Add cached_zone to the amphora record

This will enable a number of possible features that need to select
amphorae based on their availability zone.

This would allow for quick-lookups on large lists and could be stale,
but it would be expected that future code that uses this would check
with nova for an update if it needs fully accurate data.

Having it be explicitly "cached" should take care of concerns about
users (operators, in this case) being confused about correctness.
Using simply the word "zone" should address concerns about commonality
between compute providers.

Change-Id: I8e26f99bca3496a454ba7bae2570f517e07d5fc2
Story: 2001221
Task: 5732

api-ref/source/parameters.yaml

@@ -185,6 +185,14 @@ bytes_out:
   in: body
   required: true
   type: integer
+cached-zone:
+  description: |
+    The availability zone of a compute instance, cached at create time. This
+    is not guaranteed to be current. May be an empty-string if the compute
+    service does not use zones.
+  in: body
+  required: true
+  type: string
 cert-busy:
   description: |
     Whether the certificate is in the process of being replaced.

api-ref/source/v2/amphora.inc

@@ -16,6 +16,12 @@ by using query string parameters. For information, see :ref:`filtering`.
 
 The list might be empty.
 
+.. NOTE::
+
+    The field `cached_zone` should be used for quick filtering and reference
+    only, as it may out of date. If an up-to-date zone is vital, we recommend
+    retrieving details directly from the compute service.
+
 .. rest_status_code:: success ../http-status.yaml
 
    - 200
@@ -60,6 +66,7 @@ Response Parameters
    - vrrp_interface: vrrp-interface
    - vrrp_id: vrrp-id
    - vrrp_priority: vrrp-priority
+   - cached_zone: cached-zone
 
 Response Example
 ----------------
@@ -79,6 +86,12 @@ If you are not an administrative user, the service returns the HTTP
 
 This operation does not require a request body.
 
+.. NOTE::
+
+    The field `cached_zone` should be used for quick filtering and reference
+    only, as it may out of date. If an up-to-date zone is vital, we recommend
+    retrieving details directly from the compute service.
+
 .. rest_status_code:: success ../http-status.yaml
 
    - 200
@@ -124,6 +137,7 @@ Response Parameters
    - vrrp_interface: vrrp-interface
    - vrrp_id: vrrp-id
    - vrrp_priority: vrrp-priority
+   - cached_zone: cached-zone
 
 Response Example
 ----------------

api-ref/source/v2/examples/amphora-list-response.json

@@ -15,7 +15,8 @@
             "status": "ALLOCATED",
             "vrrp_interface": "eth1",
             "vrrp_id": 1,
-            "vrrp_priority": 100
+            "vrrp_priority": 100,
+            "cached_zone": "zone1"
         },
         {
             "id": "89c186a3-cb16-497b-b099-c4bd40316642",
@@ -32,7 +33,8 @@
             "status": "ALLOCATED",
             "vrrp_interface": "eth1",
             "vrrp_id": 1,
-            "vrrp_priority": 200
+            "vrrp_priority": 200,
+            "cached_zone": "zone2"
         }
     ]
-}
+}

api-ref/source/v2/examples/amphora-show-response.json

@@ -14,6 +14,7 @@
         "status": "ALLOCATED",
         "vrrp_interface": "eth1",
         "vrrp_id": 1,
-        "vrrp_priority": 100
+        "vrrp_priority": 100,
+        "cached_zone": "zone1"
     }
-}
+}

octavia/api/v2/types/amphora.py

@@ -39,6 +39,7 @@ class AmphoraResponse(BaseAmphoraType):
     vrrp_interface = wtypes.wsattr(wtypes.StringType())
     vrrp_id = wtypes.wsattr(wtypes.IntegerType())
     vrrp_priority = wtypes.wsattr(wtypes.IntegerType())
+    cached_zone = wtypes.wsattr(wtypes.StringType())
 
     @classmethod
     def from_data_model(cls, data_model, children=False):

octavia/common/data_models.py

@@ -488,7 +488,7 @@ class Amphora(BaseDataModel):
                  ha_ip=None, vrrp_port_id=None, ha_port_id=None,
                  load_balancer=None, role=None, cert_expiration=None,
                  cert_busy=False, vrrp_interface=None, vrrp_id=None,
-                 vrrp_priority=None):
+                 vrrp_priority=None, cached_zone=None):
         self.id = id
         self.load_balancer_id = load_balancer_id
         self.compute_id = compute_id
@@ -505,6 +505,7 @@ class Amphora(BaseDataModel):
         self.load_balancer = load_balancer
         self.cert_expiration = cert_expiration
         self.cert_busy = cert_busy
+        self.cached_zone = cached_zone
 
     def delete(self):
         for amphora in self.load_balancer.amphorae:

octavia/compute/drivers/nova_driver.py

@@ -214,6 +214,7 @@ class VirtualMachineManager(compute_base.ComputeBase):
         # fields
 
