Added heat.resource_type custom constraint

This constraint will validate that a parameter value is a valid resource
type within the context of the template (that is, taking into account
the environment file(s) passed in as well).

Change-Id: I82b18d52982c2731370df9ea4ea0e398bf7702f2
Closes-Bug: #1545857

heat/engine/constraint/heat_constraints.py

@@ -0,0 +1,45 @@
+#
+#    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.
+
+import collections
+
+import six
+
+from heat.common.i18n import _
+from heat.engine import constraints
+
+
+class ResourceTypeConstraint(constraints.BaseCustomConstraint):
+
+    def validate(self, value, context, template):
+
+        if not isinstance(value, collections.Sequence):
+            return False
+
+        if isinstance(value, six.string_types):
+            value = [value]
+
+        invalid_types = []
+        for t in value:
+            try:
+                template.env.get_class(t)
+            except Exception:
+                invalid_types.append(t)
+
+        if invalid_types:
+            msg = _('The following resource types could not be found: %s')
+            types = ','.join(invalid_types)
+            self._error_message = msg % types
+            return False
+
+        return True

heat/tests/constraints/test_heat_constraints.py

@@ -0,0 +1,82 @@
+#
+#    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.
+
+import mock
+
+from heat.engine.constraint import heat_constraints as hc
+from heat.tests import common
+
+
+class ResourceTypeConstraintTest(common.HeatTestCase):
+
+    def setUp(self):
+        super(ResourceTypeConstraintTest, self).setUp()
+        self.constraint = hc.ResourceTypeConstraint()
+
+        self.mock_template = mock.MagicMock()
+        self.mock_env = mock.MagicMock()
+        self.mock_template.env = self.mock_env
+
+    def test_validate(self):
+        # Setup
+        value = ['OS::Heat::None']
+
+        # Test
+        result = self.constraint.validate(value, None, self.mock_template)
+
+        # Verify
+        self.assertTrue(result)
+        self.mock_env.get_class.assert_called_once_with(value[0])
+
+    def test_validate_failure(self):
+        # Setup
+        value = ['OS::Heat::None']
+        self.mock_env.get_class.side_effect = Exception()
+
+        # Test
+        result = self.constraint.validate(value, None, self.mock_template)
+
+        # Verify
+        self.assertFalse(result)
+        self.assertTrue('OS::Heat::None' in self.constraint._error_message)
+        self.mock_env.get_class.assert_called_once_with(value[0])
+
+    def test_validate_multiple_failures(self):
+        # Setup
+        value = ['OS::Heat::None', 'OS::Heat::RandomString']
+        self.mock_env.get_class.side_effect = [Exception(), Exception()]
+
+        # Test
+        result = self.constraint.validate(value, None, self.mock_template)
+
+        # Verify
+        self.assertFalse(result)
+        self.assertTrue('OS::Heat::None,OS::Heat::RandomString'
+                        in self.constraint._error_message)
+        self.mock_env.get_class.assert_has_calls([mock.call(value[0]),
+                                                  mock.call(value[1])])
+
+    def test_validate_single_item(self):
+        # Setup
+        value = 'OS::Heat::None'
+
+        # Test
+        result = self.constraint.validate(value, None, self.mock_template)
+
+        # Verify
+        self.assertTrue(result)
+        self.mock_env.get_class.assert_called_once_with(value)
+
+    def test_validate_non_string(self):
+        result = self.constraint.validate(dict(), None, self.mock_template)
+        self.assertFalse(result)

setup.cfg

@@ -94,6 +94,7 @@ heat.constraints =
     cinder.vtype = heat.engine.clients.os.cinder:VolumeTypeConstraint
     designate.domain = heat.engine.clients.os.designate:DesignateDomainConstraint
     glance.image = heat.engine.clients.os.glance:ImageConstraint
+    heat.resource_type = heat.engine.constraint.heat_constraints:ResourceTypeConstraint
     keystone.domain = heat.engine.clients.os.keystone.keystone_constraints:KeystoneDomainConstraint
     keystone.group = heat.engine.clients.os.keystone.keystone_constraints:KeystoneGroupConstraint
     keystone.project = heat.engine.clients.os.keystone.keystone_constraints:KeystoneProjectConstraint