istio routing http to https upstream causes causes 302 - kubernetes-ingress

Question

My ingress gateway is at port 80 http and routing to a https destination.
With the following configuration
http://ingress-gateway.example.com/zzz
it gives 302 and the urls changes to https:
https://my-site.example.com/products
Why 302 and what am I missing?
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: my-gateway
spec:
selector:
istio: ingressgateway # use Istio default gateway implementation
servers:
- port: # Note: I am entering using this port
number: 80
name: http
protocol: HTTP
hosts:
- "*"
- port: # Note: I am NOT entering using this port
number: 443
name: https
protocol: HTTPS
hosts:
- "*"
tls:
credentialName: my-credential
---
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
name: apps-domain
spec:
hosts:
- my-site.example.com
ports:
- number: 443
name: https-my-site
protocol: HTTPS
resolution: DNS
location: MESH_EXTERNAL
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: my
spec:
hosts:
- "*"
gateways:
- my-gateway
http:
- match:
- uri:
prefix: /zzz
rewrite:
uri: /products
route:
- destination:
port:
number: 443
host: my-site.example.com
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: my-https-backend
spec:
host: my-site.example.com
trafficPolicy:
tls:
mode: SIMPLE
sni: my-site.example.com

Answer 1

You have a rewrite rule pointing to port 443
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: my
spec:
hosts:
- "*"
gateways:
- my-gateway
http:
- match:
- uri:
prefix: /zzz
rewrite:
uri: /products
route:
- destination:
port:
number: 443 # here
host: my-site.example.com