Add immutable property attribute

Currently resources support only in-place update or (default)
UpdateReplace. In order to support AWS "Updates are not supported"
feature, this new property attribute is added, with default value False.
It is going to be used for denying an UpdateReplace
behavior of the resource (similar to update_allowed currently).

Change-Id: Ie94241630d9595b58ff6b84bcb94459b0785fc03
Implements: blueprint implement-aws-updates-not-supported

heat/engine/properties.py

@@ -24,10 +24,12 @@ SCHEMA_KEYS = (
     REQUIRED, IMPLEMENTED, DEFAULT, TYPE, SCHEMA,
     ALLOWED_PATTERN, MIN_VALUE, MAX_VALUE, ALLOWED_VALUES,
     MIN_LENGTH, MAX_LENGTH, DESCRIPTION, UPDATE_ALLOWED,
+    IMMUTABLE,
 ) = (
     'Required', 'Implemented', 'Default', 'Type', 'Schema',
     'AllowedPattern', 'MinValue', 'MaxValue', 'AllowedValues',
     'MinLength', 'MaxLength', 'Description', 'UpdateAllowed',
+    'Immutable',
 )
 
 
@@ -42,10 +44,10 @@ class Schema(constr.Schema):
 
     KEYS = (
         TYPE, DESCRIPTION, DEFAULT, SCHEMA, REQUIRED, CONSTRAINTS,
-        UPDATE_ALLOWED
+        UPDATE_ALLOWED, IMMUTABLE,
     ) = (
         'type', 'description', 'default', 'schema', 'required', 'constraints',
-        'update_allowed'
+        'update_allowed', 'immutable',
     )
 
     def __init__(self, data_type, description=None,
@@ -53,11 +55,13 @@ class Schema(constr.Schema):
                  required=False, constraints=None,
                  implemented=True,
                  update_allowed=False,
+                 immutable=False,
                  support_status=support.SupportStatus()):
         super(Schema, self).__init__(data_type, description, default,
                                      schema, required, constraints)
         self.implemented = implemented
         self.update_allowed = update_allowed
+        self.immutable = immutable
         self.support_status = support_status
         # validate structural correctness of schema itself
         self.validate()
@@ -119,7 +123,8 @@ class Schema(constr.Schema):
                    required=schema_dict.get(REQUIRED, False),
                    constraints=list(constraints()),
                    implemented=schema_dict.get(IMPLEMENTED, True),
-                   update_allowed=schema_dict.get(UPDATE_ALLOWED, False))
+                   update_allowed=schema_dict.get(UPDATE_ALLOWED, False),
+                   immutable=schema_dict.get(IMMUTABLE, False))
 
     @classmethod
     def from_parameter(cls, param):
@@ -145,11 +150,14 @@ class Schema(constr.Schema):
                    description=param.description,
                    required=param.required,
                    constraints=param.constraints,
-                   update_allowed=True)
+                   update_allowed=True,
+                   immutable=False)
 
     def __getitem__(self, key):
         if key == self.UPDATE_ALLOWED:
             return self.update_allowed
+        elif key == self.IMMUTABLE:
+            return self.immutable
         else:
             return super(Schema, self).__getitem__(key)
 
@@ -182,6 +190,9 @@ class Property(object):
     def update_allowed(self):
         return self.schema.update_allowed
 
+    def immutable(self):
+        return self.schema.immutable
+
     def has_default(self):
         return self.schema.default is not None
 
@@ -317,6 +328,16 @@ class Properties(collections.Mapping):
 
     def validate(self, with_value=True):
         for (key, prop) in self.props.items():
+            # check that update_allowed and immutable
+            # do not contradict each other
+            if prop.update_allowed() and prop.immutable():
+                msg = _("Property %(prop)s: %(ua)s and %(im)s "
+                        "cannot both be True") % {
+                            'prop': key,
+                            'ua': prop.schema.UPDATE_ALLOWED,
+                            'im': prop.schema.IMMUTABLE}
+                raise exception.InvalidSchemaError(message=msg)
+
             if with_value:
                 try:
                     self._get_property_value(key, validate=True)

heat/tests/test_engine_service.py

@@ -1975,6 +1975,7 @@ class StackServiceTest(HeatTestCase):
                     'type': 'string',
                     'required': False,
                     'update_allowed': False,
+                    'immutable': False,
                 },
             },
             'attributes': {

