Istio + openresty is possible ? What is common(best) practice?

In our K8S we already use Openresty. The idea was to use Openresty as third party component for Istio gateway.
I found examples how to setup NGINX, and I see NGINX as part of service mesh …

Second example, as I understand it’s NGINX as part of each side car

What is common(best) practice ?

This seems more about networking. cc @Costin_Manolache1 @rshriram