Move template_format from heat to heatclient

heatclient needs to (YAML) parse the template to allow it to populate
the content for get_files function calls. For this reason, template_format
(and environment_format) have been moved to heatclient so this code can be
shared by both heat and heatclient.

Change-Id: I3cc11cd57256ad539efb4dab314ac07547e9e6a2

heatclient/common/environment_format.py

@@ -0,0 +1,51 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#
+#    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.
+
+from heatclient.common.template_format import yaml_loader
+
+import yaml
+
+
+SECTIONS = (PARAMETERS, RESOURCE_REGISTRY) = \
+           ('parameters', 'resource_registry')
+
+
+def parse(env_str):
+    '''Takes a string and returns a dict containing the parsed structure.
+
+    This includes determination of whether the string is using the
+    JSON or YAML format.
+    '''
+    try:
+        env = yaml.load(env_str, Loader=yaml_loader)
+    except yaml.YAMLError as yea:
+        raise ValueError(yea)
+    else:
+        if env is None:
+            env = {}
+
+    for param in env:
+        if param not in SECTIONS:
+            raise ValueError('environment has wrong section "%s"' % param)
+
+    return env
+
+
+def default_for_missing(env):
+    '''Checks a parsed environment for missing sections.
+    '''
+    for param in SECTIONS:
+        if param not in env:
+            env[param] = {}

heatclient/common/template_format.py

@@ -0,0 +1,80 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#
+#    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 json
+import yaml
+
+HEAT_VERSIONS = (u'2012-12-12',)
+CFN_VERSIONS = (u'2010-09-09',)
+
+if hasattr(yaml, 'CSafeLoader'):
+    yaml_loader = yaml.CSafeLoader
+else:
+    yaml_loader = yaml.SafeLoader
+
+if hasattr(yaml, 'CSafeDumper'):
+    yaml_dumper = yaml.CSafeDumper
+else:
+    yaml_dumper = yaml.SafeDumper
+
+
+def _construct_yaml_str(self, node):
+    # Override the default string handling function
+    # to always return unicode objects
+    return self.construct_scalar(node)
+yaml_loader.add_constructor(u'tag:yaml.org,2002:str', _construct_yaml_str)
+# Unquoted dates like 2013-05-23 in yaml files get loaded as objects of type
+# datetime.data which causes problems in API layer when being processed by
+# openstack.common.jsonutils. Therefore, make unicode string out of timestamps
+# until jsonutils can handle dates.
+yaml_loader.add_constructor(u'tag:yaml.org,2002:timestamp',
+                            _construct_yaml_str)
+
+
+def parse(tmpl_str):
+    '''Takes a string and returns a dict containing the parsed structure.
+
+    This includes determination of whether the string is using the
+    JSON or YAML format.
+    '''
+    if tmpl_str.startswith('{'):
+        tpl = json.loads(tmpl_str)
+    else:
+        try:
+            tpl = yaml.load(tmpl_str, Loader=yaml_loader)
+        except yaml.YAMLError as yea:
+            raise ValueError(yea)
+        else:
+            if tpl is None:
+                tpl = {}
+            if u'heat_template_version' not in tpl:
+                default_for_missing(tpl, u'HeatTemplateFormatVersion',
+                                    HEAT_VERSIONS)
+    return tpl
+
+
+def default_for_missing(tpl, version_param, versions):
+    '''Checks a parsed template for missing version and sections.
+
+    This is currently only applied to YAML templates.
+    '''
+    # if version is missing, implicitly use the lastest one
+    if version_param not in tpl:
+        tpl[version_param] = versions[-1]
+
+    # create empty placeholders for any of the main dict sections
+    for param in (u'Parameters', u'Mappings', u'Resources', u'Outputs'):
+        if param not in tpl:
+            tpl[param] = {}

heatclient/tests/test_environment_format.py

@@ -0,0 +1,69 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#    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.
+
+from heatclient.common import environment_format
+
+import mock
+import testscenarios
+import testtools
+import yaml
+
+
+load_tests = testscenarios.load_tests_apply_scenarios
+
+
+class YamlEnvironmentTest(testtools.TestCase):
+
+    def test_minimal_yaml(self):
+        yaml1 = ''
+        yaml2 = '''
+parameters: {}
+resource_registry: {}
+'''
+        tpl1 = environment_format.parse(yaml1)
+        environment_format.default_for_missing(tpl1)
+        tpl2 = environment_format.parse(yaml2)
+        self.assertEqual(tpl1, tpl2)
+
+    def test_wrong_sections(self):
+        env = '''
+parameters: {}
+resource_regis: {}
+'''
+        self.assertRaises(ValueError, environment_format.parse, env)
+
+    def test_bad_yaml(self):
+        env = '''
+parameters: }
+'''
+        self.assertRaises(ValueError, environment_format.parse, env)
+
+
+class YamlParseExceptions(testtools.TestCase):
+
+    scenarios = [
+        ('scanner', dict(raised_exception=yaml.scanner.ScannerError())),
+        ('parser', dict(raised_exception=yaml.parser.ParserError())),
+        ('reader',
+         dict(raised_exception=yaml.reader.ReaderError('', '', '', '', ''))),
+    ]
+
+    def test_parse_to_value_exception(self):
+        text = 'not important'
+
+        with mock.patch.object(yaml, 'load') as yaml_loader:
+            yaml_loader.side_effect = self.raised_exception
+
+            self.assertRaises(ValueError,
+                              environment_format.parse, text)

heatclient/tests/test_template_format.py

@@ -0,0 +1,42 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#    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
+import testscenarios
+import testtools
+import yaml
+
+from heatclient.common import template_format
+
+
+load_tests = testscenarios.load_tests_apply_scenarios
+
+
+class YamlParseExceptions(testtools.TestCase):
+
+    scenarios = [
+        ('scanner', dict(raised_exception=yaml.scanner.ScannerError())),
+        ('parser', dict(raised_exception=yaml.parser.ParserError())),
+        ('reader',
+         dict(raised_exception=yaml.reader.ReaderError('', '', '', '', ''))),
+    ]
+
+    def test_parse_to_value_exception(self):
+        text = 'not important'
+
+        with mock.patch.object(yaml, 'load') as yaml_loader:
+            yaml_loader.side_effect = self.raised_exception
+
+            self.assertRaises(ValueError,
+                              template_format.parse, text)