Change TaskNotFound traceback info to user-friendly message

In some common cases (like detecting absense of requested object),
CLI shows exception traceback instead of just a simple message
that "<something> is not found".

This traceback is redundant and confusing users - they think that
rally went into trouble, but all that actually happened is wrong
uuid specified.

The traceback must be shown only with `--debug' option explicitly
specified.

The unit test and functional test are both provided.

Change-Id: I32811974d88f414c4508dfed19a7c5dc5e80fd98
Closes-Bug: #1392354

rally/cmd/cliutils.py

@@ -302,6 +302,11 @@ def run(argv, categories):
             raise
         print(e)
         return 1
+    except exceptions.TaskNotFound as e:
+        if CONF.debug:
+            LOG.exception(e)
+        print(e)
+        return 1
     except Exception:
         print(_("Command failed, please check log for more info"))
         raise

tests/functional/test_cli_task.py

@@ -21,6 +21,9 @@ import mock
 from tests.functional import utils
 
 
+FAKE_TASK_UUID = '87ab639d-4968-4638-b9a1-07774c32484a'
+
+
 class TaskTestCase(unittest.TestCase):
 
     def _get_sample_task_config(self):
@@ -61,6 +64,46 @@ class TaskTestCase(unittest.TestCase):
         rally("task start --task %s" % config.filename)
         self.assertIn("result", rally("task results"))
 
+    def test_results_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task results --uuid %s" % FAKE_TASK_UUID)
+
+    def test_abort_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task abort --uuid %s" % FAKE_TASK_UUID)
+
+    def test_delete_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task delete --uuid %s" % FAKE_TASK_UUID)
+
+    def test_detailed_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task detailed --uuid %s" % FAKE_TASK_UUID)
+
+    def test_plot2html_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task plot2html --uuid %s" % FAKE_TASK_UUID)
+
+    def test_report_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task report --uuid %s" % FAKE_TASK_UUID)
+
+    def test_sla_check_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task sla_check --uuid %s" % FAKE_TASK_UUID)
+
+    def test_status_with_wrong_task_id(self):
+        rally = utils.Rally()
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task status --uuid %s" % FAKE_TASK_UUID)
+
     def test_report(self):
         rally = utils.Rally()
         cfg = self._get_sample_task_config()
@@ -71,6 +114,8 @@ class TaskTestCase(unittest.TestCase):
             os.remove(html_file)
         rally("task report --out %s" % html_file)
         self.assertTrue(os.path.exists(html_file))
+        self.assertRaises(utils.RallyCmdError,
+                          rally, "task report --uuid %s" % FAKE_TASK_UUID)
 
     def test_delete(self):
         rally = utils.Rally()

tests/unit/cmd/test_cliutils.py

@@ -23,11 +23,14 @@ from rally.cmd.commands import show
 from rally.cmd.commands import task
 from rally.cmd.commands import use
 from rally.cmd.commands import verify
+from rally import exceptions
 from rally.openstack.common import cliutils as common_cliutils
 from tests.unit import test
 
 CONF = cfg.CONF
 
+FAKE_TASK_UUID = 'bb0f621c-29bd-495c-9d7a-d844335ed0fa'
+
 
 class CliUtilsTestCase(test.TestCase):
 
@@ -138,6 +141,14 @@ class CliUtilsTestCase(test.TestCase):
         ret = cliutils.run(["rally", "show", "keypairs"], self.categories)
         self.assertEqual(ret, 1)
 
+    @mock.patch("rally.db.task_get",
+                side_effect=exceptions.TaskNotFound(FAKE_TASK_UUID))
+    def test_run_task_not_found(self, mock_task_get):
+        ret = cliutils.run(["rally", "task", "status", "%s" % FAKE_TASK_UUID],
+                           self.categories)
+        self.assertTrue(mock_task_get.called)
+        self.assertEqual(ret, 1)
+
     @mock.patch("rally.openstack.common.cliutils.validate_args",
                 side_effect=common_cliutils.MissingArgs("missing"))
     def test_run_show_fails(self, mock_validate_args):