Add default-subnetpools to DFPlugin

default subnetpools is pure control plane functionality in neutron. df can
just enable it. And fullstack can use it to avoid subnet collisions.

TODO: should we remove all unintentional, explicit subnet cidr defination
in fullstack?

Change-Id: I32afc73c1cf289bdbfb51ea3c140aff903c7261b
Closes-Bug: #1562966

dragonflow/common/extensions.py

@@ -26,5 +26,6 @@ SUPPORTED_API_EXTENSIONS = [
     'subnet_allocation',
     'port-security',
     'allowed-address-pairs',
-    'net-mtu'
+    'net-mtu',
+    'default-subnetpools'
 ]

dragonflow/tests/fullstack/test_base.py

@@ -46,6 +46,12 @@ class DFTestBase(base.BaseTestCase):
              password=creds['password'], auth_url=auth_url,
              tenant_name=tenant_name)
         self.neutron.format = 'json'
+
+        # NOTE: Each env can only have one default subnetpool for each
+        # IP version.
+        if not self.get_default_subnetpool():
+            self.create_default_subnetpool()
+
         common_config.init(['--config-file', '/etc/neutron/neutron.conf'])
         self.conf = cfg.CONF.df
         self.integration_bridge = self.conf.integration_bridge
@@ -61,6 +67,25 @@ class DFTestBase(base.BaseTestCase):
         if cfg.CONF.df.enable_selective_topology_distribution:
             self.start_subscribing()
 
+    def get_default_subnetpool(self):
+        default_subnetpool = None
+        subnetpool_filter = {'is_default': True,
+                             'ip_version': 4}
+        subnetpools = self.neutron.list_subnetpools(
+            **subnetpool_filter).get('subnetpools')
+        if subnetpools:
+            default_subnetpool = subnetpools[0]
+
+        return default_subnetpool
+
+    def create_default_subnetpool(self):
+        default_subnetpool = {'prefixes': ['10.0.0.0/8'],
+                              'name': 'default_subnetpool_v4',
+                              'is_default': True,
+                              'default_prefixlen': 24}
+        self.neutron.create_subnetpool(
+            body={'subnetpool': default_subnetpool})
+
     def store(self, obj, close_func=None):
         close_func = close_func if close_func else obj.close
         self.__objects_to_close.append(close_func)

dragonflow/tests/fullstack/test_objects.py

@@ -312,7 +312,7 @@ class SubnetTestObj(object):
     def create(self, subnet=None):
         if not subnet:
             subnet = {
-                'cidr': '192.168.199.0/24',
+                'use_default_subnetpool': True,
                 'ip_version': 4,
                 'network_id': self.network_id
             }