Fix subnet_key calculation

Two issues being fixed:
1. When subnet is added, we are adding an entry in kv-store to get
   the mapping from subnet uuid to key. In neutron backend, we
   calculate the key by converting prefix/len to IPNetwork and
   then converting it back to string values. While creating this
   mapping, we were directly using the supplied prefix and len.
   The former method could normalize ip v6 prefixes by stripping
   trailing 0 that may not be required. Fixed to use the same method
   in both places.
2. If subnet id is available, use it compare whenever possible to
   avoid the above issue.

Change-Id: Icee9fe8e77688427aa2fab415e059f7bdbd35e5d
Closes-Bug: 1596763
(cherry picked from commit 390287e)

src/config/vnc_openstack/vnc_openstack/__init__.py

@@ -879,7 +879,7 @@ def post_virtual_network_create(self, vn_dict):
                 prefix = subnet_dict['ip_prefix']
                 prefix_len = subnet_dict['ip_prefix_len']
                 network = IPNetwork('%s/%s' % (prefix, prefix_len))
-                subnet_name = vn_dict['uuid'] + ' ' + subnet_dict['ip_prefix'] + '/' + str(
+                subnet_name = vn_dict['uuid'] + ' ' + str(network.ip) + '/' + str(
                     subnet_dict['ip_prefix_len'])
                 subnet_uuid = ipam_subnet['subnet_uuid']
                 self._vnc_lib.kv_store(subnet_uuid, subnet_name)

src/config/vnc_openstack/vnc_openstack/neutron_plugin_db.py

@@ -1428,14 +1428,7 @@ def _subnet_vnc_to_neutron(self, subnet_vnc, net_obj, ipam_fq_name):
         sn_q_dict['cidr'] = cidr
         sn_q_dict['ip_version'] = IPNetwork(cidr).version # 4 or 6
 
-        # read from useragent kv only for old subnets created
-        # before schema had uuid in subnet
         sn_id = subnet_vnc.subnet_uuid
-        if not sn_id:
-            subnet_key = self._subnet_vnc_get_key(subnet_vnc, net_obj.uuid)
-            sn_id = self._subnet_vnc_read_mapping(id=subnet_vnc.subnet_uuid,
-                                                            key=subnet_key)
-
         sn_q_dict['id'] = sn_id
 
         sn_q_dict['gateway_ip'] = subnet_vnc.default_gateway
@@ -2222,8 +2215,7 @@ def _port_check_and_add_iface_route_table(self, fixed_ips, net_obj,
                 host_routes = subnet.get_host_routes()
                 if host_routes is None:
                     continue
-                subnet_key = self._subnet_vnc_get_key(subnet, net_obj.uuid)
-                sn_id = self._subnet_vnc_read_mapping(key=subnet_key)
+                sn_id = subnet.subnet_uuid
                 subnet_cidr = '%s/%s' % (subnet.subnet.get_ip_prefix(),
                                          subnet.subnet.get_ip_prefix_len())
 
@@ -2623,7 +2615,7 @@ def subnet_create(self, subnet_q):
         else:  # virtual-network already linked to this ipam
             for subnet in net_ipam_ref['attr'].get_ipam_subnets():
                 if subnet_key == self._subnet_vnc_get_key(subnet, net_id):
-                    existing_sn_id = self._subnet_vnc_read_mapping(key=subnet_key)
+                    existing_sn_id = subnet.subnet_uuid
                     # duplicate !!
                     msg = _("Cidr %s overlaps with another subnet of subnet %s"
                             ) % (subnet_q['cidr'], existing_sn_id)
@@ -2662,8 +2654,7 @@ def subnet_read(self, subnet_id):
             for ipam_ref in ipam_refs:
                 subnet_vncs = ipam_ref['attr'].get_ipam_subnets()
                 for subnet_vnc in subnet_vncs:
-                    if (self._subnet_vnc_get_key(subnet_vnc, net_id) ==
-                        subnet_key):
+                    if subnet_vnc.subnet_uuid == subnet_id:
                         ret_subnet_q = self._subnet_vnc_to_neutron(
                             subnet_vnc, net_obj, ipam_ref['to'])
                         return ret_subnet_q
@@ -2698,8 +2689,7 @@ def subnet_update(self, subnet_id, subnet_q):
             for ipam_ref in ipam_refs:
                 subnets = ipam_ref['attr'].get_ipam_subnets()
                 for subnet_vnc in subnets:
-                    if self._subnet_vnc_get_key(subnet_vnc,
-                               net_id) == subnet_key:
+                    if subnet_vnc.subnet_uuid == subnet_id:
                         subnet_found = True
                         break
                 if subnet_found:
@@ -2770,8 +2760,7 @@ def subnet_delete(self, subnet_id):
             for ipam_ref in ipam_refs:
                 orig_subnets = ipam_ref['attr'].get_ipam_subnets()
                 new_subnets = [subnet_vnc for subnet_vnc in orig_subnets
-                               if self._subnet_vnc_get_key(subnet_vnc,
-                               net_id) != subnet_key]
+                               if subnet_vnc.subnet_uuid != subnet_id]
                 if len(orig_subnets) != len(new_subnets):
                     # matched subnet to be deleted
                     ipam_ref['attr'].set_ipam_subnets(new_subnets)