10-user-virtual-service-with-dark-release.yaml

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: user-virtual-service #self explanatory
  namespace: traffic-management #self explanatory
spec:
  hosts: # a virtual service can redirect requests for multiple hosts. this is more of a filtering hosts
    - user.traffic-management.retailvoice.xyz
  gateways: # a virtual service can also received requests from multiple gateway
    - traffic-management/ingressgateway # always safe to access with namespaces
  http:
    #   it actually saying when I get any requests for user.microservice.retailvoice.xyz,
    #   just redirect it to user-service.traffic-management.svc.cluster.local on port 8000
    #   if only one port configuration present in user-service.traffic-management.svc.cluster.local then
    #   you can omit the port configuration portion
    - match:
        - headers:
            mode: # custom name of header. anything you like can be given
              exact: dev  # I am trying exact match. other options are prefix, suffix
      route:
        - destination:
            host: user-service.traffic-management.svc.cluster.local # this format is safe. But if virtual service and cluster ip service are in same namespace only service name user-service would be enough
            subset: version2
    - route:
        - destination:
            host: user-service.traffic-management.svc.cluster.local # this format is safe. But if virtual service and cluster ip service are in same namespace only service name user-service would be enough
            subset: version1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: user-destination-rule #self explanatory
  namespace: traffic-management #self explanatory
spec:
  host: user-service.traffic-management.svc.cluster.local # for which incoming service it will be triggered.
  subsets:
    - name: version1 # custom name
      labels:
        version: v1 # version label we used in our deployment
    - name: version2 # custom name
      labels:
        version: v2 # version label we used in our deployment