Moved preprocess function from base to types

The preprocess function was moved from benchmark.runners
.base to benchmark.types. Decoupling the preprocess
function from base removes a dependency in code.

A unit test for preprocess has also been added to
test_types.py.

Change-Id: I311316c667bb6256ea5f0a32e24328102b62c6e8

rally/benchmark/runners/base.py

@@ -21,6 +21,7 @@ import jsonschema
 from oslo.config import cfg
 
 from rally.benchmark.scenarios import base as scenario_base
+from rally.benchmark import types
 from rally.benchmark import utils
 from rally import consts
 from rally import exceptions
@@ -209,7 +210,7 @@ class ScenarioRunner(object):
         cls = scenario_base.Scenario.get_by_name(cls_name)
 
         # NOTE(boris-42): processing @types decorators
-        args = cls.preprocess(method_name, context, args)
+        args = types.preprocess(cls, method_name, context, args)
 
         with rutils.Timer() as timer:
             self._run_scenario(cls, method_name, context, args)

rally/benchmark/scenarios/base.py

@@ -22,7 +22,6 @@ import time
 
 from rally import consts
 from rally import exceptions
-from rally import osclients
 from rally import utils
 
 
@@ -171,22 +170,6 @@ class Scenario(object):
         method = getattr(cls, method_name)
         return copy.deepcopy(getattr(method, attr_name, default))
 
-    @classmethod
-    def preprocess(cls, method_name, context, args):
-        """Run preprocessor on scenario arguments."""
-        preprocessors = Scenario.meta(cls, method_name=method_name,
-                                      attr_name="preprocessors", default={})
-        clients = osclients.Clients(context["admin"]["endpoint"])
-
-        for src, preprocessor in preprocessors.items():
-            resource_config = args.get(src)
-            if resource_config:
-                args[src] = preprocessor.transform(
-                                clients=clients,
-                                resource_config=resource_config)
-
-        return args
-
     def context(self):
         """Returns the context of the current benchmark scenario."""
         return self._context

rally/benchmark/types.py

@@ -14,10 +14,13 @@
 #    under the License.
 
 import abc
+import copy
 import operator
 import re
 
+from rally.benchmark.scenarios import base
 from rally import exceptions
+from rally import osclients
 
 
 def set(**kwargs):
@@ -34,6 +37,31 @@ def set(**kwargs):
     return wrapper
 
 
+def preprocess(cls, method_name, context, args):
+    """Run preprocessor on scenario arguments.
+
+    :param cls: class name of benchmark scenario
+    :param method_name: name of benchmark scenario method
+    :param context: dictionary object that must have admin and endpoint entries
+    :param args: args section of benchmark specification in rally task file
+
+    :returns processed_args: dictionary object with additional client
+                             and resource configuration
+
+    """
+    preprocessors = base.Scenario.meta(cls, method_name=method_name,
+                                       attr_name="preprocessors", default={})
+    clients = osclients.Clients(context["admin"]["endpoint"])
+    processed_args = copy.deepcopy(args)
+
+    for src, preprocessor in preprocessors.items():
+        resource_cfg = processed_args.get(src)
+        if resource_cfg:
+            processed_args[src] = preprocessor.transform(
+                clients=clients, resource_config=resource_cfg)
+    return processed_args
+
+
 class ResourceType(object):
 
     @classmethod

tests/benchmark/runners/test_base.py

@@ -241,8 +241,9 @@ class ScenarioRunnerTestCase(test.TestCase):
         cls_name, method_name = scenario_name.split(".", 1)
         cls = scenario_base.Scenario.get_by_name(cls_name)
 
+        expected_config_kwargs = {"image": 1, "flavor": 1}
         runner._run_scenario.assert_called_once_with(
-            cls, method_name, context_obj, config_kwargs)
+            cls, method_name, context_obj, expected_config_kwargs)
 
     def test_runner_send_result_exception(self):
         runner = serial.SerialScenarioRunner(

tests/benchmark/test_types.py

@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import mock
+
 from rally.benchmark import types
 from rally import exceptions
 from tests import fakes
@@ -165,3 +167,33 @@ class VolumeTypeResourceTypeTestCase(test.TestCase):
         self.assertRaises(exceptions.InvalidScenarioArgument,
                           types.VolumeTypeResourceType.transform,
                           self.clients, resource_config)
+
+
+class PreprocessTestCase(test.TestCase):
+
+    @mock.patch("rally.benchmark.types.base.Scenario.meta")
+    @mock.patch("rally.benchmark.types.osclients")
+    def test_preprocess(self, mock_osclients, mock_meta):
+        cls = "some_class"
+        method_name = "method_name"
+        context = {
+            "a": 1,
+            "b": 2,
+            "admin": {"endpoint": mock.MagicMock()}
+        }
+        args = {"a": 10, "b": 20}
+
+        class Preprocessor(types.ResourceType):
+
+            @classmethod
+            def transform(cls, clients, resource_config):
+                return resource_config * 2
+
+        mock_meta.return_value = {"a": Preprocessor}
+        result = types.preprocess(cls, method_name, context, args)
+        mock_meta.assert_called_once_with(cls, default={},
+                                          method_name=method_name,
+                                          attr_name="preprocessors")
+        mock_osclients.Clients.assert_called_once_with(
+            context["admin"]["endpoint"])
+        self.assertEqual({"a": 20, "b": 20}, result)