add helper module

this module will contain helper functions used to do common,
generic actions when using CADF.

Change-Id: I29c361d161707838b706f05143e00950a16bd275

pycadf/helper/api.py

@@ -0,0 +1,40 @@
+#
+# 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 six
+
+from pycadf import cadftaxonomy
+
+
+def convert_req_action(method, details=None):
+    """Maps standard HTTP methods to equivalent CADF action
+
+    :param method: HTTP request method
+    :param details: Extra details to append to action.
+    """
+
+    mapping = {'get': cadftaxonomy.ACTION_READ,
+               'head': cadftaxonomy.ACTION_READ,
+               'post': cadftaxonomy.ACTION_CREATE,
+               'put': cadftaxonomy.ACTION_UPDATE,
+               'delete': cadftaxonomy.ACTION_DELETE,
+               'patch': cadftaxonomy.ACTION_UPDATE,
+               'options': cadftaxonomy.ACTION_READ,
+               'trace': 'capture'}
+
+    action = None
+    if isinstance(method, six.string_types):
+        action = mapping.get(method.lower())
+        if action and isinstance(details, six.string_types):
+            action += '/%s' % details
+    return action or cadftaxonomy.UNKNOWN

pycadf/tests/helper/test_api.py

@@ -0,0 +1,44 @@
+#
+# 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 pycadf import cadftaxonomy
+from pycadf.helper import api
+from pycadf.tests import base
+
+
+class TestApiHelper(base.TestCase):
+    def test_convert_req_action(self):
+        self.assertEqual(cadftaxonomy.ACTION_READ,
+                         api.convert_req_action('get'))
+        self.assertEqual(cadftaxonomy.ACTION_CREATE,
+                         api.convert_req_action('POST'))
+        self.assertEqual(cadftaxonomy.ACTION_DELETE,
+                         api.convert_req_action('deLetE'))
+
+    def test_convert_req_action_invalid(self):
+        self.assertEqual(cadftaxonomy.UNKNOWN, api.convert_req_action(124))
+        self.assertEqual(cadftaxonomy.UNKNOWN, api.convert_req_action('blah'))
+
+    def test_convert_req_action_with_details(self):
+        detail = 'compute/instance'
+        self.assertEqual(cadftaxonomy.ACTION_READ + '/%s' % detail,
+                         api.convert_req_action('GET', detail))
+        self.assertEqual(cadftaxonomy.ACTION_DELETE + '/%s' % detail,
+                         api.convert_req_action('DELETE', detail))
+
+    def test_convert_req_action_with_details_invalid(self):
+        detail = 123
+        self.assertEqual(cadftaxonomy.ACTION_READ,
+                         api.convert_req_action('GET', detail))
+        self.assertEqual(cadftaxonomy.ACTION_DELETE,
+                         api.convert_req_action('DELETE', detail))