4-gateway.yaml

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: ingressgateway  #self explanatory
  namespace: default #self explantory
spec:
  servers: # can have multiple server configuration
    - port: # this configuration actually means that we will be allow http connection on port 80 for 3 domains which are listed under hosts
        number: 80
        name: http
        protocol: HTTP
      hosts: # 3 domains for which we will be accepting requests
        - microservice.retailvoice.xyz
        - user.microservice.retailvoice.xyz
        - product.microservice.retailvoice.xyz