Make sure that there's a way of creating a subnet without a gateway

Fixes bug 1028646
You can use null for gateway ip.

Change-Id: I969112ad46efa22203db40106d4e35dce1757165

quantum/api/v2/attributes.py

@@ -66,6 +66,12 @@ def _validate_ip_address(data, valid_values=None):
         return msg
 
 
+def _validate_ip_address_or_none(data, valid_values=None):
+    if data is None:
+        return None
+    return _validate_ip_address(data, valid_values)
+
+
 def _validate_subnet(data, valid_values=None):
     try:
         netaddr.IPNetwork(data)
@@ -103,7 +109,6 @@ def convert_to_boolean(data):
     msg = _("%s is not boolean") % data
     raise q_exc.InvalidInput(error_message=msg)
 
-
 HEX_ELEM = '[0-9A-Fa-f]'
 UUID_PATTERN = '-'.join([HEX_ELEM + '{8}', HEX_ELEM + '{4}',
                          HEX_ELEM + '{4}', HEX_ELEM + '{4}',
@@ -117,6 +122,7 @@ def convert_to_boolean(data):
               'type:values': _validate_values,
               'type:mac_address': _validate_mac_address,
               'type:ip_address': _validate_ip_address,
+              'type:ip_address_or_none': _validate_ip_address_or_none,
               'type:subnet': _validate_subnet,
               'type:regex': _validate_regex}
 
@@ -226,7 +232,7 @@ def convert_to_boolean(data):
                  'is_visible': True},
         'gateway_ip': {'allow_post': True, 'allow_put': True,
                        'default': ATTR_NOT_SPECIFIED,
-                       'validate': {'type:ip_address': None},
+                       'validate': {'type:ip_address_or_none': None},
                        'is_visible': True},
         #TODO(salvatore-orlando): Enable PUT on allocation_pools
         'allocation_pools': {'allow_post': True, 'allow_put': False,

quantum/db/db_base_plugin_v2.py

@@ -566,8 +566,9 @@ def _validate_allocation_pools(self, ip_pools, gateway_ip, subnet_cidr):
                   "and gateway ip")
         ip_ranges = ip_pools[:]
         # Treat gw as IPset as well
-        ip_ranges.append(gateway_ip)
-        ip_sets.append(netaddr.IPSet([gateway_ip]))
+        if gateway_ip:
+            ip_ranges.append(gateway_ip)
+            ip_sets.append(netaddr.IPSet([gateway_ip]))
         # Use integer cursors as an efficient way for implementing
         # comparison and avoiding comparing the same pair twice
         for l_cursor in range(len(ip_sets)):
@@ -593,11 +594,12 @@ def _allocate_pools_for_subnet(self, context, subnet):
 
         pools = []
         if subnet['allocation_pools'] == attributes.ATTR_NOT_SPECIFIED:
-            # Auto allocate the pool around gateway
-            gw_ip = int(netaddr.IPAddress(subnet['gateway_ip']))
+            # Auto allocate the pool around gateway_ip
             net = netaddr.IPNetwork(subnet['cidr'])
             first_ip = net.first + 1
             last_ip = net.last - 1
+            gw_ip = int(netaddr.IPAddress(subnet['gateway_ip'] or net.last))
+
             if gw_ip > first_ip:
                 pools.append({'start': str(netaddr.IPAddress(first_ip)),
                               'end': str(netaddr.IPAddress(gw_ip - 1))})
@@ -657,6 +659,8 @@ def _make_subnet_dict(self, subnet, fields=None):
                                     for pool in subnet['allocation_pools']],
                'gateway_ip': subnet['gateway_ip'],
                'enable_dhcp': subnet['enable_dhcp']}
+        if subnet['gateway_ip']:
+            res['gateway_ip'] = subnet['gateway_ip']
         return self._fields(res, fields)
 
     def _make_port_dict(self, port, fields=None):

quantum/tests/unit/test_db_plugin.py

@@ -22,6 +22,8 @@
 import webob.exc
 
 import quantum
+from quantum.api.v2 import attributes
+from quantum.api.v2.attributes import ATTR_NOT_SPECIFIED
 from quantum.api.v2.router import APIRouter
 from quantum.common import config
 from quantum.common import exceptions as q_exc
@@ -140,12 +142,16 @@ def _create_subnet(self, fmt, net_id, cidr,
                            'cidr': cidr,
                            'ip_version': 4,
                            'tenant_id': self._tenant_id}}
-        for arg in ('gateway_ip', 'allocation_pools',
+        for arg in ('allocation_pools',
                     'ip_version', 'tenant_id',
                     'enable_dhcp'):
             # Arg must be present and not null (but can be false)
             if arg in kwargs and kwargs[arg] is not None:
                 data['subnet'][arg] = kwargs[arg]
+
+        if kwargs.get('gateway_ip', ATTR_NOT_SPECIFIED) != ATTR_NOT_SPECIFIED:
+            data['subnet']['gateway_ip'] = kwargs['gateway_ip']
+
         subnet_req = self.new_create_request('subnets', data, fmt)
         if (kwargs.get('set_context') and 'tenant_id' in kwargs):
             # create a specific auth context for this request
@@ -241,7 +247,7 @@ def network(self, name='net1',
 
     @contextlib.contextmanager
     def subnet(self, network=None,
-               gateway_ip=None,
+               gateway_ip=ATTR_NOT_SPECIFIED,
                cidr='10.0.0.0/24',
                fmt='json',
                ip_version=4,
@@ -725,7 +731,7 @@ def test_requested_subnet_id_v4_and_v6(self):
                                           net_id=net_id,
                                           cidr='2607:f0d0:1002:51::0/124',
                                           ip_version=6,
-                                          gateway_ip=None)
+                                          gateway_ip=ATTR_NOT_SPECIFIED)
                 subnet2 = self.deserialize(fmt, res)
                 kwargs = {"fixed_ips":
                           [{'subnet_id': subnet['subnet']['id']},
@@ -1220,6 +1226,27 @@ def test_create_subnet_with_allocation_pool(self):
                                  cidr=cidr,
                                  allocation_pools=allocation_pools)
 
+    def test_create_subnet_with_none_gateway(self):
+        cidr = '10.0.0.0/24'
+        self._test_create_subnet(gateway_ip=None,
+                                 cidr=cidr)
+
+    def test_create_subnet_with_none_gateway_fully_allocated(self):
+        cidr = '10.0.0.0/24'
+        allocation_pools = [{'start': '10.0.0.1',
+                             'end': '10.0.0.254'}]
+        self._test_create_subnet(gateway_ip=None,
+                                 cidr=cidr,
+                                 allocation_pools=allocation_pools)
+
+    def test_create_subnet_with_none_gateway_allocation_pool(self):
+        cidr = '10.0.0.0/24'
+        allocation_pools = [{'start': '10.0.0.2',
+                             'end': '10.0.0.100'}]
+        self._test_create_subnet(gateway_ip=None,
+                                 cidr=cidr,
+                                 allocation_pools=allocation_pools)
+
     def test_create_subnet_with_v6_allocation_pool(self):
         gateway_ip = 'fe80::1'
         cidr = 'fe80::0/80'