Don't replace (and log) the same resource entry

Resources may be registered multiple times. This
ensures that logs are only emitted the first time
a resource is registered.

Change-Id: Iedd12d55007ee24ea6ecbe4fe7152ff65ea665b0

heat/engine/environment.py

@@ -197,6 +197,8 @@ class ResourceRegistry(object):
             return
 
         if name in registry and isinstance(registry[name], ResourceInfo):
+            if registry[name] == info:
+                return
             details = {
                 'path': descriptive_path,
                 'was': str(registry[name].value),

heat/tests/common.py

@@ -36,7 +36,7 @@ class HeatTestCase(testtools.TestCase):
         super(HeatTestCase, self).setUp()
         self.m = mox.Mox()
         self.addCleanup(self.m.UnsetStubs)
-        self.useFixture(fixtures.FakeLogger(level=logging.DEBUG))
+        self.logger = self.useFixture(fixtures.FakeLogger(level=logging.DEBUG))
         scheduler.ENABLE_SLEEP = False
         self.useFixture(fixtures.MonkeyPatch(
             'heat.common.exception._FATAL_EXCEPTION_FORMAT_ERRORS',

heat/tests/test_environment.py

@@ -15,6 +15,7 @@
 import fixtures
 import mock
 import os.path
+import testscenarios
 
 from oslo.config import cfg
 
@@ -29,6 +30,9 @@ from heat.tests import generic_resource
 from heat.tests import common
 
 
+load_tests = testscenarios.load_tests_apply_scenarios
+
+
 class EnvironmentTest(common.HeatTestCase):
     def setUp(self):
         super(EnvironmentTest, self).setUp()
@@ -107,6 +111,46 @@ class EnvironmentTest(common.HeatTestCase):
                                                'my_fip').value)
 
 
+class EnvironmentDuplicateTest(common.HeatTestCase):
+
+    scenarios = [
+        ('same', dict(resource_type='test.yaml',
+                      expected_equal=True)),
+        ('diff_temp', dict(resource_type='not.yaml',
+                           expected_equal=False)),
+        ('diff_map', dict(resource_type='OS::SomethingElse',
+                          expected_equal=False)),
+        ('diff_path', dict(resource_type='a/test.yaml',
+                           expected_equal=False)),
+    ]
+
+    def test_env_load(self):
+        env_initial = {u'resource_registry': {
+            u'OS::Test::Dummy': 'test.yaml'}}
+
+        env = environment.Environment()
+        env.load(env_initial)
+        info = env.get_resource_info('OS::Test::Dummy', 'something')
+        replace_log = 'Changing %s from %s to %s' % ('OS::Test::Dummy',
+                                                     'test.yaml',
+                                                     self.resource_type)
+        self.assertNotIn(replace_log, self.logger.output)
+        env_test = {u'resource_registry': {
+            u'OS::Test::Dummy': self.resource_type}}
+        env.load(env_test)
+
+        if self.expected_equal:
+            # should return exactly the same object.
+            self.assertIs(info, env.get_resource_info('OS::Test::Dummy',
+                                                      'my_fip'))
+            self.assertNotIn(replace_log, self.logger.output)
+        else:
+            self.assertIn(replace_log, self.logger.output)
+            self.assertNotEqual(info,
+                                env.get_resource_info('OS::Test::Dummy',
+                                                      'my_fip'))
+
+
 class GlobalEnvLoadingTest(common.HeatTestCase):
 
     def test_happy_path(self):