Change yaml output to use ruamel.yaml

This preserves the whitespace already in use and allows clean
machine output content.

Change-Id: Ic95aedeaaeb23a87984e095a3ec9c0729ffc7048
Signed-off-by: Graham Hayes <gr@ham.ie>

openstack_governance/projects.py

@@ -10,23 +10,17 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import yaml
-import yamlordereddictloader
+
+from openstack_governance import yamltools
 
 
 def load_project_file(filename='reference/projects.yaml'):
+    yaml = yamltools.YAML()
     with open(filename, 'r', encoding='utf-8') as f:
-        return yaml.load(
-            f.read(),
-            Loader=yamlordereddictloader.Loader,
-        )
+        return yaml.load(f)
 
 
 def write_project_file(data, filename='reference/projects.yaml'):
+    yaml = yamltools.YAML()
     with open(filename, 'w', encoding='utf-8') as f:
-        yaml.dump(
-            data,
-            f,
-            default_flow_style=False,
-            Dumper=yamlordereddictloader.Dumper,
-        )
+        yaml.dump(data, f)

openstack_governance/yamltools.py

@@ -0,0 +1,40 @@
+# Copyright (c) 2015 Hewlett-Packard Development Company, L.P.
+#
+# 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 ruamel.yaml
+
+
+def none_representer(dumper, data):
+    return dumper.represent_scalar('tag:yaml.org,2002:null', 'null')
+
+
+class YAML(object):
+    def __init__(self):
+        self.yaml = ruamel.yaml.YAML(typ='rt')
+        self.yaml.width = 256
+        self.yaml.allow_duplicate_keys = True
+        self.yaml.representer.add_representer(type(None), none_representer)
+        self.yaml.indent(mapping=2, sequence=4, offset=2)
+        self.yaml.Constructor.add_constructor(
+            '!encrypted/pkcs1-oaep',
+            ruamel.yaml.SafeConstructor.construct_yaml_seq,
+        )
+
+    def load(self, stream):
+        return self.yaml.load(stream)
+
+    def dump(self, data, *args, **kwargs):
+        self.yaml.dump(data, *args, **kwargs)

requirements.txt

@@ -6,3 +6,4 @@ PyYAML>=3.1.0
 six>=1.9.0
 yamlordereddictloader
 mwclient==0.8.1
+ruamel.yaml