From 70593c5d69e7953ad5d4a6f6d7483b4881b29d2f Mon Sep 17 00:00:00 2001
From: Thomas Herve <therve@redhat.com>
Date: Wed, 4 Nov 2015 10:52:59 +0100
Subject: [PATCH] Add caching to neutron extensions

This adds a oslo.cache option for neutron extensions, and enable cache
in integration tests.

Change-Id: Ibbdc210dd57c3559f87789854b6b9b9159694cf2
Closes-Bug: #1512771
---
 heat/common/cache.py                   | 18 ++++++++++++++++++
 heat/engine/clients/os/neutron.py      | 16 ++++++++++++++--
 heat_integrationtests/pre_test_hook.sh |  2 ++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/heat/common/cache.py b/heat/common/cache.py
index 7a348104e3..c8baaa7bd4 100644
--- a/heat/common/cache.py
+++ b/heat/common/cache.py
@@ -54,6 +54,24 @@ def register_cache_configurations(conf):
     conf.register_group(constraint_cache_group)
     conf.register_opts(constraint_cache_opts, group=constraint_cache_group)
 
+    extension_cache_group = cfg.OptGroup('service_extension_cache')
+    extension_cache_opts = [
+        cfg.IntOpt('expiration_time', default=3600,
+                   help=_(
+                       'TTL, in seconds, for any cached item in the '
+                       'dogpile.cache region used for caching of service '
+                       'extensions.')),
+        cfg.BoolOpt('caching', default=True,
+                    help=_(
+                        'Toggle to enable/disable caching when Orchestration '
+                        'Engine retrieves extensions from other OpenStack '
+                        'services. Please note that the global toggle for '
+                        'oslo.cache(enabled=True in [cache] group) must be '
+                        'enabled to use this feature.'))
+    ]
+    conf.register_group(extension_cache_group)
+    conf.register_opts(extension_cache_opts, group=extension_cache_group)
+
     return conf
 
 
diff --git a/heat/engine/clients/os/neutron.py b/heat/engine/clients/os/neutron.py
index 86ba81e562..9703feb24c 100644
--- a/heat/engine/clients/os/neutron.py
+++ b/heat/engine/clients/os/neutron.py
@@ -14,13 +14,21 @@
 from neutronclient.common import exceptions
 from neutronclient.neutron import v2_0 as neutronV20
 from neutronclient.v2_0 import client as nc
+from oslo_cache import core
+from oslo_config import cfg
 from oslo_utils import uuidutils
 
+from heat.common import cache
 from heat.common import exception
 from heat.engine.clients import client_plugin
 from heat.engine import constraints
 
 
+MEMOIZE = core.get_memoization_decorator(conf=cfg.CONF,
+                                         region=cache.get_cache_region(),
+                                         group="service_extension_cache")
+
+
 class NeutronClientPlugin(client_plugin.ClientPlugin):
 
     exceptions_module = exceptions
@@ -72,10 +80,14 @@ class NeutronClientPlugin(client_plugin.ClientPlugin):
         return neutronV20.find_resourceid_by_name_or_id(
             self.client(), key_type, props.get(key))
 
+    @MEMOIZE
+    def _list_extensions(self):
+        extensions = self.client().list_extensions().get('extensions')
+        return set(extension.get('alias') for extension in extensions)
+
     def has_extension(self, alias):
         """Check if specific extension is present."""
-        extensions = self.client().list_extensions().get('extensions')
-        return alias in [extension.get('alias') for extension in extensions]
+        return alias in self._list_extensions()
 
     def _resolve(self, props, key, id_key, key_type):
         if props.get(key):
diff --git a/heat_integrationtests/pre_test_hook.sh b/heat_integrationtests/pre_test_hook.sh
index 0de1c37ae4..21663f7be6 100755
--- a/heat_integrationtests/pre_test_hook.sh
+++ b/heat_integrationtests/pre_test_hook.sh
@@ -34,3 +34,5 @@ echo -e 'encrypt_parameters_and_properties=True\n' >> $localconf
 echo -e '[heat_api]\nworkers=1\n' >> $localconf
 echo -e '[heat_api_cfn]\nworkers=1\n' >> $localconf
 echo -e '[heat_api_cloudwatch]\nworkers=1\n' >> $localconf
+
+echo -e '[cache]\nenabled=True\n' >> $localconf