Add invert option to rule conditions

Some conditions do not have a native counterparts, so we need a way
to invert them (aka NOT operation). This patch adds a new generic
parameter "invert", defaulting to False.

Change-Id: I50342689ba52346a5a4fbf362536b629fc688986

doc/source/usage.rst

@@ -87,6 +87,8 @@ between values from introspection data and node. Both schemes use JSON path::
 if scheme (node or data) is missing, condition compares data with
 introspection data.
 
+``invert`` boolean value, whether to invert the result of the comparison.
+
 ``multiple`` how to treat situations where the ``field`` query returns multiple
 results (e.g. the field contains a list), available options are:
 

ironic_inspector/db.py

@@ -92,6 +92,7 @@ class RuleCondition(Base):
     rule = Column(String(36), ForeignKey('rules.uuid'))
     op = Column(String(255), nullable=False)
     multiple = Column(String(255), nullable=False)
+    invert = Column(Boolean, default=False)
     # NOTE(dtantsur): while all operations now require a field, I can also
     # imagine user-defined operations that do not, thus it's nullable.
     field = Column(Text)

ironic_inspector/migrations/versions/e169a4a81d88_add_invert_field_to_rule_condition.py

@@ -0,0 +1,37 @@
+# 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.
+
+"""Add invert field to rule condition
+
+Revision ID: e169a4a81d88
+Revises: d588418040d
+Create Date: 2016-02-16 11:19:29.715615
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'e169a4a81d88'
+down_revision = 'd588418040d'
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.add_column('rule_conditions', sa.Column('invert', sa.Boolean(),
+                                               nullable=True, default=False))
+
+
+def downgrade():
+    op.drop_column('rule_conditions', 'invert')

ironic_inspector/rules.py

@@ -59,6 +59,10 @@ def conditions_schema():
                         "description": "how to treat multiple values",
                         "enum": ["all", "any", "first"]
                     },
+                    "invert": {
+                        "description": "whether to invert the result",
+                        "type": "boolean"
+                    },
                 },
                 # other properties are validated by plugins
                 "additionalProperties": True
@@ -157,6 +161,9 @@ class IntrospectionRule(object):
 
             for value in field_values:
                 result = cond_ext.check(node_info, value, cond.params)
+                if cond.invert:
+                    result = not result
+
                 if (cond.multiple == 'first'
                         or (cond.multiple == 'all' and not result)
                         or (cond.multiple == 'any' and result)):
@@ -276,6 +283,7 @@ def create(conditions_json, actions_json, uuid=None,
     act_mgr = plugins_base.rule_actions_manager()
 
     conditions = []
+    reserved_params = {'op', 'field', 'multiple', 'invert'}
     for cond_json in conditions_json:
         field = cond_json['field']
 
@@ -293,7 +301,7 @@ def create(conditions_json, actions_json, uuid=None,
 
         plugin = cond_mgr[cond_json['op']].obj
         params = {k: v for k, v in cond_json.items()
-                  if k not in ('op', 'field', 'multiple')}
+                  if k not in reserved_params}
         try:
             plugin.validate(params)
         except ValueError as exc:
@@ -301,8 +309,11 @@ def create(conditions_json, actions_json, uuid=None,
                                 '%(error)s') %
                               {'op': cond_json['op'], 'error': exc})
 
-        conditions.append((cond_json['field'], cond_json['op'],
-                           cond_json.get('multiple', 'any'), params))
+        conditions.append((cond_json['field'],
+                           cond_json['op'],
+                           cond_json.get('multiple', 'any'),
+                           cond_json.get('invert', False),
+                           params))
 
     actions = []
     for action_json in actions_json:
@@ -322,9 +333,11 @@ def create(conditions_json, actions_json, uuid=None,
             rule = db.Rule(uuid=uuid, description=description,
                            disabled=False, created_at=timeutils.utcnow())
 
-            for field, op, multiple, params in conditions:
-                rule.conditions.append(db.RuleCondition(op=op, field=field,
+            for field, op, multiple, invert, params in conditions:
+                rule.conditions.append(db.RuleCondition(op=op,
+                                                        field=field,
                                                         multiple=multiple,
+                                                        invert=invert,
                                                         params=params))
 
             for action, params in actions:

ironic_inspector/test/functional.py

@@ -309,7 +309,10 @@ class Test(Base):
                     {'field': 'local_gb', 'op': 'lt', 'value': 1000},
                     {'field': 'local_gb', 'op': 'matches', 'value': '[0-9]+'},
                     {'field': 'cpu_arch', 'op': 'contains', 'value': '[0-9]+'},
-                    {'field': 'root_disk.wwn', 'op': 'is-empty'}
+                    {'field': 'root_disk.wwn', 'op': 'is-empty'},
+                    {'field': 'inventory.interfaces[*].ipv4_address',
+                     'op': 'contains', 'value': r'127\.0\.0\.1',
+                     'invert': True, 'multiple': 'all'},
                 ],
                 'actions': [
                     {'action': 'set-attribute', 'path': '/extra/foo',

ironic_inspector/test/test_rules.py

@@ -206,6 +206,23 @@ class TestCheckConditions(BaseTest):
                          self.cond_mock.check.call_count)
         self.assertTrue(res)
 
+    def test_invert(self, mock_ext_mgr):
+        self.conditions_json = [
+            {'op': 'eq', 'field': 'memory_mb', 'value': 42,
+             'invert': True},
+        ]
+        self.rule = rules.create(conditions_json=self.conditions_json,
+                                 actions_json=self.actions_json)
+
+        mock_ext_mgr.return_value.__getitem__.return_value = self.ext_mock
+        self.cond_mock.check.return_value = False
+
+        res = self.rule.check_conditions(self.node_info, self.data)
+
+        self.cond_mock.check.assert_called_once_with(self.node_info, 1024,
+                                                     {'value': 42})
+        self.assertTrue(res)
+
     def test_no_field(self, mock_ext_mgr):
         mock_ext_mgr.return_value.__getitem__.return_value = self.ext_mock
         self.cond_mock.check.return_value = True

releasenotes/notes/rules-invert-2585173a11db3c31.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Introspection rules conditions got a new generic "invert" parameter that
+    inverts the result of the condition.