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How to enable sticky sessions for a web-application exposed via a Traefik ingress controller on Konvoy

Jena Miller
  • Updated

How-To: Enable sticky sessions for a web-application exposed via Traefik ingress controller on Konvoy

Exposing a simple application with Traefik is documented at: 
https://docs.d2iq.com/ksphere/konvoy/latest/tutorials/use-ingress-load-balancer/ To setup sticky sessions, we need to use annotations.


 

        Steps:

           Deploy a simple web-application: 
kubectl run mywebapp --image="vavy/weballheaders" --labels app=mytestapp --port 80 --replicas=2

 
Next, expose the app by setting up a NodePort service with two additional annotations:
traefik.ingress.kubernetes.io/affinity: "true"
traefik.ingress.kubernetes.io/session-cookie-name: "mysession"
as defined in the mynodeport.yaml file:


apiVersion: v1
kind: Service
metadata:
  name: mynodeport
  labels:
    app: mytestapp
  annotations:
    traefik.ingress.kubernetes.io/affinity: "true"
    traefik.ingress.kubernetes.io/session-cookie-name: "mysession"
spec:
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  selector:
    app: mytestapp
  type: NodePort
Next, Apply the configuration with the command:


kubectl create -f mynodeport.yaml
Now let's configure and create the Traefik ingress object to forward incoming traffic from clients to the applications pods by using the annotation:
kubernetes.io/ingress.class: traefik as defined in the myingressyaml file:


apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: myingress
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: "app1.vavilov.org"
    http:
      paths:
      - backend:
          serviceName: mynodeport
          servicePort: 80
Next, apply the configuration with the command:


kubectl create -f myingress.yaml
As a result, we'll see that according to the service's annotation we now have cookie-based stickiness.
The url of the specific pod is stored in the cookie "mysession" (See the following screenshot illustrating this):
You can also observe the enabled applications backend stickiness in the Traefik UI as illustrated in the following screenshot: