Istio version upgrade + health check
Istio will not support newer Kubernetes versions. 1.25 it is the latest one for the Istio version that we currently are recommending to install 1.15.
I would recommend to start thinking about this upgrade, normally it is better to do it sooner rather than later.
The recommended Istio version would be 1.18.x
Additionally we are still using some default pod to measure api gateway health check, MSFT team suggested to get rid of that as it is single point of failure for appgw, all services will be unavailable if default pod it is unavailable.
Recommended approach would be to redirect to the Istio gateway health-check, Istio gateway it is configured to scale automatically, meaning that if this health check fails, most likely Istio failed and this is an accurate health check.
cc. @lucynliu @nursheikh
Let me know if we can start working on this and donate this to community.