loadbalancer vip-network-id IP availability check

The existing code selects the first IPv4 subnet in the network without
any consideration of ip availability.  If not enough IPs are available,
the loadbalancer creations fails.  This patch uses neutron ip
availability API to check the quantity of free IPs when creating
loadbalancer with vip-network-id and skips subnets that do not have
enough IPs for a loadbalancer on multi subnet networks.

Change-Id: If3c3cf9be085bb95b4ebbaf71e24f92d42b8d6e0
Task: 36004
Story: 2006293

octavia/api/v2/controllers/load_balancer.py

@@ -136,9 +136,29 @@ class LoadBalancersController(base.BaseController):
                         "VIP address specified."
                     ))
             else:
-                # If subnet and IP are not provided, pick the first subnet,
-                # preferring ipv4
-                for subnet_id in network.subnets:
+                # If subnet and IP are not provided, pick the first subnet with
+                # enough available IPs, preferring ipv4
+                if not network.subnets:
+                    raise exceptions.ValidationException(detail=_(
+                        "Supplied network does not contain a subnet."
+                    ))
+                ip_avail = network_driver.get_network_ip_availability(
+                    network)
+                if (CONF.controller_worker.loadbalancer_topology ==
+                        constants.TOPOLOGY_SINGLE):
+                    num_req_ips = 2
+                if (CONF.controller_worker.loadbalancer_topology ==
+                        constants.TOPOLOGY_ACTIVE_STANDBY):
+                    num_req_ips = 3
+                subnets = [subnet_id for subnet_id in network.subnets if
+                           utils.subnet_ip_availability(ip_avail, subnet_id,
+                                                        num_req_ips)]
+                if not subnets:
+                    raise exceptions.ValidationException(detail=_(
+                        "Subnet(s) in the supplied network do not contain "
+                        "enough available IPs."
+                    ))
+                for subnet_id in subnets:
                     # Use the first subnet, in case there are no ipv4 subnets
                     if not load_balancer.vip_subnet_id:
                         load_balancer.vip_subnet_id = subnet_id
@@ -146,10 +166,6 @@ class LoadBalancersController(base.BaseController):
                     if subnet.ip_version == 4:
                         load_balancer.vip_subnet_id = subnet_id
                         break
-                if not load_balancer.vip_subnet_id:
-                    raise exceptions.ValidationException(detail=_(
-                        "Supplied network does not contain a subnet."
-                    ))
 
     @staticmethod
     def _validate_port_and_fill_or_validate_subnet(load_balancer):

octavia/common/utils.py

@@ -110,6 +110,13 @@ def get_six_compatible_server_certs_key_passphrase():
     return base64.urlsafe_b64encode(key)
 
 
+def subnet_ip_availability(nw_ip_avail, subnet_id, req_num_ips):
+    for subnet in nw_ip_avail.subnet_ip_availability:
+        if subnet['subnet_id'] == subnet_id:
+            return subnet['total_ips'] - subnet['used_ips'] >= req_num_ips
+    return None
+
+
 class exception_logger(object):
     """Wrap a function and log raised exception
 

octavia/network/base.py

@@ -336,3 +336,12 @@ class AbstractNetworkDriver(object):
 
         :return: Boolean
         """
+
+    @abc.abstractmethod
+    def get_network_ip_availability(self, network):
+        """Retrieves network IP availability.
+
+        :param network: octavia.network.data_models.Network
+        :return: octavia.network.data_models.Network_IP_Availability
+        :raises: NetworkException, NetworkNotFound
+        """

octavia/network/data_models.py

@@ -149,3 +149,17 @@ class HostRoute(data_models.BaseDataModel):
 class QosPolicy(data_models.BaseDataModel):
     def __init__(self, id):
         self.id = id
+
+
+class Network_IP_Availability(data_models.BaseDataModel):
+
+    def __init__(self, network_id=None, tenant_id=None, project_id=None,
+                 network_name=None, total_ips=None, used_ips=None,
+                 subnet_ip_availability=None):
+        self.network_id = network_id
+        self.tenant_id = tenant_id
+        self.project_id = project_id
+        self.network_name = network_name
+        self.total_ips = total_ips
+        self.used_ips = used_ips
+        self.subnet_ip_availability = subnet_ip_availability

octavia/network/drivers/neutron/base.py

@@ -256,3 +256,6 @@ class BaseNeutronDriver(base.AbstractNetworkDriver):
 
     def qos_enabled(self):
         return self._qos_enabled
+
+    def get_network_ip_availability(self, network):
+        return self._get_resource('network_ip_availability', network.id)

octavia/network/drivers/neutron/utils.py

@@ -94,3 +94,12 @@ def convert_floatingip_dict_to_model(floating_ip_dict):
         fixed_ip_address=floating_ip.get('fixed_ip_address'),
         fixed_port_id=floating_ip.get('fixed_port_id')
     )
+
+
+def convert_network_ip_availability_dict_to_model(
+        network_ip_availability_dict):
+    nw_ip_avail = network_ip_availability_dict.get(
+        'network_ip_availability', network_ip_availability_dict)
+    ip_avail = network_models.Network_IP_Availability.from_dict(nw_ip_avail)
+    ip_avail.subnet_ip_availability = nw_ip_avail.get('subnet_ip_availability')
+    return ip_avail

octavia/network/drivers/noop_driver/driver.py

@@ -264,6 +264,21 @@ class NoopManager(object):
     def qos_enabled(self):
         return self._qos_extension_enabled
 