heat/tests/test_properties.py

@@ -31,6 +31,7 @@ class PropertySchemaTest(testtools.TestCase):
             'default': 'wibble',
             'required': True,
             'update_allowed': False,
+            'immutable': False,
             'constraints': [
                 {'length': {'min': 4, 'max': 8}},
             ]
@@ -51,13 +52,15 @@ class PropertySchemaTest(testtools.TestCase):
                     'default': 'wibble',
                     'required': True,
                     'update_allowed': False,
+                    'immutable': False,
                     'constraints': [
                         {'length': {'min': 4, 'max': 8}},
                     ]
                 }
             },
             'required': False,
-            'update_allowed': False
+            'update_allowed': False,
+            'immutable': False,
         }
         s = properties.Schema(properties.Schema.STRING, 'A string',
                               default='wibble', required=True,
@@ -76,6 +79,7 @@ class PropertySchemaTest(testtools.TestCase):
                     'default': 'wibble',
                     'required': True,
                     'update_allowed': False,
+                    'immutable': False,
                     'constraints': [
                         {'length': {'min': 4, 'max': 8}},
                     ]
@@ -83,6 +87,7 @@ class PropertySchemaTest(testtools.TestCase):
             },
             'required': False,
             'update_allowed': False,
+            'immutable': False,
         }
         s = properties.Schema(properties.Schema.STRING, 'A string',
                               default='wibble', required=True,
@@ -106,6 +111,7 @@ class PropertySchemaTest(testtools.TestCase):
                             'default': 'wibble',
                             'required': True,
                             'update_allowed': False,
+                            'immutable': False,
                             'constraints': [
                                 {'length': {'min': 4, 'max': 8}},
                             ]
@@ -113,10 +119,12 @@ class PropertySchemaTest(testtools.TestCase):
                     },
                     'required': False,
                     'update_allowed': False,
+                    'immutable': False,
                 }
             },
             'required': False,
             'update_allowed': False,
+            'immutable': False,
         }
         s = properties.Schema(properties.Schema.STRING, 'A string',
                               default='wibble', required=True,
@@ -164,6 +172,7 @@ class PropertySchemaTest(testtools.TestCase):
         self.assertEqual('wibble', s.default)
         self.assertTrue(s.required)
         self.assertEqual(3, len(s.constraints))
+        self.assertFalse(s.immutable)
 
     def test_from_legacy_min_length(self):
         s = properties.Schema.from_legacy({
@@ -1136,6 +1145,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "The WordPress database admin account username",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 16},
                      "description": "must begin with a letter and contain "
@@ -1150,6 +1160,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "Distribution of choice",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"allowed_values": ["F18", "F17", "U10",
                                         "RHEL-6.1", "RHEL-6.2", "RHEL-6.3"]}
@@ -1160,6 +1171,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "WebServer EC2 instance type",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"allowed_values": ["t1.micro",
                                         "m1.small",
@@ -1179,6 +1191,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "Root password for MySQL",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 41},
                      "description": "must contain only alphanumeric "
@@ -1194,12 +1207,14 @@ class PropertiesTest(testtools.TestCase):
                                 "SSH access to the instances"),
                 "required": True,
                 'update_allowed': True,
+                'immutable': False,
             },
             "DBPassword": {
                 "type": "string",
                 "description": "The WordPress database admin account password",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 41},
                      "description": "must contain only alphanumeric "
@@ -1214,6 +1229,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "The WordPress database name",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 64},
                      "description": "must begin with a letter and contain "
@@ -1319,12 +1335,14 @@ class PropertiesTest(testtools.TestCase):
                                 "SSH access to the instances"),
                 "required": True,
                 'update_allowed': True,
+                'immutable': False,
             },
             "InstanceType": {
                 "type": "string",
                 "description": "WebServer EC2 instance type",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"allowed_values": ["t1.micro", "m1.small", "m1.large",
                                         "m1.xlarge", "m2.xlarge", "m2.2xlarge",
@@ -1338,6 +1356,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "Distribution of choice",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"allowed_values": ["F18", "F17", "U10",
                                         "RHEL-6.1", "RHEL-6.2", "RHEL-6.3"],
@@ -1349,6 +1368,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "The WordPress database name",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 64},
                      "description": "Length must be between 1 and 64"},
@@ -1362,6 +1382,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "The WordPress database admin account username",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 16},
                      "description": "Length must be between 1 and 16"},
@@ -1375,6 +1396,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "The WordPress database admin account password",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 41},
                      "description": "Length must be between 1 and 41"},
@@ -1388,6 +1410,7 @@ class PropertiesTest(testtools.TestCase):
                 "description": "Root password for MySQL",
                 "required": False,
                 'update_allowed': True,
+                'immutable': False,
                 "constraints": [
                     {"length": {"min": 1, "max": 41},
                      "description": "Length must be between 1 and 41"},
@@ -1671,3 +1694,11 @@ class PropertiesValidationTest(testtools.TestCase):
             properties.Properties.schema_to_parameters_and_properties(schema)
         self.assertEqual({}, parameters)
         self.assertEqual({}, props)
+
+    def test_update_allowed_and_immutable_contradict(self):
+        schema = {'foo': properties.Schema(
+            properties.Schema.STRING,
+            update_allowed=True,
+            immutable=True)}
+        props = properties.Properties(schema, {})
+        self.assertRaises(exception.InvalidSchemaError, props.validate)