Display proper missing argument name

Find and show argument name instead of showing argument of 'dest'
Add functional test for this
Remove test_cli_utils.py -> utils.py because this actually utils,
not tests.

Change-Id: Icc138ecf40b4929826efcad52c135c8809348d20
Closes-Bug: #1380562

rally/cmd/cliutils.py

@@ -178,7 +178,12 @@ def run(argv, categories):
         # if you just got a single arg wrong.
         print(fn.__doc__)
         CONF.print_help()
-        print(e)
+        print("Missing arguments:")
+        for missing in e.missing:
+            for arg in fn.args:
+                if arg[1].get('dest', '').endswith(missing):
+                    print(" " + arg[0][0])
+                    break
         return(1)
     try:
         ret = fn(*fn_args, **fn_kwargs)

tests/functional/test_cli_deployment.py

@@ -13,12 +13,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-
 import json
 import unittest
 
 import mock
-import test_cli_utils as utils
+
+from tests.functional import utils
 
 
 class DeploymentTestCase(unittest.TestCase):

tests/functional/test_cli_info.py

@@ -16,7 +16,7 @@
 
 import unittest
 
-import test_cli_utils as utils
+from tests.functional import utils
 
 
 class InfoTestCase(unittest.TestCase):

tests/functional/test_cli_show.py

@@ -16,7 +16,7 @@
 
 import unittest
 
-import test_cli_utils as utils
+from tests.functional import utils
 
 
 class ShowTestCase(unittest.TestCase):

tests/functional/test_cli_task.py

@@ -13,12 +13,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-
 import os
 import unittest
 
 import mock
-import test_cli_utils as utils
+
+from tests.functional import utils
 
 
 class TaskTestCase(unittest.TestCase):

tests/functional/test_cli_use.py

@@ -0,0 +1,30 @@
+# Copyright 2014: Mirantis Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import unittest
+
+from tests.functional import utils
+
+
+class CliUtilsTestCase(unittest.TestCase):
+
+    def setUp(self):
+        super(CliUtilsTestCase, self).setUp()
+        self.rally = utils.Rally()
+
+    def test_missing_argument(self):
+        with self.assertRaises(utils.RallyCmdError) as e:
+            self.rally("use task")
+        self.assertIn("--uuid", e.exception.output)