+    def get_network_ip_availability(self, network):
+        LOG.debug("Network %s no-op, network_ip_availability network_id %s",
+                  self.__class__.__name__, network.id)
+        self.networkconfigconfig[(network.id, 'ip_availability')] = (
+            network.id, 'get_network_ip_availability')
+        ip_avail = network_models.Network_IP_Availability(
+            network_id=network.id)
+        subnet_ip_availability = []
+        network.subnets = list(network.subnets)
+        for subnet_id in network.subnets:
+            subnet_ip_availability.append({'subnet_id': subnet_id,
+                                          'used_ips': 0, 'total_ips': 254})
+        ip_avail.subnet_ip_availability = subnet_ip_availability
+        return ip_avail
+
 
 class NoopNetworkDriver(driver_base.AbstractNetworkDriver):
     def __init__(self):
@@ -345,3 +360,6 @@ class NoopNetworkDriver(driver_base.AbstractNetworkDriver):
 
     def qos_enabled(self):
         return self.driver.qos_enabled()
+
+    def get_network_ip_availability(self, network):
+        return self.driver.get_network_ip_availability(network)

octavia/tests/common/constants.py

@@ -198,3 +198,19 @@ MOCK_VRRP_PORT2 = {'port': {'network_id': MOCK_VIP_NET_ID,
                             'device_owner': MOCK_DEVICE_OWNER,
                             'id': MOCK_VRRP_PORT_ID2,
                             'fixed_ips': MOCK_VRRP_FIXED_IPS2}}
+
+MOCK_NETWORK_TOTAL_IPS = 254
+MOCK_NETWORK_USED_IPS = 0
+MOCK_SUBNET_TOTAL_IPS = 254
+MOCK_SUBNET_USED_IPS = 0
+MOCK_SUBNET_IP_AVAILABILITY = [{'used_ips': MOCK_SUBNET_USED_IPS,
+                                'subnet_id': MOCK_SUBNET_ID,
+                                'total_ips': MOCK_SUBNET_TOTAL_IPS}]
+
+MOCK_NETWORK_IP_AVAILABILITY = {'network_ip_availability': (
+    {'network_id': MOCK_NETWORK_ID,
+     'tenant_id': MOCK_PROJECT_ID,
+     'network_name': MOCK_NETWORK_NAME,
+     'total_ips': MOCK_NETWORK_TOTAL_IPS,
+     'used_ips': MOCK_NETWORK_USED_IPS,
+     'subnet_ip_availability': MOCK_SUBNET_IP_AVAILABILITY})}

octavia/tests/functional/api/v2/test_load_balancer.py

@@ -225,6 +225,89 @@ class TestLoadBalancer(base.BaseAPITest):
         self.assertEqual(subnet.id, api_lb.get('vip_subnet_id'))
         self.assertEqual(network_id, api_lb.get('vip_network_id'))
 
