Support creating from existing subnetpool

To use this feature, users need to pre-create the subnetpool and
pass the pool name to kuryr. For example:

$ docker network create -d kuryr --ipam-driver=kuryr ... \
    -o neutron.pool.name=testpool \
    --ipam-opt neutron.pool.name=testpool \
    foo

Kuryr will look for the existing subnetpool in neutron instead of
creating a new subnetpool. If the network is deleted, the existing
subnetpool will not be deleted.

NOTE: the option 'neutron.pool.name' was used to specify an custom
name of subnetpool. This commit will the semantic of this option.

Implements: blueprint existing-subnetpool
Change-Id: I73f6c17e0e941ef9dbd20591002fdf96c59e6424

kuryr_libnetwork/controllers.py

@@ -1280,7 +1280,6 @@ def ipam_request_pool():
                        "Another pool with same cidr exist. ipam and network"
                        " options not used to pass pool name")
 
-        if not pools:
             new_subnetpool = {
                 'name': pool_name,
                 'default_prefixlen': cidr.prefixlen,
@@ -1289,6 +1288,15 @@ def ipam_request_pool():
                 {'subnetpool': new_subnetpool})
             pool = created_subnetpool_response['subnetpool']
             pool_id = pool['id']
+        else:
+            existing_pools = _get_subnetpools_by_attrs(name=pool_name)
+            if not existing_pools:
+                raise exceptions.KuryrException(
+                    ("Specified subnetpool name({0}) does not "
+                    "exist.").format(pool_name))
+            pool_id = existing_pools[0]['id']
+            LOG.info(_LI("Using existing Neutron subnetpool %s successfully"),
+                     pool_id)
     else:
         if v6:
             default_pool_list = SUBNET_POOLS_V6
@@ -1500,6 +1508,15 @@ def ipam_release_pool():
             if pool_id in tmp_subnet.get('tags', []):
                 _neutron_subnet_remove_tag(tmp_subnet['id'], pool_id)
                 break
+
+    pools = _get_subnetpools_by_attrs(id=pool_id)
+    if pools:
+        pool_name = pools[0]['name']
+        if not pool_name.startswith(cfg.CONF.subnetpool_name_prefix):
+            LOG.debug('Skip the cleanup since this is an existing Neutron '
+                      'subnetpool.')
+            return flask.jsonify(const.SCHEMA['SUCCESS'])
+
     try:
         app.neutron.delete_subnetpool(pool_id)
     except n_exceptions.Conflict as ex:

kuryr_libnetwork/tests/unit/test_kuryr_ipam.py

@@ -112,22 +112,16 @@ class TestKuryrIpam(base.TestKuryrBase):
         decoded_json = jsonutils.loads(response.data)
         self.assertEqual(fake_kuryr_subnetpool_id, decoded_json['PoolID'])
 
-    @mock.patch('kuryr_libnetwork.controllers.app.neutron.create_subnetpool')
+    @mock.patch('kuryr_libnetwork.controllers.app.neutron.list_subnetpools')
     @mock.patch('kuryr_libnetwork.controllers.app.neutron.list_subnets')
     @ddt.data((FAKE_IP4_CIDR), (FAKE_IP6_CIDR))
     def test_ipam_driver_request_pool_with_pool_name_option(self,
-            pool_cidr, mock_list_subnets, mock_create_subnetpool):
+            pool_cidr, mock_list_subnets, mock_list_subnetpools):
         fake_subnet = {"subnets": []}
         mock_list_subnets.return_value = fake_subnet
 
         fake_kuryr_subnetpool_id = uuidutils.generate_uuid()
         fake_name = 'fake_pool_name'
-        prefixlen = ipaddress.ip_network(six.text_type(pool_cidr)).prefixlen
-        new_subnetpool = {
-            'name': fake_name,
-            'default_prefixlen': prefixlen,
-            'prefixes': [pool_cidr]}
-
         if pool_cidr == FAKE_IP4_CIDR:
             kuryr_subnetpools = self._get_fake_v4_subnetpools(
                 fake_kuryr_subnetpool_id, prefixes=[pool_cidr],
@@ -136,17 +130,13 @@ class TestKuryrIpam(base.TestKuryrBase):
             kuryr_subnetpools = self._get_fake_v6_subnetpools(
                 fake_kuryr_subnetpool_id, prefixes=[pool_cidr],
                 name=fake_name)
-        fake_subnetpool_response = {
-            'subnetpool': kuryr_subnetpools['subnetpools'][0]
-        }
-
-        mock_create_subnetpool.return_value = fake_subnetpool_response
+        mock_list_subnetpools.return_value = kuryr_subnetpools
 
