Gateway middleware only update if user is changing (#307)

Author: rhysyngsun

src/apigateway/mitol/apigateway/backends.py

@@ -32,6 +32,12 @@ def authenticate(self, request, remote_user):
         user = None
         username = self.clean_username(remote_user)
 
+        # if the current user and the user from the backend match
+        # just return that user and do no further queries or configuration
+        if getattr(request.user, self.lookup_field, None) == username:
+            user = request.user
+            return user if self.user_can_authenticate(user) else None
+
         if self.create_unknown_user:
             user, created = User.objects.get_or_create(**{self.lookup_field: username})
         else:
@@ -48,6 +54,12 @@ async def aauthenticate(self, request, remote_user):
         user = None
         username = self.clean_username(remote_user)
 
+        # if the current user and the user from the backend match
+        # just return that user and do no further queries or configuration
+        if getattr(request.user, self.lookup_field, None) == username:
+            user = request.user
+            return user if self.user_can_authenticate(user) else None
+
         if self.create_unknown_user:
             user, created = await User.objects.aget_or_create(
                 **{self.lookup_field: username}