Simplify and optimize az server output extension.

Displaying two different az results to users is confusing, so just
return the az that the instance is actually in. Also, cache the
result from looking up the az by host for an hour to avoid making
lots of expensive db requests.

DocImpact

Change-Id: Ib39bf94c608874695aab00e61035e64f9594a985

10 files changed, 38 insertions, 39 deletions

diff --git a/nova/api/openstack/compute/contrib/extended_availability_zone.py b/nova/api/openstack/compute/contrib/extended_availability_zone.py
index b7451cb6a..734ddf7c8 100644
--- a/nova/api/openstack/compute/contrib/extended_availability_zone.py
+++ b/nova/api/openstack/compute/contrib/extended_availability_zone.py
@@ -21,26 +21,35 @@ from nova.api.openstack import extensions
 from nova.api.openstack import wsgi
 from nova.api.openstack import xmlutil
 from nova import availability_zones
+from nova.common import memorycache
 from nova.openstack.common import log as logging
 
 LOG = logging.getLogger(__name__)
+# NOTE(vish): azs don't change that often, so cache them for an hour to
+#             avoid hitting the db multiple times on every request.
+AZ_CACHE_SECONDS = 60 * 60
 authorize = extensions.soft_extension_authorizer('compute',
                                                  'extended_availability_zone')
 
 
 class ExtendedAZController(wsgi.Controller):
+    def __init__(self):
+        self.mc = memorycache.get_client()
 
     def _get_host_az(self, context, instance):
-        admin_context = context.elevated()
-        if instance['host']:
-            return availability_zones.get_host_availability_zone(
-                                            admin_context, instance['host'])
+        host = instance.get('host')
+        if not host:
+            return None
+        cache_key = "azcache-%s" % host
+        az = self.mc.get(cache_key)
+        if not az:
+            elevated = context.elevated()
+            az = availability_zones.get_host_availability_zone(elevated, host)
+            self.mc.set(cache_key, az, AZ_CACHE_SECONDS)
+        return az
 
     def _extend_server(self, context, server, instance):
         key = "%s:availability_zone" % Extended_availability_zone.alias
-        server[key] = instance.get('availability_zone', None)
-
-        key = "%s:host_availability_zone" % Extended_availability_zone.alias
         server[key] = self._get_host_az(context, instance)
 
     @wsgi.extends
@@ -81,10 +90,6 @@ class Extended_availability_zone(extensions.ExtensionDescriptor):
 def make_server(elem):
     elem.set('{%s}availability_zone' % Extended_availability_zone.namespace,
              '%s:availability_zone' % Extended_availability_zone.alias)
-    elem.set('{%s}host_availability_zone' %
-             Extended_availability_zone.namespace,
-             '%s:host_availability_zone' %
-             Extended_availability_zone.alias)
 
 
 class ExtendedAZTemplate(xmlutil.TemplateBuilder):
diff --git a/nova/tests/api/openstack/compute/contrib/test_extended_availability_zone.py b/nova/tests/api/openstack/compute/contrib/test_extended_availability_zone.py
index 8ebd810ac..d847e54f9 100644
--- a/nova/tests/api/openstack/compute/contrib/test_extended_availability_zone.py
+++ b/nova/tests/api/openstack/compute/contrib/test_extended_availability_zone.py
@@ -17,6 +17,7 @@ from lxml import etree
 import webob
 
 from nova.api.openstack.compute.contrib import extended_availability_zone
+from nova import availability_zones
 from nova import compute
 from nova import exception
 from nova.openstack.common import jsonutils
@@ -29,19 +30,20 @@ UUID3 = '00000000-0000-0000-0000-000000000003'
 
 
 def fake_compute_get(*args, **kwargs):
-    inst = fakes.stub_instance(1, uuid=UUID3, host="host-fake")
-    inst['availability_zone'] = 'az-i'
+    inst = fakes.stub_instance(1, uuid=UUID3, host="get-host")
     return inst
 
 
 def fake_compute_get_all(*args, **kwargs):
-    inst1 = fakes.stub_instance(1, uuid=UUID1, host="host-1")
-    inst2 = fakes.stub_instance(2, uuid=UUID2, host="host-2")
-    inst1['availability_zone'] = 'az-i'
-    inst2['availability_zone'] = 'az-i'
+    inst1 = fakes.stub_instance(1, uuid=UUID1, host="all-host")
+    inst2 = fakes.stub_instance(2, uuid=UUID2, host="all-host")
     return [inst1, inst2]
 
