Merge "Cache the description of RAID properties"

2 files changed, 44 insertions, 9 deletions

diff --git a/ironic/api/controllers/v1/driver.py b/ironic/api/controllers/v1/driver.py
index 855555218..d28376db9 100644
--- a/ironic/api/controllers/v1/driver.py
+++ b/ironic/api/controllers/v1/driver.py
@@ -47,6 +47,16 @@ _DRIVER_PROPERTIES = {}
 # versions, the API service should be restarted.
 _VENDOR_METHODS = {}
 
+# RAID (logical disk) configuration information for drivers:
+#   key = driver name;
+#   value = dictionary of RAID configuration information of that driver:
+#             key = property name.
+#             value = description of the property
+# NOTE(rloo). This is cached for the lifetime of the API service. If one or
+# more conductor services are restarted with new driver versions, the API
+# service should be restarted.
+_RAID_PROPERTIES = {}
+
 
 class Driver(base.APIBase):
     """API representation of a driver."""
@@ -171,15 +181,20 @@ class DriverRaidController(rest.RestController):
         """
         if not api_utils.allow_raid_config():
             raise exception.NotAcceptable()
-        topic = pecan.request.rpcapi.get_topic_for_driver(driver_name)
-        try:
-            return pecan.request.rpcapi.get_raid_logical_disk_properties(
-                pecan.request.context, driver_name, topic=topic)
-        except exception.UnsupportedDriverExtension as e:
-            # Change error code as 404 seems appropriate because RAID is a
-            # standard interface and all drivers might not have it.
-            e.code = http_client.NOT_FOUND
-            raise
+
+        if driver_name not in _RAID_PROPERTIES:
+            topic = pecan.request.rpcapi.get_topic_for_driver(driver_name)
+            try:
+                info = pecan.request.rpcapi.get_raid_logical_disk_properties(
+                    pecan.request.context, driver_name, topic=topic)
+            except exception.UnsupportedDriverExtension as e:
+                # Change error code as 404 seems appropriate because RAID is a
+                # standard interface and all drivers might not have it.
+                e.code = http_client.NOT_FOUND
+                raise
+
+            _RAID_PROPERTIES[driver_name] = info
+        return _RAID_PROPERTIES[driver_name]
 
 
 class DriversController(rest.RestController):
diff --git a/ironic/tests/api/v1/test_drivers.py b/ironic/tests/api/v1/test_drivers.py
index 13a227c68..1c47feb82 100644
--- a/ironic/tests/api/v1/test_drivers.py
+++ b/ironic/tests/api/v1/test_drivers.py
@@ -176,6 +176,7 @@ class TestListDrivers(base.FunctionalTest):
 
     @mock.patch.object(rpcapi.ConductorAPI, 'get_raid_logical_disk_properties')
     def test_raid_logical_disk_properties(self, disk_prop_mock):
+        driver._RAID_PROPERTIES = {}
         self.register_fake_conductors()
         properties = {'foo': 'description of foo'}
         disk_prop_mock.return_value = properties
@@ -188,6 +189,7 @@ class TestListDrivers(base.FunctionalTest):
 
     @mock.patch.object(rpcapi.ConductorAPI, 'get_raid_logical_disk_properties')
     def test_raid_logical_disk_properties_older_version(self, disk_prop_mock):
+        driver._RAID_PROPERTIES = {}
         self.register_fake_conductors()
         properties = {'foo': 'description of foo'}
         disk_prop_mock.return_value = properties
@@ -198,8 +200,26 @@ class TestListDrivers(base.FunctionalTest):
         self.assertEqual(406, ret.status_code)
 
     @mock.patch.object(rpcapi.ConductorAPI, 'get_raid_logical_disk_properties')
+    def test_raid_logical_disk_properties_cached(self, disk_prop_mock):
+        # only one RPC-conductor call will be made and the info cached
+        # for subsequent requests
+        driver._RAID_PROPERTIES = {}
+        self.register_fake_conductors()
+        properties = {'foo': 'description of foo'}
+        disk_prop_mock.return_value = properties
+        path = '/drivers/%s/raid/logical_disk_properties' % self.d1
+        for i in range(3):
+            data = self.get_json(path,
+                                 headers={api_base.Version.string: "1.12"})
+            self.assertEqual(properties, data)
+        disk_prop_mock.assert_called_once_with(mock.ANY, self.d1,
+                                               topic=mock.ANY)
+        self.assertEqual(properties, driver._RAID_PROPERTIES[self.d1])
+
+    @mock.patch.object(rpcapi.ConductorAPI, 'get_raid_logical_disk_properties')
     def test_raid_logical_disk_properties_iface_not_supported(
             self, disk_prop_mock):
+        driver._RAID_PROPERTIES = {}
         self.register_fake_conductors()
         disk_prop_mock.side_effect = iter(
             [exception.UnsupportedDriverExtension(