Identity Based Routing

In this task, you use Istio to send 100% of the traffic to reviews-v1. You then set a rule to selectively send traffic to reviews-v2 based on a custom end-user header added to the request by the productpage service. In this case, all traffic from a user named tester will be routed to the service reviews:v2, but all remaining traffic goes to reviews-v1.

reviews:v1 is the version that does not include the star ratings feature. reviews:v2 is the version that includes the star ratings feature.

Run the following command to re-configure the virtualService reviews you created in the previous task with the following one to enable user-based routing:

kubectl apply -n test -f - <<EOF
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts: 
  - reviews
  
  # When this field is omitted, the default gateway (mesh) will be used, which would apply the rules to all sidecars in the mesh. 
  # If a list of gateway names is provided, the rules will apply only to those gateways. 
  # To apply the rules to both gateways and sidecars, specify mesh as one of the gateway names.
  gateways:
  - bookinfo-gateway
  - mesh
  http: 
  - match: 
    - headers:
        end-user:
          exact: tester
    route:
    - destination:
        host: reviews
        subset: v2
      weight: 100
  - route:
    - destination:
        host: reviews
        subset: v1      
EOF

Now, let's open the productpage using the browser:

echo $ISTIO_IG_HOSTNAME/productpage

Output:

ac8bed13fd78247e995b42664063ce47-1403049919.us-east-1.elb.amazonaws.com/productpage

Notice here before logging, that the displayed page shows reviews-v1 and does not includes the star ratings feature.

Now, let's see what happens when logging with the tester user?

Hit the Sign In button, to log in with the tester user, with no password:

Once the tester user is in, you will notice that the displayed page include the star ratings feature and show reviews-v2 as it's expected.

And if you singed out and signed in back with any user other than tester (pick any name you wish). You will see that review stars are not there and it shows reviews-v1. This is because traffic is routed to reviews:v1 for all users except tester.

You have successfully configured Istio to route traffic based on user identity.

Try it out: Change the routing rule to direct tester user to v1, and remaining traffic to goes to v2.