Always return default via template-validate "Default"

Currently we redefine the value of Default when a user value is
provided, which means the data returned doesn't match the schema
defined in the template.  Instead always return the actual default
and add a "Value" key that contains the user value, if provided.

Change-Id: If4ed0b733d4e61c84167063c36cdcb234b001136
Closes-Bug: #1497310

heat/engine/api.py

@@ -458,8 +458,11 @@ def format_validate_parameter(param):
         rpc_api.PARAM_LABEL: param.label()
     }
 
-    if param.has_value():
-        res[rpc_api.PARAM_DEFAULT] = param.value()
+    if param.has_default():
+        res[rpc_api.PARAM_DEFAULT] = param.default()
+
+    if param.user_value:
+        res[rpc_api.PARAM_VALUE] = param.user_value
 
     constraint_description = []
 

heat/rpc/api.py

@@ -180,13 +180,13 @@ VALIDATE_PARAM_KEYS = (
     PARAM_ALLOWED_VALUES, PARAM_ALLOWED_PATTERN, PARAM_MAX_LENGTH,
     PARAM_MIN_LENGTH, PARAM_MAX_VALUE, PARAM_MIN_VALUE,
     PARAM_DESCRIPTION, PARAM_CONSTRAINT_DESCRIPTION, PARAM_LABEL,
-    PARAM_CUSTOM_CONSTRAINT
+    PARAM_CUSTOM_CONSTRAINT, PARAM_VALUE
 ) = (
     'Type', 'Default', 'NoEcho',
     'AllowedValues', 'AllowedPattern', 'MaxLength',
     'MinLength', 'MaxValue', 'MinValue',
     'Description', 'ConstraintDescription', 'Label',
-    'CustomConstraint'
+    'CustomConstraint', 'Value'
 )
 
 VALIDATE_PARAM_TYPES = (

heat/tests/test_validate.py

@@ -1004,8 +1004,10 @@ class ValidateTest(common.HeatTestCase):
         env_params = {'net_name': 'betternetname'}
         engine = service.EngineService('a', 't')
         res = dict(engine.validate_template(None, t, env_params))
-        self.assertEqual('betternetname',
+        self.assertEqual('defaultnet',
                          res['Parameters']['net_name']['Default'])
+        self.assertEqual('betternetname',
+                         res['Parameters']['net_name']['Value'])
 
     def test_validate_parameters_env_provided(self):
         t = template_format.parse(test_template_no_default)
@@ -1013,7 +1015,8 @@ class ValidateTest(common.HeatTestCase):
         engine = service.EngineService('a', 't')
         res = dict(engine.validate_template(None, t, env_params))
         self.assertEqual('betternetname',
-                         res['Parameters']['net_name']['Default'])
+                         res['Parameters']['net_name']['Value'])
+        self.assertNotIn('Default', res['Parameters']['net_name'])
 
     def test_validate_hot_empty_parameters_valid(self):
         t = template_format.parse(

heat_integrationtests/functional/test_template_validate.py

@@ -74,6 +74,20 @@ resources:
                                    'Type': 'Number'}}}
         self.assertEqual(expected, ret)
 
+    def test_template_validate_override_default(self):
+        env = {'parameters': {'aparam': 5}}
+        ret = self.client.stacks.validate(template=self.random_template,
+                                          environment=env)
+        expected = {'Description': 'the stack description',
+                    'Parameters': {
+                        'aparam': {'Default': 10,
+                                   'Value': 5,
+                                   'Description': 'the param description',
+                                   'Label': 'aparam',
+                                   'NoEcho': 'false',
+                                   'Type': 'Number'}}}
+        self.assertEqual(expected, ret)
+
     def test_template_validate_basic_required_param(self):
         tmpl = self.random_template.replace('default: 10', '')
         ret = self.client.stacks.validate(template=tmpl)