 
+def fake_get_host_availability_zone(context, host):
+    return host
+
+
 class ExtendedServerAttributesTest(test.TestCase):
     content_type = 'application/json'
     prefix = 'OS-EXT-AZ:'
@@ -51,6 +53,8 @@ class ExtendedServerAttributesTest(test.TestCase):
         fakes.stub_out_nw_api(self.stubs)
         self.stubs.Set(compute.api.API, 'get', fake_compute_get)
         self.stubs.Set(compute.api.API, 'get_all', fake_compute_get_all)
+        self.stubs.Set(availability_zones, 'get_host_availability_zone',
+                       fake_get_host_availability_zone)
 
         self.flags(
             osapi_compute_extension=[
@@ -69,20 +73,16 @@ class ExtendedServerAttributesTest(test.TestCase):
     def _get_servers(self, body):
         return jsonutils.loads(body).get('servers')
 
-    def assertServerAttributes(self, server, az_instance, az_host):
+    def assertServerAttributes(self, server, az):
         self.assertEqual(server.get('%savailability_zone' % self.prefix),
-                         az_instance)
-        self.assertEqual(server.get('%shost_availability_zone' % self.prefix),
-                         az_host)
+                         az)
 
     def test_show(self):
         url = '/v2/fake/servers/%s' % UUID3
         res = self._make_request(url)
 
         self.assertEqual(res.status_int, 200)
-        self.assertServerAttributes(self._get_server(res.body),
-                                    az_instance='az-i',
-                                    az_host='nova')
+        self.assertServerAttributes(self._get_server(res.body), 'get-host')
 
     def test_detail(self):
         url = '/v2/fake/servers/detail'
@@ -90,9 +90,7 @@ class ExtendedServerAttributesTest(test.TestCase):
 
         self.assertEqual(res.status_int, 200)
         for i, server in enumerate(self._get_servers(res.body)):
-            self.assertServerAttributes(server,
-                                        az_instance='az-i',
-                                        az_host='nova')
+            self.assertServerAttributes(server, 'all-host')
 
     def test_no_instance_passthrough_404(self):
 
