Auth Kibana

Hello, I placed a reverse proxy in front of my kibana server. Thanks to that I can check if a user is allow or not to access to kibana.
I have an index for each country (ex:France, Spain, etc) and I would like to attribute a specific user to an index.
Is there a free way to implement this, i don't want to use Shield. Maybe modify kibana code but i don't know where to start.

Sincerely,
Chris.

Unfortunately there isn't currently a great way to do this. The best current solution that doesn't require a lot of development is probably to run multiple instances of Kibana for each separate index, and change the "kibana.index" for each instance, then ensure that users only have access to the corresponding Kibana index.