Accept None value for set-attribute

Allows the ``set-attribute`` introspection rule action
to use ``None`` as a valid value.

Co-Authored-By: Riccardo Pittau <elfosardo@gmail.com>

Change-Id: I1aa11c8095c4557107223e352424e3b718e2ab35
Story: #2004546
Task: #28299

ironic_inspector/plugins/rules.py

@@ -115,7 +115,10 @@ class FailAction(base.RuleActionPlugin):
 
 
 class SetAttributeAction(base.RuleActionPlugin):
-    REQUIRED_PARAMS = {'path', 'value'}
+    # NOTE(iurygregory): set as optional to accept None as value, check
+    # that the key 'value' is present, otherwise will raise ValueError.
+    OPTIONAL_PARAMS = {'value'}
+    REQUIRED_PARAMS = {'path'}
     # TODO(dtantsur): proper validation of path
 
     FORMATTED_PARAMS = ['value']
@@ -124,6 +127,13 @@ class SetAttributeAction(base.RuleActionPlugin):
         node_info.patch([{'op': 'add', 'path': params['path'],
                           'value': params['value']}])
 
+    def validate(self, params, **kwargs):
+        if 'value' in params:
+            super(base.RuleActionPlugin, self).validate(params, **kwargs)
+        else:
+            msg = _('missing required parameter(s): value')
+            raise ValueError(msg)
+
 
 class SetCapabilityAction(base.RuleActionPlugin):
     REQUIRED_PARAMS = {'name'}

ironic_inspector/test/unit/test_plugins_rules.py

@@ -158,6 +158,8 @@ class TestSetAttributeAction(test_base.NodeTest):
         self.assertRaises(ValueError, self.act.validate, {'value': 42})
         self.assertRaises(ValueError, self.act.validate,
                           {'path': '/extra/value'})
+        self.params['value'] = None
+        self.act.validate(self.params)
 
     @mock.patch.object(node_cache.NodeInfo, 'patch')
     def test_apply(self, mock_patch):

ironic_inspector/test/unit/test_rules.py

@@ -59,6 +59,18 @@ class TestCreateRule(BaseTest):
                           'actions': self.actions_json},
                          rule_json)
 
+    def test_create_action_none_value(self):
+        self.actions_json = [{'action': 'set-attribute',
+                              'path': '/properties/cpus', 'value': None}]
+        rule = rules.create([], self.actions_json)
+        rule_json = rule.as_dict()
+
+        self.assertTrue(rule_json.pop('uuid'))
+        self.assertEqual({'description': None,
+                          'conditions': [],
+                          'actions': self.actions_json},
+                         rule_json)
+
     def test_duplicate_uuid(self):
         rules.create([], self.actions_json, uuid=self.uuid)
         self.assertRaisesRegex(utils.Error, 'already exists',

releasenotes/notes/unset_property_instrospectionrules-78d64b8b7643e40d.yaml

@@ -0,0 +1,4 @@
+fixes:
+  - |
+    Allows the ``set-attribute`` introspection rule action to accept ``None``
+    as value for a property.