Istio-ingressgateway customization during installation - istio

Question

I need to change the 'hosts' of the Istio ingressgateway (Gateway object) from default value '*' to 'whatever' during Istio installation. We are using the IstioOperator to make customizations for our installation.
I think it should be done with k8s overlays
...
k8s:
overlays:
- kind: Gateway
name: istio-ingressgateway
patches:
- path: spec.servers.??????
value: whatever
...
What should be the expression for the path attribute ?
I found some info on https://github.com/istio/istio/blob/master/operator/pkg/patch/patch.go, but the case is not exactly the same.
So, the istio-gateway Gateway object in namespace istio-system should change from
spec:
servers:
- hosts:
- '*'
port:
name: http
number: 80
protocol: HTTP
to
spec:
servers:
- hosts:
- whatever
port:
name: http
number: 80
protocol: HTTP
We are using Istio 1.5.6
Thx !
UPDATE with a working example
Thx to #Jakub for pointing me to the right direction.
overlays:
- kind: Gateway
name: istio-ingressgateway
patches:
- path: spec.servers[0]
value:
hosts:
- whatever.dummy
port:
name: http
number: 80
protocol: HTTP

Answer 1

I am posting this as a community wiki answer for better visibility.
There is similiar question about that with answer and code example provided by #Jens Wurm.
This is a part of an overlay that will add another server entry with some example specs. Just tweak it to be the way you want it to be. You can also override your first server entry with a path of spec.servers[0] and then set the value to whatever you want it to be.
ingressGateways:
- enabled: true
k8s:
overlays:
- apiVersion: networking.istio.io/v1alpha3
kind: Gateway
name: ingressgateway
patches:
- path: spec.servers[1]
value:
hosts:
- '*.example.com'
port:
name: https
number: 443
protocol: HTTPS
tls:
credentialName: example-cert
mode: SIMPLE
privateKey: sds
serverCertificate: sds
And there is working example provided by #Peter Claes
overlays:
- kind: Gateway
name: istio-ingressgateway
patches:
- path: spec.servers[0]
value:
hosts:
- whatever.dummy
port:
name: http
number: 80
protocol: HTTP