diff --git a/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.json.tpl b/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.json.tpl
index 25915610d..413f3ce95 100644
--- a/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.json.tpl
+++ b/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.json.tpl
@@ -2,8 +2,7 @@
     "server": {
         "updated": "%(timestamp)s",
         "created": "%(timestamp)s",
-        "OS-EXT-AZ:availability_zone": null,
-        "OS-EXT-AZ:host_availability_zone": "nova",
+        "OS-EXT-AZ:availability_zone": "nova",
         "accessIPv4": "",
         "accessIPv6": "",
         "addresses": {
diff --git a/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.xml.tpl b/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.xml.tpl
index 1cdbd2012..849b9b750 100644
--- a/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.xml.tpl
+++ b/nova/tests/integrated/api_samples/OS-EXT-AZ/server-get-resp.xml.tpl
@@ -1,5 +1,5 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<server xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(uuid)s" OS-EXT-AZ:availability_zone="None" OS-EXT-AZ:host_availability_zone="nova">
+<server xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(uuid)s" OS-EXT-AZ:availability_zone="nova">
   <image id="%(uuid)s">
     <atom:link href="%(host)s/openstack/images/%(uuid)s" rel="bookmark"/>
   </image>
diff --git a/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.json.tpl b/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.json.tpl
index 895f0a514..362c85085 100644
--- a/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.json.tpl
+++ b/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.json.tpl
@@ -3,8 +3,7 @@
         {
             "updated": "%(timestamp)s",
             "created": "%(timestamp)s",
-            "OS-EXT-AZ:availability_zone": null,
-            "OS-EXT-AZ:host_availability_zone": "nova",
+            "OS-EXT-AZ:availability_zone": "nova",
             "accessIPv4": "",
             "accessIPv6": "",
             "addresses": {
diff --git a/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.xml.tpl b/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.xml.tpl
index 15cd9b1e1..9cd820cd0 100644
--- a/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.xml.tpl
+++ b/nova/tests/integrated/api_samples/OS-EXT-AZ/servers-detail-resp.xml.tpl
@@ -1,5 +1,5 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<servers xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1"> <server status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" OS-EXT-AZ:availability_zone="None" OS-EXT-AZ:host_availability_zone="nova">
+<servers xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1"> <server status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" OS-EXT-AZ:availability_zone="nova">
     <image id="%(uuid)s">
       <atom:link href="%(host)s/openstack/images/%(uuid)s" rel="bookmark"/>
     </image>
diff --git a/nova/tests/integrated/api_samples/all_extensions/server-get-resp.json.tpl b/nova/tests/integrated/api_samples/all_extensions/server-get-resp.json.tpl
index fefa37b4d..ccefc2dc7 100644
--- a/nova/tests/integrated/api_samples/all_extensions/server-get-resp.json.tpl
+++ b/nova/tests/integrated/api_samples/all_extensions/server-get-resp.json.tpl
@@ -1,8 +1,7 @@
 {
     "server": {
         "OS-DCF:diskConfig": "AUTO",
-        "OS-EXT-AZ:availability_zone": null,
-        "OS-EXT-AZ:host_availability_zone": "nova",
+        "OS-EXT-AZ:availability_zone": "nova",
         "OS-EXT-SRV-ATTR:host": "%(compute_host)s",
         "OS-EXT-SRV-ATTR:hypervisor_hostname": "%(hypervisor_hostname)s",
         "OS-EXT-SRV-ATTR:instance_name": "instance-00000001",
diff --git a/nova/tests/integrated/api_samples/all_extensions/server-get-resp.xml.tpl b/nova/tests/integrated/api_samples/all_extensions/server-get-resp.xml.tpl
index 4ba06b42e..973305854 100644
--- a/nova/tests/integrated/api_samples/all_extensions/server-get-resp.xml.tpl
+++ b/nova/tests/integrated/api_samples/all_extensions/server-get-resp.xml.tpl
@@ -1,5 +1,5 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<server xmlns:OS-DCF="http://docs.openstack.org/compute/ext/disk_config/api/v1.1" xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:OS-EXT-SRV-ATTR="http://docs.openstack.org/compute/ext/extended_status/api/v1.1"  xmlns:OS-EXT-IPS="http://docs.openstack.org/compute/ext/extended_ips/api/v1.1" xmlns:OS-EXT-STS="http://docs.openstack.org/compute/ext/extended_status/api/v1.1" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" key_name="None" config_drive="" OS-EXT-SRV-ATTR:vm_state="active" OS-EXT-SRV-ATTR:task_state="None" OS-EXT-SRV-ATTR:power_state="1" OS-EXT-SRV-ATTR:instance_name="instance-00000001" OS-EXT-SRV-ATTR:host="%(compute_host)s" OS-EXT-SRV-ATTR:hypervisor_hostname="%(hypervisor_hostname)s" OS-EXT-AZ:availability_zone="None" OS-EXT-AZ:host_availability_zone="nova" OS-DCF:diskConfig="AUTO">
