Lab 6: Canary upgrades

Upgrading planespotter frontend app from version 1 to version 2

Let's say to test a canary, you want 80% of the traffic to go to version 1 of the frontend and 20% to version 2. We can do that by editing the virtual service and adding a destination rule like below. The new destination rule will route traffic to the planespotter-frontend, notice the host here mentioned the planespotter-frontend service.

Using Kubernetes autoscaler plus Istio a canary rollout of version 1 and 2 can be automatically managed rather than having to control the ratio of pods in version 1 and version 2 by taking advantage of virtualservices.

Route 80% of the traffic to Version 1 and 20% traffic to version 2.

Virtual service edited to add route based on weight.

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: planespotter
spec:
  hosts:
  - "*"
  gateways:
  - planespotter-gateway
  http:
  - match:
    - uri:
        exact: /index.html
    - uri:
        exact: /registry.html
    - uri:
        exact: /details.html
    - uri:
        exact: /health.html
    - uri:
        exact: /contact.html
    - uri:
        prefix: /static
    route:   
       - destination:
           host: planespotter-frontend
           subset: v2
         weight: 20
       - destination:
           host: planespotter-frontend
           subset: v1
         weight: 80

Add destination rules to route traffic from the virtual service to both versions of the app.

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: frontend-destination
spec:
  host: planespotter-frontend.planespotter.svc.cluster.local
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2

Delete the virtualservice from the previous lab:

kubectl delete virtualservice planespotter -n planespotter

Apply the new virtual service

kubectl apply -f https://raw.githubusercontent.com/Boskey/planespotter/master/kubernetes/planespotter-virtualservice-css-80-20.yaml -n planespotter

Ensure the service is created

`kubectl get virtualservices -n planespotter

Create destination rule:

kubectl apply -f https://raw.githubusercontent.com/Boskey/planespotter/master/kubernetes/frontend-destination-rule.yaml -n planespotter

Now refresh your browser a couple of times, you will notice v1 of the frontend (which is the Contacts page) visible more version 2 ( which is the feedback page)

This may take a few minutes to take effect.