How to let istio resolve self defined hosts - istio

Question

Scenario:
I have 2 clusters: A and B both with istio installed. I want to expose service-1 in cluster A as service-1.suffix, and let service-2 in cluster B access service-1 by: service-1.suffix. The folloing picture illustrates my idea.
In cluster A, I define a virtualService and Gateway to route the requests to service-1.
Gateway:
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: service-1
spec:
selector:
istio: ingressgateway # use istio default ingress gateway
servers:
- port:
number: 80
name: http
protocol: HTTP
hosts:
- "service-1.suffix"
VirtualService:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: service-1
spec:
hosts:
- service-1.default.svc.cluster.local
- "service-1.suffix"
gateways:
- service-1
- mesh
http:
- route:
- destination:
host: service-1.default.svc.cluster.local
port:
number: 8080
This is working fine as I can use curl to access it successfully.
curl -I -HHost:service-1.suffix http://cluster_A_proxy:31380
The next step is creating Egress and VirtualService in Cluster B. Here are my definition files:
ServiceEntry:
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
name: service-1
spec:
hosts:
- "service-1.suffix" #the global suffix mcm.com could be defined in mcm.
#addresses:
#- xxx/32
ports:
- number: 80
name: http
protocol: HTTP
resolution: STATIC
location: MESH_EXTERNAL
endpoints:
- address: 1.1.1.1 #The cluster A proxy ip
ports:
http: 31380
VirtualService:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: service-1
spec:
hosts:
- "service-1.suffix"
http:
- route:
- destination:
host: "service-1.suffix"
port:
number: 80
In Cluster B, when I try to use curl to resolve service-1.suffix, I got a DNS error saying this cannot be resolved.
curl: (6) Could not resolve host: service-1.suffix
How can I fix this?
#The command I am using in an istio app in Cluster B:
kubectl exec -it pod_name -c container_name bash
curl -I -HHost:service-1.suffix http://service-1.suffix
Edit:
When I use another resolvable hostname like www.google.com in serviceentry I can get it through, the requests to www.google.com will be redirected to service-1 in cluster A. Just the same, if I use nip.io as my suffix, it works well. However, the made up name service-1.suffix could not be resolved.

Answer 1

Define a Kubernetes ExternalName service with a random IP:
kind: Service
apiVersion: v1
metadata:
name: service1
spec:
type: ExternalName
externalName: 1.1.1.1