         lb_network_ip = None
+        availability_zone = None
         fault = None
 
         try:
@@ -229,6 +230,12 @@ class VirtualMachineManager(compute_base.ComputeBase):
                 if is_boot_network or no_boot_networks:
                     lb_network_ip = interface.fixed_ips[0]['ip_address']
                     break
+            try:
+                availability_zone = getattr(
+                    nova_response, 'OS-EXT-AZ:availability_zone')
+            except AttributeError:
+                LOG.info('No availability zone listed for server %s',
+                         nova_response.id)
             fault = getattr(nova_response, 'fault', None)
         except Exception:
             LOG.debug('Extracting virtual interfaces through nova '
@@ -237,7 +244,8 @@ class VirtualMachineManager(compute_base.ComputeBase):
         response = models.Amphora(
             compute_id=nova_response.id,
             status=nova_response.status,
-            lb_network_ip=lb_network_ip
+            lb_network_ip=lb_network_ip,
+            cached_zone=availability_zone
         )
         return response, fault
 

octavia/controller/worker/tasks/database_tasks.py

@@ -872,8 +872,10 @@ class UpdateAmphoraInfo(BaseDatabaseTask):
         :param compute_obj: Compute on which an amphora resides
         :returns: Updated amphora object
         """
-        self.amphora_repo.update(db_apis.get_session(), amphora_id,
-                                 lb_network_ip=compute_obj.lb_network_ip)
+        self.amphora_repo.update(
+            db_apis.get_session(), amphora_id,
+            lb_network_ip=compute_obj.lb_network_ip,
+            cached_zone=compute_obj.cached_zone)
         return self.amphora_repo.get(db_apis.get_session(), id=amphora_id)
 
 

octavia/db/migration/alembic_migrations/versions/bf171d0d91c3_amphora_add_cached_zone.py

@@ -0,0 +1,33 @@
+#    Copyright 2017 GoDaddy
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""add cached_zone to amphora
+
+Revision ID: bf171d0d91c3
+Revises: 4aeb9e23ad43
+Create Date: 2017-10-06 12:07:34.290451
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = 'bf171d0d91c3'
+down_revision = '4aeb9e23ad43'
+
+
+def upgrade():
+    op.add_column(u'amphora', sa.Column(u'cached_zone', sa.String(255),
+                                        nullable=True))

octavia/db/models.py

@@ -511,6 +511,7 @@ class Amphora(base_models.BASE, base_models.IdMixin):
     vrrp_interface = sa.Column(sa.String(16), nullable=True)
     vrrp_id = sa.Column(sa.Integer(), nullable=True)
     vrrp_priority = sa.Column(sa.Integer(), nullable=True)
+    cached_zone = sa.Column(sa.String(255), nullable=True)
 
 
 class AmphoraHealth(base_models.BASE):

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

@@ -52,6 +52,7 @@ class TestAmphora(base.BaseAPITest):
             'vrrp_interface': 'eth1',
             'vrrp_id': 1,
             'vrrp_priority': 100,
+            'cached_zone': None
         }
         self.amp = self.amphora_repo.create(self.session, **self.amp_args)
         self.amp_id = self.amp.id

octavia/tests/functional/db/test_models.py

@@ -29,6 +29,7 @@ class ModelTestMixin(object):
     FAKE_IP = '10.0.0.1'
     FAKE_UUID_1 = uuidutils.generate_uuid()
     FAKE_UUID_2 = uuidutils.generate_uuid()
+    FAKE_AZ = 'zone1'
 
     def _insert(self, session, model_cls, model_kwargs):
         with session.begin():
@@ -138,7 +139,8 @@ class ModelTestMixin(object):
                   'ha_port_id': self.FAKE_UUID_2,
                   'lb_network_ip': self.FAKE_IP,
                   'cert_expiration': datetime.datetime.utcnow(),
-                  'cert_busy': False}
+                  'cert_busy': False,
+                  'cached_zone': self.FAKE_AZ}
         kwargs.update(overrides)
         return self._insert(session, models.Amphora, kwargs)
 

octavia/tests/unit/compute/drivers/test_nova_driver.py

@@ -107,6 +107,7 @@ class TestNovaClient(base.TestCase):
         self.nova_response.id = self.amphora.compute_id
         self.nova_response.status = 'ACTIVE'
         self.nova_response.fault = 'FAKE_FAULT'
+        setattr(self.nova_response, 'OS-EXT-AZ:availability_zone', None)
 
         self.interface_list = mock.MagicMock()
         self.interface_list.net_id = '1'
@@ -286,6 +287,13 @@ class TestNovaClient(base.TestCase):
         self.assertEqual(self.nova_response.fault, fault)
         self.nova_response.interface_list.called_with()
 
+    def test_translate_amphora_no_availability_zone(self):
+        delattr(self.nova_response, 'OS-EXT-AZ:availability_zone')
+        amphora, fault = self.manager._translate_amphora(self.nova_response)
+        self.assertEqual(self.amphora, amphora)
+        self.assertEqual(self.nova_response.fault, fault)
+        self.nova_response.interface_list.called_with()
+
     def test_bad_translate_amphora(self):
         self.nova_response.interface_list.side_effect = Exception
         self.manager._nova_client.networks.get.side_effect = Exception

releasenotes/notes/Add-cached_zone-to-the-amphora-record-7c3231c2b5b96574.yaml

@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    The compute zone (if applicable) is now cached in the database and returned
+    in the Amphora API as `cached_zone`. Please note that this is only set at
+    the original time of provisioning, and could be stale for various reasons
+    (for example, if live-migrations have taken place due to maintenances). We
+    recommend it be used for reference only, unless you are absolutey certain
+    it is current in your environment. The source of truth is still the system
+    you use for compute.