Try Request Routing

Preparation

1. Make default namespace managed by Kmesh

2. Deploy bookinfo as sample application and sleep as curl client

3. Install service granularity waypoint for reviews service

The above steps could refer to Install Waypoint | Kmesh

Apply version-based routing

1. Run the following command to create the route rules:

kubectl apply -f -<<EOF
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v1
      weight: 100
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  trafficPolicy:
    loadBalancer:
      simple: RANDOM
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
EOF

You have configured that all traffic sent to the reviews service to route to the v1 version.

2. Confirm that all the traffic go to reviews-v1

kubectl exec deploy/sleep -- sh -c "for i in \$(seq 1 100); do curl -s http://productpage:9080/productpage | grep reviews-v.-; done"

3. If successful, the output should look like the following:

<u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>
        ...
        <u>reviews-v1-598f9b58fc-jc25r</u>
        <u>reviews-v1-598f9b58fc-jc25r</u>

Apply user-identity-based routing

Next, you will change the route configuration so that all traffic from a specific user is routed to a specific service version. In this case, all traffic from a user named Jason will be routed to the service reviews:v2.

This example is enabled by the fact that the productpage service adds a custom end-user header to all outbound HTTP requests to the reviews service.

1. Run the following command to enable user-based routing:

kubectl apply -f -<<EOF
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: reviews
        subset: v2
  - route:
    - destination:
        host: reviews
        subset: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  trafficPolicy:
    loadBalancer:
      simple: RANDOM
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3
EOF

2. Confirm the traffic

• On the /productpage of the Bookinfo app, log in as user jason. The star ratings appear next to each review.

• Log in as another user. Refresh the browser. Now the stars are gone. This is because traffic is routed to reviews:v1 for all users except Jason.

Understanding what happened

In this task, you used Kmesh to send 100% of the traffic to the v1 version of each of reviews services. You then overwrite the rule to selectively send traffic to version v2 of the reviews service based on a custom end-user header added to the request by the productpage service.

Cleanup

1. Remove the application routing rules:

kubectl delete virtualservice reviews
kubectl delete destinationrules reviews

2. If you are not planning to explore any follow-on tasks, refer to the Install Waypoint/Cleanup instructions to remove waypoint and shutdown the application.

Demo