         fake_request = {
             'AddressSpace': '',
             'Pool': pool_cidr,
             'SubPool': pool_cidr,
-            'Options': {'neutron.pool.name': 'fake_pool_name'},
+            'Options': {'neutron.pool.name': fake_name},
             'V6': False
         }
         response = self.app.post('/IpamDriver.RequestPool',
@@ -155,8 +145,6 @@ class TestKuryrIpam(base.TestKuryrBase):
 
         self.assertEqual(200, response.status_code)
         mock_list_subnets.assert_called_with(cidr=pool_cidr)
-        mock_create_subnetpool.assert_called_with(
-            {'subnetpool': new_subnetpool})
         decoded_json = jsonutils.loads(response.data)
         self.assertEqual(fake_kuryr_subnetpool_id, decoded_json['PoolID'])
 
@@ -243,6 +231,54 @@ class TestKuryrIpam(base.TestKuryrBase):
                                                fake_kuryr_subnetpool_id)
         mock_delete_subnetpool.assert_called_with(fake_kuryr_subnetpool_id)
 
+    @mock.patch('kuryr_libnetwork.controllers.app.neutron.remove_tag')
+    @mock.patch('kuryr_libnetwork.controllers.app.neutron.list_subnets')
+    @mock.patch('kuryr_libnetwork.controllers.app.neutron.list_subnetpools')
+    @mock.patch('kuryr_libnetwork.controllers.app')
+    @ddt.data((True), (False))
+    def test_ipam_driver_release_pool_with_pool_name_option(
+            self, use_tag_ext, mock_app, mock_list_subnetpools,
+            mock_list_subnets, mock_remove_tag):
+        mock_app.tag_ext = use_tag_ext
+
+        fake_kuryr_subnetpool_id = uuidutils.generate_uuid()
+        fake_subnetpool_name = 'fake_pool_name'
+        kuryr_subnetpools = self._get_fake_v4_subnetpools(
+            fake_kuryr_subnetpool_id, prefixes=[FAKE_IP4_CIDR],
+            name=fake_subnetpool_name)
+        mock_list_subnetpools.return_value = kuryr_subnetpools
+
+        docker_endpoint_id = lib_utils.get_hash()
+        neutron_network_id = uuidutils.generate_uuid()
+        subnet_v4_id = uuidutils.generate_uuid()
+        fake_v4_subnet = self._get_fake_v4_subnet(
+            neutron_network_id, docker_endpoint_id, subnet_v4_id,
+            subnetpool_id=fake_kuryr_subnetpool_id,
+            cidr=FAKE_IP4_CIDR)
+        fake_subnet_response = {
+            'subnets': [
+                fake_v4_subnet['subnet']
+            ]
+        }
+        mock_list_subnets.return_value = fake_subnet_response
+
+        fake_request = {
+            'PoolID': fake_kuryr_subnetpool_id
+        }
+        response = self.app.post('/IpamDriver.ReleasePool',
+                                content_type='application/json',
+                                data=jsonutils.dumps(fake_request))
+
+        self.assertEqual(200, response.status_code)
+        if mock_app.tag_ext:
+            mock_list_subnetpools.assert_called_with(
+                id=fake_kuryr_subnetpool_id)
+            mock_list_subnets.assert_called_with(
+                cidr=FAKE_IP4_CIDR)
+            mock_remove_tag.assert_called_with('subnets',
+                                               subnet_v4_id,
+                                               fake_kuryr_subnetpool_id)
+
     @mock.patch('kuryr_libnetwork.controllers._neutron_port_add_tag')
     @mock.patch('kuryr_libnetwork.controllers.app.neutron.create_port')
     @mock.patch('kuryr_libnetwork.controllers.app.neutron.list_subnets')

releasenotes/notes/bp-existing-subnetpool-aa454cf843cba47c.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    Support creating a Docker network with existing subnetpool. Users can use
+    the option "neutron.pool.name" to specify the name of existing neutron
+    subnetpool.
+upgrade:
+  - |
+    The semantic of the option "neutron.pool.name" is changed. This option was
+    used to specify a custom name of the creating subnetpool, and now it is
+    used to specify the name of a pre-existing subnetpool. As a result,
+    subnetpools created with custom name in before are now treated as external
+    resources and won't be cleanup on deletion. Users need to cleanup the
+    resources manually.