Add convenient method to get admin roles and permissions

admin roles and admin permissions (like 'openstack.roles.xxxx')
depends on OPENSTACK_KEYSTONE_ADMIN_ROLES.
These information is needed with openstack_auth and Horizon at least
as common information.
So, this patch provide these methods as a convenient method at
openstack_auth.

Change-Id: Idad1860684b1e772fc31f16fc8c0263e49fc3919
Closes-Bug: #1536896

openstack_auth/backend.py

@@ -294,7 +294,7 @@ class KeystoneBackend(object):
             return set()
         # TODO(gabrielhurley): Integrate policy-driven RBAC
         #                      when supported by Keystone.
-        role_perms = {"openstack.roles.%s" % role['name'].lower()
+        role_perms = {utils.get_role_permission(role['name'])
                       for role in user.roles}
 
         services = []

openstack_auth/tests/tests.py

@@ -19,6 +19,7 @@ from django.contrib import auth
 from django.core.urlresolvers import reverse
 from django import http
 from django import test
+from django.test.utils import override_settings
 from keystoneauth1 import exceptions as keystone_exceptions
 from keystoneauth1.identity import v2 as v2_auth
 from keystoneauth1.identity import v3 as v3_auth
@@ -1107,3 +1108,22 @@ class PolicyTestCaseV3Admin(PolicyTestCase):
         value = policy.check((("identity", "admin_or_cloud_admin"),),
                              request=self.request)
         self.assertTrue(value)
+
+
+class RoleTestCaseAdmin(test.TestCase):
+
+    def test_get_admin_roles_with_default_value(self):
+        admin_roles = utils.get_admin_roles()
+        self.assertSetEqual({'admin'}, admin_roles)
+
+    @override_settings(OPENSTACK_KEYSTONE_ADMIN_ROLES=['foO', 'BAR', 'admin'])
+    def test_get_admin_roles(self):
+        admin_roles = utils.get_admin_roles()
+        self.assertSetEqual({'foo', 'bar', 'admin'}, admin_roles)
+
+    @override_settings(OPENSTACK_KEYSTONE_ADMIN_ROLES=['foO', 'BAR', 'admin'])
+    def test_get_admin_permissions(self):
+        admin_permissions = utils.get_admin_permissions()
+        self.assertSetEqual({'openstack.roles.foo',
+                             'openstack.roles.bar',
+                             'openstack.roles.admin'}, admin_permissions)

openstack_auth/user.py

@@ -297,10 +297,7 @@ class User(models.AbstractBaseUser, models.AnonymousUser):
 
         Returns ``True`` or ``False``.
         """
-        admin_roles = {role.lower() for role in getattr(
-            settings,
-            'OPENSTACK_KEYSTONE_ADMIN_ROLES',
-            ['admin'])}
+        admin_roles = utils.get_admin_roles()
         user_roles = {role['name'].lower() for role in self.roles}
         return not admin_roles.isdisjoint(user_roles)
 

openstack_auth/utils.py

@@ -390,3 +390,48 @@ def get_endpoint_region(endpoint):
 def using_cookie_backed_sessions():
     engine = getattr(settings, 'SESSION_ENGINE', '')
     return "signed_cookies" in engine
+
+
+def get_admin_roles():
+    """Common function for getting the admin roles from settings
+
+       Returns:
+        Set object including all admin roles.
+        If there is no role, this will return empty.
+        {
+            "foo", "bar", "admin"
+        }
+    """
+    admin_roles = {role.lower() for role
+                   in getattr(settings, 'OPENSTACK_KEYSTONE_ADMIN_ROLES',
+                              ['admin'])}
+    return admin_roles
+
+
+def get_role_permission(role):
+    """Common function for getting the permission froms arg
+
+    This format is 'openstack.roles.xxx' and 'xxx' is a real role name.
+
+    Returns:
+        String like "openstack.roles.admin"
+        If role is None, this will return None.
+    """
+    return "openstack.roles.%s" % role.lower()
+
+
+def get_admin_permissions():
+    """Common function for getting the admin permissions from settings
+
+    This format is 'openstack.roles.xxx' and 'xxx' is a real role name.
+
+    Returns:
+        Set object including all admin permission.
+        If there is no permission, this will return empty.
+        {
+            "openstack.roles.foo",
+            "openstack.roles.bar",
+            "openstack.roles.admin"
+        }
+    """
+    return {get_role_permission(role) for role in get_admin_roles()}