Update network metadata type field for IPv6

Currently it is not possible to decide from looking at the network
metadata whether an IPv6 subnet is using slaac, dhcpv6-stateless or
dhcpv6-stateful.

So we add ipv6_address_mode information into the subnet metadata when
it is available and use that to construct the subnet type.

As a result, the type for a subnet with mode SLAAC will be "ipv6_slaac"
instead of "ipv6_dhcp" and similarly for the other available modes.

Change-Id: I751200a354ec9be2bfd5f94d3e4bbf53dab2c8bb
Partial-Bug: 1676363

nova/network/neutronv2/api.py

@@ -2259,6 +2259,8 @@ class API(base_api.NetworkAPI):
                                 address=subnet['gateway_ip'],
                                 type='gateway'),
             }
+            if subnet.get('ipv6_address_mode'):
+                subnet_dict['ipv6_address_mode'] = subnet['ipv6_address_mode']
 
             # attempt to populate DHCP server field
             search_opts = {'network_id': subnet['network_id'],

nova/tests/unit/network/test_network_info.py

@@ -963,6 +963,46 @@ class TestNetworkMetadata(test.NoDBTestCase):
             },
             net_metadata['networks'][1])
 
+    def _test_get_network_metadata_json_ipv6_addr_mode(self, mode):
+        ipv6_subnet = fake_network_cache_model.new_subnet(
+            subnet_dict=dict(dhcp_server='1234:567::',
+                             ipv6_address_mode=mode), version=6)
+
+        self.netinfo[0]['network']['subnets'][1] = ipv6_subnet
+        net_metadata = netutils.get_network_metadata(self.netinfo)
+
+        self.assertEqual(
+            {
+                'id': 'network1',
+                'link': 'interface0',
+                'ip_address': 'fd00::2',
+                'netmask': 'ffff:ffff:ffff::',
+                'routes': [
+                    {
+                        'network': '::',
+                        'netmask': '::',
+                        'gateway': 'fd00::1'
+                    },
+                    {
+                        'network': '::',
+                        'netmask': 'ffff:ffff:ffff::',
+                        'gateway': 'fd00::1:1'
+                    }
+                ],
+                'type': 'ipv6_%s' % mode,
+                'network_id': 1
+            },
+            net_metadata['networks'][1])
+
+    def test_get_network_metadata_json_ipv6_addr_mode_slaac(self):
+        self._test_get_network_metadata_json_ipv6_addr_mode('slaac')
+
+    def test_get_network_metadata_json_ipv6_addr_mode_stateful(self):
+        self._test_get_network_metadata_json_ipv6_addr_mode('dhcpv6-stateful')
+
+    def test_get_network_metadata_json_ipv6_addr_mode_stateless(self):
+        self._test_get_network_metadata_json_ipv6_addr_mode('dhcpv6-stateless')
+
     def test__get_nets(self):
         expected_net = {
             'id': 'network0',

nova/virt/netutils.py

@@ -261,7 +261,10 @@ def _get_nets(vif, subnet, version, net_num, link_id):
     :param link_id: Arbitrary identifier for the link the networks are
         attached to
     """
-    if subnet.get_meta('dhcp_server') is not None:
+    net_type = ''
+    if subnet.get_meta('ipv6_address_mode') is not None:
+        net_type = '_%s' % subnet.get_meta('ipv6_address_mode')
+    elif subnet.get_meta('dhcp_server') is not None:
         net_info = {
             'id': 'network%d' % net_num,
             'type': 'ipv%d_dhcp' % version,
@@ -279,7 +282,7 @@ def _get_nets(vif, subnet, version, net_num, link_id):
 
     net_info = {
         'id': 'network%d' % net_num,
-        'type': 'ipv%d' % version,
+        'type': 'ipv%d%s' % (version, net_type),
         'link': link_id,
         'ip_address': address,
         'netmask': netmask,

releasenotes/notes/added-network-metadata-7784295884f65c09.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    The network.json metadata format has been amended for IPv6 networks
+    under Neutron control. The type that is shown has been changed
+    from being always set to ``ipv6_dhcp`` to correctly reflecting the
+    ``ipv6_address_mode`` option in Neutron, so the type now will be
+    ``ipv6_slaac``, ``ipv6_dhcpv6-stateless`` or ``ipv6_dhcpv6-stateful``.
+upgrade:
+  - |
+    The information in the network.json metadata has been amended,
+    for IPv6 networks under Neutron control, the ``type`` field has been
+    changed from being always set to ``ipv6_dhcp`` to correctly reflecting
+    the ``ipv6_address_mode`` option in Neutron.