Set the default value of --limit parameter

The "--limit" parameter of heavy CLI commands should not be
infinite by default. For commands like "mistral task-list" and
"execution-list" we need to set --limit parameter by default to
some reasonable value. The proposal is 100. Otherwise it's easy
to cause a huge load on a server if the result set is not limited.

A warning message is thrown whenever these commands are executed
without using "--limit" parameter.

Change-Id: If0fead181171e5b9c590f3f4c852c6ad2541ff94
Implements: blueprint mistral-cli-default-limit-parameter

mistralclient/api/v2/action_executions.py

@@ -63,12 +63,17 @@ class ActionExecutionManager(base.ResourceManager):
 
         return self._update('/action_executions/%s' % id, data)
 
-    def list(self, task_execution_id=None):
+    def list(self, task_execution_id=None, limit=None):
         url = '/action_executions'
 
+        qparams = {}
+
         if task_execution_id:
             url = '/tasks/%s/action_executions' % task_execution_id
 
+        if limit:
+            qparams['limit'] = limit
+
         return self._list(url, response_key='action_executions')
 
     def get(self, id):

mistralclient/commands/v2/action_executions.py

@@ -182,14 +182,29 @@ class List(base.MistralLister):
             nargs='?',
             help='Task execution ID.'
         )
+        parser.add_argument(
+            '--limit',
+            type=int,
+            help='Maximum number of action-executions to return in a single '
+                 'result. limit is set to %s by default. Use --limit -1 to '
+                 'fetch the full result set.' % base.DEFAULT_LIMIT,
+            nargs='?'
+        )
 
         return parser
 
     def _get_resources(self, parsed_args):
+        if parsed_args.limit is None:
+            parsed_args.limit = base.DEFAULT_LIMIT
+            LOG.info("limit is set to %s by default. Set "
+                     "the limit explicitly using \'--limit\', if required. "
+                     "Use \'--limit\' -1 to fetch the full result set.",
+                     base.DEFAULT_LIMIT)
         mistral_client = self.app.client_manager.workflow_engine
 
         return mistral_client.action_executions.list(
-            parsed_args.task_execution_id
+            parsed_args.task_execution_id,
+            limit=parsed_args.limit,
         )
 
 

mistralclient/commands/v2/base.py

@@ -21,6 +21,9 @@ from osc_lib.command import command
 import six
 
 
+DEFAULT_LIMIT = 100
+
+
 @six.add_metaclass(abc.ABCMeta)
 class MistralLister(command.Lister):
     @abc.abstractmethod

mistralclient/commands/v2/executions.py

@@ -93,7 +93,9 @@ class List(base.MistralLister):
         parser.add_argument(
             '--limit',
             type=int,
-            help='Maximum number of executions to return in a single result.',
+            help='Maximum number of executions to return in a single result. '
+                 'limit is set to %s by default. Use --limit -1 to fetch the '
+                 'full result set.' % base.DEFAULT_LIMIT,
             nargs='?'
         )
         parser.add_argument(
@@ -122,6 +124,12 @@ class List(base.MistralLister):
         return parser
 
     def _get_resources(self, parsed_args):
+        if parsed_args.limit is None:
+            parsed_args.limit = base.DEFAULT_LIMIT
+            LOG.info("limit is set to %s by default. Set "
+                     "the limit explicitly using \'--limit\', if required. "
+                     "Use \'--limit\' -1 to fetch the full result set.",
+                     base.DEFAULT_LIMIT)
         mistral_client = self.app.client_manager.workflow_engine
 
         return mistral_client.executions.list(

mistralclient/commands/v2/tasks.py

@@ -80,6 +80,14 @@ class List(base.MistralLister):
             action='append',
             help='Filters. Can be repeated.'
         )
+        parser.add_argument(
+            '--limit',
+            type=int,
+            help='Maximum number of tasks to return in a single result. '
+                 'limit is set to %s by default. Use --limit -1 to fetch the '
+                 'full result set.' % base.DEFAULT_LIMIT,
+            nargs='?'
+        )
 
         return parser
 
@@ -87,10 +95,17 @@ class List(base.MistralLister):
         return format_list
 
     def _get_resources(self, parsed_args):
+        if parsed_args.limit is None:
+            parsed_args.limit = base.DEFAULT_LIMIT
+            LOG.info("limit is set to %s by default. Set "
+                     "the limit explicitly using \'--limit\', if required. "
+                     "Use \'--limit\' -1 to fetch the full result set.",
+                     base.DEFAULT_LIMIT)
         mistral_client = self.app.client_manager.workflow_engine
 
         return mistral_client.tasks.list(
             parsed_args.workflow_execution,
+            limit=parsed_args.limit,
             **base.get_filters(parsed_args)
         )
 

mistralclient/tests/functional/cli/v2/cli_tests_v2.py

@@ -97,6 +97,16 @@ class SimpleMistralCLITests(base.MistralCLIAuth):
             ['ID', 'Name', 'Workflow name', 'State', 'Accepted']
         )
 
+    def test_action_execution_list_with_limit(self):
+        act_execs = self.parser.listing(
+            self.mistral(
+                'action-execution-list',
+                params='--limit 1'
+            )
+        )
+
+        self.assertEqual(1, len(act_execs))
+
 
 class WorkbookCLITests(base_v2.MistralClientTestBase):
     """Test suite checks commands to work with workbooks."""
@@ -853,6 +863,26 @@ class TaskCLITests(base_v2.MistralClientTestBase):
 
         self.assertEqual('goodbye', tasks[0]['Name'])
 
+    def test_task_list_with_limit(self):
+        wf_exec = self.execution_create(
+            "%s input task_name" % self.reverse_wf['Name']
+        )
+
+        exec_id = self.get_field_value(wf_exec, 'ID')
+
+        self.assertTrue(self.wait_execution_success(exec_id))
+
+        tasks = self.parser.listing(self.mistral('task-list'))
+
+        tasks = self.parser.listing(
+            self.mistral(
+                'task-list',
+                params='--limit 1'
+            )
+        )
+
+        self.assertEqual(1, len(tasks))
+
 
 class ActionCLITests(base_v2.MistralClientTestBase):
     """Test suite checks commands to work with actions."""

mistralclient/tests/unit/v2/test_cli_executions.py

@@ -229,7 +229,7 @@ class TestCLIExecutionsV2(base.BaseCommandTest):
 
         self.call(execution_cmd.List)
         self.client.executions.list.assert_called_once_with(
-            limit=None,
+            limit=100,
             marker='',
             sort_dirs='asc',
             sort_keys='created_at',

releasenotes/notes/set-default-limit-value-7e293d843d6d85ac.yaml

@@ -0,0 +1,7 @@
+---
+critical:
+  - |
+    The "--limit" parameter of heavy CLI commands like "task-list" and
+    "execution-list" and "action-execution-list" is set to "100" by
+    default to avoid the huge load on server. To fetch the full result
+    set, user may use "--limit -1".