Add default release names for template versions

Release version names are easier for template authors to remember than
seemingly arbitrary dates. It should also make it clearer to new Heat
users that heat_template_version is not like a BIND zone file version
(which would be incremented with each version of the template).

Change-Id: Iae9b6a676702b2a115b18fdfb1ab2afbe5faacde
blueprint support-alias-for-heat-template-version-names

doc/source/template_guide/hot_spec.rst

@@ -96,9 +96,10 @@ Heat template version
 ~~~~~~~~~~~~~~~~~~~~~
 
 The value of ``heat_template_version`` tells Heat not only the format of the
-template but also features that will be validated and supported.
-For example, Heat currently supports the following values for the
-``heat_template_version`` key:
+template but also features that will be validated and supported. Beginning with
+the Newton release, the version can be either the date of the Heat release or
+the code name of the Heat release. Heat currently supports the following values
+for the ``heat_template_version`` key:
 
 2013-05-23
 ----------
@@ -203,14 +204,14 @@ For example, Heat currently supports the following values for the
       str_replace
       str_split
 
-2016-10-14
-----------
-    The key with value ``2016-10-14`` indicates that the YAML document is a HOT
-    template and it may contain features added and/or removed up until the
-    Newton release.  This version adds the ``yaql`` function which
+2016-10-14 | newton
+-------------------
+    The key with value ``2016-10-14`` or ``newton`` indicates that the YAML
+    document is a HOT template and it may contain features added and/or removed
+    up until the Newton release.  This version adds the ``yaql`` function which
     can be used for evaluation of complex expressions, and also adds ``equals``
-    function which can be used to compare whether two values are equal.
-    The complete list of supported functions is::
+    function which can be used to compare whether two values are equal.  The
+    complete list of supported functions is::
 
       digest
       get_attr

heat/common/exception.py

@@ -500,3 +500,8 @@ class NoActionRequired(Exception):
 
 class InvalidServiceVersion(HeatException):
     msg_fmt = _("Invalid service %(service)s version %(version)s")
+
+
+class InvalidTemplateVersions(HeatException):
+    msg_fmt = _('A template version alias %(version)s was added for a '
+                'template class that has no official YYYY-MM-DD version.')

heat/engine/service.py

@@ -1462,15 +1462,39 @@ class EngineService(service.Service):
         return result
 
     def list_template_versions(self, cnxt):
+        def find_version_class(versions, cls):
+            for version in versions:
+                if version['class'] is cls:
+                    return version
+
         mgr = templatem._get_template_extension_manager()
         _template_classes = [(name, mgr[name].plugin)
                              for name in mgr.names()]
         versions = []
-        for t in _template_classes:
+        for t in sorted(_template_classes):  # Sort to ensure dates come first
             if issubclass(t[1], cfntemplate.CfnTemplate):
-                versions.append({'version': t[0], 'type': 'cfn'})
+                type = 'cfn'
             else:
-                versions.append({'version': t[0], 'type': 'hot'})
+                type = 'hot'
+
+            # Official versions are in '%Y-%m-%d' format. Default
+            # version aliases are the Heat release code name
+            try:
+                datetime.datetime.strptime(t[0].split('.')[-1], '%Y-%m-%d')
+                versions.append({'version': t[0], 'type': type,
+                                 'class': t[1], 'aliases': []})
+            except ValueError:
+                version = find_version_class(versions, t[1])
+                if version is not None:
+                    version['aliases'].append(t[0])
+                else:
+                    raise exception.InvalidTemplateVersions(version=t[0])
+
+        # 'class' was just used to find the version that the alias
+        # maps to. Remove it so it will not show up in the output
+        for version in versions:
+            del version['class']
+
         return versions
 
     def list_template_functions(self, cnxt, template_version):

heat/tests/test_engine_service.py

