canary_ingress.yaml

# the kubernetes deployment YAML for canary deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: flaskfrontend-v2
  labels:
    app: flaskfrontend
    version: v2
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: flaskfrontend
      version: v2
  template:
    metadata:
      labels:
        app: flaskfrontend
        version: v2
    spec:
      containers:
      - name: flaskfrontend
        image: "singharunk/flaskfrontend:v2"
        imagePullPolicy: "Always"
        env:
          - name: nspace
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
          - name: SERVICE_X
            value: "flaskbackend.$(nspace).svc.cluster.local"
          - name: SERVICE_X_PORT
            value: "6000"
        ports:
        - containerPort: 5000


---

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: flaskvirtualservice
spec:
  hosts:
  - "flask.example.com" # destination hosts to which traffic is being sent. The hosts field applies to both HTTP and TCP services
  gateways:
  - flask-gateway
  http:
  - match:
    - uri:
        prefix: /list
    - uri:
        prefix: /home
    route:
    - destination:
        host: flaskfrontend.default.svc.cluster.local
        subset: v1
        port:
          number: 5000
      weight: 90
    - destination:
        host: flaskfrontend.default.svc.cluster.local
        subset: v2 #  default to pods of the flaskfrontend service with label “version: v1” (i.e., subset v1)
        port:
          number: 5000
      weight: 10

---     

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: flaskdestinationrule
spec:
  host: flaskfrontend.default.svc.cluster.local
  subsets:
  - name: v1
    labels:
      version: v1 # this is latest tag in our image
  - name: v2
    labels:
      version: v2