+    def test_create_with_vip_network_picks_subnet_ipv4_avail_ips(self):
+        self.conf.config(
+            group='controller_worker',
+            loadbalancer_topology=constants.TOPOLOGY_ACTIVE_STANDBY)
+        network_id = uuidutils.generate_uuid()
+        subnet1 = network_models.Subnet(id=uuidutils.generate_uuid(),
+                                        network_id=network_id,
+                                        ip_version=4)
+        subnet2 = network_models.Subnet(id=uuidutils.generate_uuid(),
+                                        network_id=network_id,
+                                        ip_version=4)
+        subnet3 = network_models.Subnet(id=uuidutils.generate_uuid(),
+                                        network_id=network_id,
+                                        ip_version=4)
+        network = network_models.Network(id=network_id,
+                                         subnets=[subnet1.id, subnet2.id,
+                                                  subnet3.id])
+        subnet_ip_availability = [{'subnet_id': subnet1.id, 'used_ips': 254,
+                                  'total_ips': 254}, {'subnet_id': subnet2.id,
+                                  'used_ips': 128, 'total_ips': 254},
+                                  {'subnet_id': subnet3.id, 'used_ips': 254,
+                                  'total_ips': 254}]
+        ip_avail = network_models.Network_IP_Availability(
+            network_id=network.id,
+            subnet_ip_availability=subnet_ip_availability)
+        lb_json = {'vip_network_id': network.id,
+                   'project_id': self.project_id}
+        body = self._build_body(lb_json)
+        with mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_network") as mock_get_network, mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_subnet") as mock_get_subnet, mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_network_ip_availability") as (
+                mock_get_network_ip_availability):
+            mock_get_network.return_value = network
+            mock_get_subnet.side_effect = [subnet1, subnet2, subnet3]
+            mock_get_network_ip_availability.return_value = ip_avail
+            response = self.post(self.LBS_PATH, body)
+        api_lb = response.json.get(self.root_tag)
+        self._assert_request_matches_response(lb_json, api_lb)
+        self.assertEqual(subnet2.id, api_lb.get('vip_subnet_id'))
+        self.assertEqual(network_id, api_lb.get('vip_network_id'))
+
+    def test_create_with_vip_network_not_enough_avail_ips(self):
+        self.conf.config(
+            group='controller_worker',
+            loadbalancer_topology=constants.TOPOLOGY_ACTIVE_STANDBY)
+        network_id = uuidutils.generate_uuid()
+        subnet1 = network_models.Subnet(id=uuidutils.generate_uuid(),
+                                        network_id=network_id,
+                                        ip_version=4)
+        subnet2 = network_models.Subnet(id=uuidutils.generate_uuid(),
+                                        network_id=network_id,
+                                        ip_version=4)
+        network = network_models.Network(id=network_id,
+                                         subnets=[subnet1.id, subnet2.id])
+        subnet_ip_availability = [{'subnet_id': subnet1.id, 'used_ips': 254,
+                                  'total_ips': 254}, {'subnet_id': subnet2.id,
+                                  'used_ips': 254, 'total_ips': 254}]
+        ip_avail = network_models.Network_IP_Availability(
+            network_id=network.id,
+            subnet_ip_availability=subnet_ip_availability)
+        lb_json = {'vip_network_id': network.id,
+                   'project_id': self.project_id}
+        body = self._build_body(lb_json)
+        with mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_network") as mock_get_network, mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_subnet") as mock_get_subnet, mock.patch(
+            "octavia.network.drivers.noop_driver.driver.NoopManager"
+            ".get_network_ip_availability") as (
+                mock_get_network_ip_availability):
+            mock_get_network.return_value = network
+            mock_get_subnet.side_effect = [subnet1, subnet2]
+            mock_get_network_ip_availability.return_value = ip_avail
+            response = self.post(self.LBS_PATH, body, status=400)
+        err_msg = ('Validation failure: Subnet(s) in the supplied network do '
+                   'not contain enough available IPs.')
+        self.assertEqual(err_msg, response.json.get('faultstring'))
+
     def test_create_with_vip_network_and_address(self):
         ip_address = '198.51.100.10'
         network_id = uuidutils.generate_uuid()

octavia/tests/unit/network/drivers/neutron/test_base.py

@@ -481,3 +481,18 @@ class TestBaseNeutronNetworkDriver(base.TestCase):
                           self.driver.apply_qos_on_port,
                           t_constants.MOCK_PORT_ID,
                           t_constants.MOCK_NEUTRON_QOS_POLICY_ID)
+
+    def test_get_network_ip_availability(self):
+        show_network_ip_availability = (
+            self.driver.neutron_client.show_network_ip_availability)
+        show_network_ip_availability.return_value = (
+            {'network_ip_availability': {
+             'network_id': t_constants.MOCK_NETWORK_ID,
+             'subnet_ip_availability': t_constants.MOCK_SUBNET_IP_AVAILABILITY
+             }})
+        ip_avail = self.driver.get_network_ip_availability(
+            network_models.Network(t_constants.MOCK_NETWORK_ID))
+        self.assertIsInstance(ip_avail, network_models.Network_IP_Availability)
+        self.assertEqual(t_constants.MOCK_NETWORK_ID, ip_avail.network_id)
+        self.assertEqual(t_constants.MOCK_SUBNET_IP_AVAILABILITY,
+                         ip_avail.subnet_ip_availability)

octavia/tests/unit/network/drivers/neutron/test_utils.py

@@ -117,3 +117,17 @@ class TestNeutronUtils(base.TestCase):
             fixed_port_id=t_constants.MOCK_PORT_ID2
         )
         self._compare_ignore_value_none(model_obj.to_dict(), assert_dict)
+
+    def test_convert_network_ip_availability_dict_to_model(self):
+        model_obj = utils.convert_network_ip_availability_dict_to_model(
+            t_constants.MOCK_NETWORK_IP_AVAILABILITY)
+        assert_dict = dict(
+            network_id=t_constants.MOCK_NETWORK_ID,
+            tenant_id=t_constants.MOCK_PROJECT_ID,
+            network_name=t_constants.MOCK_NETWORK_NAME,
+            total_ips=t_constants.MOCK_NETWORK_TOTAL_IPS,
+            used_ips=t_constants.MOCK_NETWORK_USED_IPS,
+            subnet_ip_availability=t_constants.MOCK_SUBNET_IP_AVAILABILITY
+        )
+        self._compare_ignore_value_none(model_obj.to_dict(recurse=True),
+                                        assert_dict)

releasenotes/notes/fix-vip-network-ip-availability-2e924f32abf01052.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixes an issue in the selection of vip-subnet-id on multi-subnet networks
+    by checking the IP availability of the subnets, ensuring enough IPs are
+    available for loadbalancer when creating loadbalancer specifying
+    vip-network-id.