@@ -934,11 +934,12 @@ class StackServiceTest(common.HeatTestCase):
 
         class DummyMgr(object):
             def names(self):
-                return ['a.b', 'c.d']
+                return ['a.2012-12-12', 'c.newton', 'c.2016-10-14',
+                        'c.something']
 
             def __getitem__(self, item):
                 m = mock.MagicMock()
-                if item == 'a.b':
+                if item == 'a.2012-12-12':
                     m.plugin = cfntemplate.CfnTemplate
                     return m
                 else:
@@ -947,10 +948,30 @@ class StackServiceTest(common.HeatTestCase):
 
         templ_mock.return_value = DummyMgr()
         templates = self.eng.list_template_versions(self.ctx)
-        expected = [{'version': 'a.b', 'type': 'cfn'},
-                    {'version': 'c.d', 'type': 'hot'}]
+        expected = [{'version': 'a.2012-12-12', 'type': 'cfn', 'aliases': []},
+                    {'version': 'c.2016-10-14',
+                     'aliases': ['c.newton', 'c.something'], 'type': 'hot'}]
         self.assertEqual(expected, templates)
 
+    @mock.patch('heat.engine.template._get_template_extension_manager')
+    def test_list_template_versions_invalid_version(self, templ_mock):
+
+        class DummyMgr(object):
+            def names(self):
+                return ['c.something']
+
+            def __getitem__(self, item):
+                m = mock.MagicMock()
+                if item == 'c.something':
+                    m.plugin = cfntemplate.CfnTemplate
+                    return m
+
+        templ_mock.return_value = DummyMgr()
+        ret = self.assertRaises(exception.InvalidTemplateVersions,
+                                self.eng.list_template_versions, self.ctx)
+        self.assertIn('A template version alias c.something was added',
+                      six.text_type(ret))
+
     @mock.patch('heat.engine.template._get_template_extension_manager')
     def test_list_template_functions(self, templ_mock):
 

heat/tests/test_template.py

@@ -522,7 +522,7 @@ class TemplateTest(common.HeatTestCase):
                                     template.Template, invalid_hot_version_tmp)
         valid_versions = ['2013-05-23', '2014-10-16',
                           '2015-04-30', '2015-10-15', '2016-04-08',
-                          '2016-10-14']
+                          '2016-10-14', 'newton']
         ex_error_msg = ('The template version is invalid: '
                         '"heat_template_version: 2012-12-12". '
                         '"heat_template_version" should be one of: %s'

heat_integrationtests/functional/test_templates.py

@@ -54,7 +54,7 @@ class TemplateAPITest(functional_base.FunctionalTestsBase):
         supported_template_versions = ["2013-05-23", "2014-10-16",
                                        "2015-04-30", "2015-10-15",
                                        "2012-12-12", "2010-09-09",
-                                       "2016-04-08", "2016-10-14"]
+                                       "2016-04-08", "2016-10-14", "newton"]
         for template in template_versions:
             self.assertIn(template.version.split(".")[1],
                           supported_template_versions)

setup.cfg

@@ -141,15 +141,16 @@ heat.event_sinks =
     zaqar-queue = heat.engine.clients.os.zaqar:ZaqarEventSink
 
 heat.templates =
+   AWSTemplateFormatVersion.2010-09-09 = heat.engine.cfn.template:CfnTemplate
+   HeatTemplateFormatVersion.2012-12-12 = heat.engine.cfn.template:HeatTemplate
    heat_template_version.2013-05-23 = heat.engine.hot.template:HOTemplate20130523
    heat_template_version.2014-10-16 = heat.engine.hot.template:HOTemplate20141016
    heat_template_version.2015-04-30 = heat.engine.hot.template:HOTemplate20150430
    heat_template_version.2015-10-15 = heat.engine.hot.template:HOTemplate20151015
    heat_template_version.2016-04-08 = heat.engine.hot.template:HOTemplate20160408
    heat_template_version.2016-10-14 = heat.engine.hot.template:HOTemplate20161014
-   HeatTemplateFormatVersion.2012-12-12 = heat.engine.cfn.template:HeatTemplate
+   heat_template_version.newton = heat.engine.hot.template:HOTemplate20161014
    HeatTemplateFormatVersion.2016-10-14 = heat.engine.cfn.template:HeatTemplate20161014
-   AWSTemplateFormatVersion.2010-09-09 = heat.engine.cfn.template:CfnTemplate
 
 [global]
 setup-hooks =