proxy_pass to istio ingressgateway (envoy)

Hello,

I have first created a istio discussion topic but I think I could get help here too.
Ref: https://discuss.istio.io/t/nginx-proxy-pass-to-istio-ingress-gateway-404/4330


I have a nginx reverse proxy running inside the nginx:alpine container that sends some requests to a service running in a k8s cluster. The k8s cluster has istio-ingressgateway controlling the routing. The istio proxies are envoy.

When I try to curl the k8s service endpoint directly from within the nginx:alpine container I get a 200 but if I curl the nginx endpoint I get a 404 from envoy. So the request from the proxy is different than the request that I get when I curl directly. Trying to figure out why.