Add properties for id attributes

The user, tenant and similar values are ambiguous. Most contexts that
subclass oslo.context already provide some version of this and use the
_id attributes anyway.

Ideally we would deprecate these values in future but for now just
provide the alias.

Change-Id: Ia59bf69eaa83be1904abe835bfee68b785c92c54

oslo_context/context.py

@@ -32,6 +32,23 @@ def generate_request_id():
     return b'req-' + str(uuid.uuid4()).encode('ascii')
 
 
+class _new_prop(object):
+    """Create a new property that refers to an old one.
+
+    For backwards compatibility reasons we need to maintain some attributes of
+    context that should be deprecated. Create a property with a name that
+    points to an otherwise public attribute.
+    """
+    def __init__(self, old_name):
+        self.old_name = old_name
+
+    def __get__(self, obj, objtype):
+        return getattr(obj, self.old_name)
+
+    def __set__(self, obj, val):
+        return setattr(obj, self.old_name, val)
+
+
 class RequestContext(object):
 
     """Helper class to represent useful information about a request context.
@@ -67,6 +84,16 @@ class RequestContext(object):
         if overwrite or not get_current():
             self.update_store()
 
+    # NOTE(jamielennox): for now we store under the old name and reference via
+    # the new name. This is currently easier than changing the __init__
+    # arguments. In future this should be swapped and the non-_id suffixed
+    # attributes deprecated.
+    user_id = _new_prop('user')
+    project_id = _new_prop('tenant')
+    domain_id = _new_prop('domain')
+    user_domain_id = _new_prop('user_domain')
+    project_domain_id = _new_prop('project_domain')
+
     def update_store(self):
         _request_store.context = self
 

oslo_context/tests/test_context.py

@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import uuid
+
 from oslotest import base as test_base
 
 from oslo_context import context
@@ -92,3 +94,30 @@ class ContextTest(test_base.BaseTestCase):
         self.assertFalse(context.is_user_context(ctx))
         ctx = context.RequestContext(is_admin=False)
         self.assertTrue(context.is_user_context(ctx))
+
+    def test_aliased_props(self):
+        user = uuid.uuid4().hex
+        tenant = uuid.uuid4().hex
+        domain = uuid.uuid4().hex
+        user_domain = uuid.uuid4().hex
+        project_domain = uuid.uuid4().hex
+
+        ctx = context.RequestContext(user=user,
+                                     tenant=tenant,
+                                     domain=domain,
+                                     user_domain=user_domain,
+                                     project_domain=project_domain)
+
+        # original attributes
+        self.assertEqual(user, ctx.user)
+        self.assertEqual(tenant, ctx.tenant)
+        self.assertEqual(domain, ctx.domain)
+        self.assertEqual(user_domain, ctx.user_domain)
+        self.assertEqual(project_domain, ctx.project_domain)
+
+        # aliased properties
+        self.assertEqual(user, ctx.user_id)
+        self.assertEqual(tenant, ctx.project_id)
+        self.assertEqual(domain, ctx.domain_id)
+        self.assertEqual(user_domain, ctx.user_domain_id)
+        self.assertEqual(project_domain, ctx.project_domain_id)