+<server xmlns:OS-DCF="http://docs.openstack.org/compute/ext/disk_config/api/v1.1" xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:OS-EXT-SRV-ATTR="http://docs.openstack.org/compute/ext/extended_status/api/v1.1"  xmlns:OS-EXT-IPS="http://docs.openstack.org/compute/ext/extended_ips/api/v1.1" xmlns:OS-EXT-STS="http://docs.openstack.org/compute/ext/extended_status/api/v1.1" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" key_name="None" config_drive="" OS-EXT-SRV-ATTR:vm_state="active" OS-EXT-SRV-ATTR:task_state="None" OS-EXT-SRV-ATTR:power_state="1" OS-EXT-SRV-ATTR:instance_name="instance-00000001" OS-EXT-SRV-ATTR:host="%(compute_host)s" OS-EXT-SRV-ATTR:hypervisor_hostname="%(hypervisor_hostname)s" OS-EXT-AZ:availability_zone="nova" OS-DCF:diskConfig="AUTO">
   <image id="%(uuid)s">
     <atom:link href="%(host)s/openstack/images/%(uuid)s" rel="bookmark"/>
   </image>
diff --git a/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.json.tpl b/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.json.tpl
index 667ef6471..d50088837 100644
--- a/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.json.tpl
+++ b/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.json.tpl
@@ -2,8 +2,7 @@
     "servers": [
         {
             "OS-DCF:diskConfig": "AUTO",
-            "OS-EXT-AZ:availability_zone": null,
-            "OS-EXT-AZ:host_availability_zone": "nova",
+            "OS-EXT-AZ:availability_zone": "nova",
             "OS-EXT-SRV-ATTR:host": "%(compute_host)s",
             "OS-EXT-SRV-ATTR:hypervisor_hostname": "%(hypervisor_hostname)s",
             "OS-EXT-SRV-ATTR:instance_name": "instance-00000001",
diff --git a/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.xml.tpl b/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.xml.tpl
index 104c82bc5..e2166c2ff 100644
--- a/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.xml.tpl
+++ b/nova/tests/integrated/api_samples/all_extensions/servers-details-resp.xml.tpl
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='UTF-8'?>
 <servers xmlns:OS-DCF="http://docs.openstack.org/compute/ext/disk_config/api/v1.1" xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:OS-EXT-SRV-ATTR="http://docs.openstack.org/compute/ext/extended_status/api/v1.1"  xmlns:OS-EXT-IPS="http://docs.openstack.org/compute/ext/extended_ips/api/v1.1" xmlns:OS-EXT-STS="http://docs.openstack.org/compute/ext/extended_status/api/v1.1" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1">
-  <server xmlns:OS-DCF="http://docs.openstack.org/compute/ext/disk_config/api/v1.1" xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:OS-EXT-SRV-ATTR="http://docs.openstack.org/compute/ext/extended_status/api/v1.1"  xmlns:OS-EXT-IPS="http://docs.openstack.org/compute/ext/extended_ips/api/v1.1" xmlns:OS-EXT-STS="http://docs.openstack.org/compute/ext/extended_status/api/v1.1" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" key_name="None" config_drive="" OS-EXT-SRV-ATTR:vm_state="active" OS-EXT-SRV-ATTR:task_state="None" OS-EXT-SRV-ATTR:power_state="1" OS-EXT-SRV-ATTR:instance_name="instance-00000001" OS-EXT-SRV-ATTR:host="%(compute_host)s" OS-EXT-SRV-ATTR:hypervisor_hostname="%(hypervisor_hostname)s" OS-EXT-AZ:availability_zone="None" OS-EXT-AZ:host_availability_zone="nova" OS-DCF:diskConfig="AUTO">
+  <server xmlns:OS-DCF="http://docs.openstack.org/compute/ext/disk_config/api/v1.1" xmlns:OS-EXT-AZ="http://docs.openstack.org/compute/ext/extended_availability_zone/api/v2" xmlns:OS-EXT-SRV-ATTR="http://docs.openstack.org/compute/ext/extended_status/api/v1.1"  xmlns:OS-EXT-IPS="http://docs.openstack.org/compute/ext/extended_ips/api/v1.1" xmlns:OS-EXT-STS="http://docs.openstack.org/compute/ext/extended_status/api/v1.1" xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://docs.openstack.org/compute/api/v1.1" status="ACTIVE" updated="%(timestamp)s" hostId="%(hostid)s" name="new-server-test" created="%(timestamp)s" userId="fake" tenantId="openstack" accessIPv4="" accessIPv6="" progress="0" id="%(id)s" key_name="None" config_drive="" OS-EXT-SRV-ATTR:vm_state="active" OS-EXT-SRV-ATTR:task_state="None" OS-EXT-SRV-ATTR:power_state="1" OS-EXT-SRV-ATTR:instance_name="instance-00000001" OS-EXT-SRV-ATTR:host="%(compute_host)s" OS-EXT-SRV-ATTR:hypervisor_hostname="%(hypervisor_hostname)s" OS-EXT-AZ:availability_zone="nova" OS-DCF:diskConfig="AUTO">
     <image id="%(uuid)s">
       <atom:link href="%(host)s/openstack/images/%(uuid)s" rel="bookmark"/>
     </image>