})
+            for net in segments:
+                # NOTE(vladikr): In general, "multi-segments" network is a
+                # combination of L2 segments. The current implementation
+                # contains a vxlan and vlan(s) segments, where only a vlan
+                # network will have a physical_network specified, but may
+                # change in the future. The purpose of this method
+                # is to find a first segment that provides a physical network.
+                # TODO(vladikr): Additional work will be required to handle the
+                # case of multiple vlan segments associated with different
+                # physical networks.
+                phynet_name = net.get('provider:physical_network')
+                if phynet_name:
+                    return phynet_name
+            # Raising here as at least one segment should
+            # have a physical network provided.
+            if segments:
+                msg = (_("None of the segments of network %s provides a "
+                         "physical_network") % net_id)
+                raise exception.NovaException(message=msg)
+
+        net = neutron.show_network(net_id,
+                        fields='provider:physical_network').get('network')
+        phynet_name = net.get('provider:physical_network')
+        return phynet_name
+
     def _get_port_vnic_info(self, context, neutron, port_id):
         """Retrieve port vnic info
 
@@ -1415,9 +1450,7 @@ class API(base_api.NetworkAPI):
                              network_model.VNIC_TYPE_NORMAL)
         if vnic_type in network_model.VNIC_TYPES_SRIOV:
             net_id = port['network_id']
-            net = neutron.show_network(net_id,
+            phynet_name = self._get_phynet_info(context, neutron, net_id)
-                fields='provider:physical_network').get('network')
-            phynet_name = net.get('provider:physical_network')
         return vnic_type, phynet_name
 
     def create_pci_requests_for_sriov_ports(self, context, pci_requests,

nova/network/neutronv2/constants.py

@@ -19,3 +19,4 @@ PORTBINDING_EXT = 'Port Binding'
 VNIC_INDEX_EXT = 'VNIC Index'
 DNS_INTEGRATION = 'DNS Integration'
 AUTO_ALLOCATE_TOPO_EXT = 'Auto Allocated Topology Services'
+MULTI_NET_EXT = 'Multi Provider Network'

nova/tests/unit/network/test_neutronv2.py

@@ -3139,6 +3139,98 @@ class TestNeutronv2(TestNeutronv2Base):
         self.assertEqual(0, len(networks))
 
     @mock.patch.object(neutronapi, 'get_client', return_value=mock.Mock())
+    def test_get_port_vnic_info_multi_segment(self, mock_get_client):
+        api = neutronapi.API()
+        self.mox.ResetAll()
+        test_port = {
+            'port': {'id': 'my_port_id1',
+                      'network_id': 'net-id',
+                      'binding:vnic_type': model.VNIC_TYPE_DIRECT,
+                     },
+            }
+        test_net = {'network': {'segments':
+                                    [{'provider:physical_network': 'phynet10',
+                                      'provider:segmentation_id': 1000,
+                                      'provider:network_type': 'vlan'},
+                                     {'provider:physical_network': None,
+                                      'provider:segmentation_id': 153,
+                                      'provider:network_type': 'vxlan'}]}}
+        test_ext_list = {'extensions':
+                            [{'name': 'Multi Provider Network',
+                             'alias': 'multi-segments'}]}
+
+        mock_client = mock_get_client()
+        mock_client.show_port.return_value = test_port
+        mock_client.list_extensions.return_value = test_ext_list
+        mock_client.show_network.return_value = test_net
+        vnic_type, phynet_name = api._get_port_vnic_info(
+            self.context, mock_client, test_port['port']['id'])
+
+        mock_client.show_network.assert_called_once_with(
+            test_port['port']['network_id'],
+            fields='segments')
+        self.assertEqual('phynet10', phynet_name)
+
+    @mock.patch.object(neutronapi, 'get_client', return_value=mock.Mock())
+    def test_get_port_vnic_info_vlan_with_multi_segment_ext(self,
+                                                            mock_get_client):
+        api = neutronapi.API()
+        self.mox.ResetAll()
+        test_port = {
+            'port': {'id': 'my_port_id1',
+                      'network_id': 'net-id',
+                      'binding:vnic_type': model.VNIC_TYPE_DIRECT,
+                     },
+            }
+        test_net = {'network': {'provider:physical_network': 'phynet10',
+                                'provider:segmentation_id': 1000,
+                                'provider:network_type': 'vlan'}}
+        test_ext_list = {'extensions':
+                            [{'name': 'Multi Provider Network',
+                             'alias': 'multi-segments'}]}
+
+        mock_client = mock_get_client()
+        mock_client.show_port.return_value = test_port
+        mock_client.list_extensions.return_value = test_ext_list
+        mock_client.show_network.return_value = test_net
+        vnic_type, phynet_name = api._get_port_vnic_info(
+            self.context, mock_client, test_port['port']['id'])
+
+        mock_client.show_network.assert_called_with(
+            test_port['port']['network_id'],
+            fields='provider:physical_network')
+        self.assertEqual('phynet10', phynet_name)
+
+    @mock.patch.object(neutronapi, 'get_client', return_value=mock.Mock())
+    def test_get_port_vnic_info_multi_segment_no_phynet(self, mock_get_client):
+        api = neutronapi.API()
+        self.mox.ResetAll()
+        test_port = {
+            'port': {'id': 'my_port_id1',
+                      'network_id': 'net-id',
+                      'binding:vnic_type': model.VNIC_TYPE_DIRECT,
+                     },
+            }
+        test_net = {'network': {'segments':
+                                    [{'provider:physical_network': None,
+                                      'provider:segmentation_id': 1000,
+                                      'provider:network_type': 'vlan'},
+                                     {'provider:physical_network': None,
+                                      'provider:segmentation_id': 153,
+                                      'provider:network_type': 'vlan'}]}}
+        test_ext_list = {'extensions':
+                            [{'name': 'Multi Provider Network',
+                             'alias': 'multi-segments'}]}
+
+        mock_client = mock_get_client()
+        mock_client.show_port.return_value = test_port
+        mock_client.list_extensions.return_value = test_ext_list
+        mock_client.show_network.return_value = test_net
+        self.assertRaises(exception.NovaException,
+                          api._get_port_vnic_info,
+                          self.context, mock_client, test_port['port']['id'])
+
+    @mock.patch.object(neutronapi, 'get_client', return_value=mock.MagicMock())
     def test_get_port_vnic_info_1(self, mock_get_client):
         api = neutronapi.API()
         self.mox.ResetAll()

releasenotes/notes/retrieve_physical_network_from_multi-segment-eec5a490c1ed8739.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - Physical network name will be retrieved from a multi-segement network.
+    The current implementation will retrieve the physical network name for the
+    first segment that provides it. This is mostly intended to support a
+    combinatin of vxlan and vlan segments. Additional work will be required to
+    support a case of multiple vlan segments associated with different
+    physical networks.