Don't create task db record during validation

Do not create database task record during 'rally task validate'
  command.

Change-Id: I1792b444aedcf2719b12708c221e317af6ac7e8c

rally/api.py

@@ -162,7 +162,7 @@ class Task(object):
         :param config: a dict with a task configuration
         """
         deployment = objects.Deployment.get(deployment)
-        task = objects.Task(deployment_uuid=deployment["uuid"])
+        task = objects.Task(deployment_uuid=deployment["uuid"], fake=True)
         benchmark_engine = engine.BenchmarkEngine(
             config, task, admin=deployment["admin"], users=deployment["users"])
         benchmark_engine.validate()

rally/objects/task.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import json
+import uuid
 
 from rally import consts
 from rally import db
@@ -106,11 +107,21 @@ TASK_RESULT_SCHEMA = {
 class Task(object):
     """Represents a task object."""
 
-    def __init__(self, task=None, **attributes):
-        if task:
-            self.task = task
+    def __init__(self, task=None, fake=False, **attributes):
+        """Task object init
+
+        :param task: dictionary like object, that represents a task
+        :param fake: if True, will be created task object with random UUID and
+            parameters, passed in 'attributes'. Does not create database
+            record. Used for special purposes, like task config validation.
+        """
+
+        self.fake = fake
+        if fake:
+            self.task = task or {"uuid": str(uuid.uuid4())}
+            self.task.update(attributes)
         else:
-            self.task = db.task_create(attributes)
+            self.task = task or db.task_create(attributes)
 
     def __getitem__(self, key):
         return self.task[key]
@@ -134,7 +145,8 @@ class Task(object):
         db.task_delete(uuid, status=status)
 
     def _update(self, values):
-        self.task = db.task_update(self.task["uuid"], values)
+        if not self.fake:
+            self.task = db.task_update(self.task["uuid"], values)
 
     def update_status(self, status):
         self._update({"status": status})

tests/unit/objects/test_task.py

@@ -47,6 +47,14 @@ class TaskTestCase(test.TestCase):
         self.assertFalse(mock_create.called)
         self.assertEqual(task["uuid"], self.task["uuid"])
 
+    @mock.patch("rally.objects.task.uuid.uuid4", return_value="some_uuid")
+    @mock.patch("rally.objects.task.db.task_create")
+    def test_init_with_fake_true(self, mock_create, mock_uuid):
+        task = objects.Task(fake=True)
+        self.assertFalse(mock_create.called)
+        self.assertTrue(mock_uuid.called)
+        self.assertEqual(task["uuid"], mock_uuid.return_value)
+
     @mock.patch("rally.objects.task.db.task_get")
     def test_get(self, mock_get):
         mock_get.return_value = self.task

tests/unit/test_api.py

@@ -69,6 +69,7 @@ class TaskAPITestCase(test.TestCase):
         ])
 
         mock_task.assert_called_once_with(
+            fake=True,
             deployment_uuid=mock_deployment_get.return_value["uuid"])
         mock_deployment_get.assert_called_once_with(
             mock_deployment_get.return_value["uuid"])