AWS NLB stickysession on EKS - amazon-web-services

Question

I`m trying to apply NLB sticky session on a EKS environment.
There are 2 worker nodes(EC2) connected to NLB target group, each node has 2 nginx pods.
I wanna connect to same pod on my local system for testing.
But it looks like connected different pod every trying using 'curl' command.
this is my test yaml file and test command.
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: udptest
labels:
app: nginx
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: container
image: nginx
ports:
- containerPort: 80
nodeSelector:
zone: a
---
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: udptest2
labels:
app: nginx
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: container
image: nginx
ports:
- containerPort: 80
nodeSelector:
zone: c
---
apiVersion: v1
kind: Service
metadata:
name: nginx-nlb
annotations:
service.beta.kubernetes.io/aws-load-balancer-type: "nlb"
spec:
selector:
app: nginx
ports:
- protocol: TCP
port: 80
targetPort: 80
type: LoadBalancer
#!/bin/bash
number=0
while :
do
if [ $number -gt 2 ]; then
break
fi
curl -L -k -s -o /dev/null -w "%{http_code}\n" <nlb dns name>
done
How can i connect to specific pod by NLB`s sticy session every attempt?

Answer 1

As much as i understand ClientIP value for sessionAffinity is not supported when the service type is LoadBalancer.
You can use the Nginx ingress controller and implement the affinity over there.
https://kubernetes.github.io/ingress-nginx/examples/affinity/cookie/
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: test-ingress
annotations:
kubernetes.io/ingress.class: "nginx"
nginx.ingress.kubernetes.io/affinity: "cookie"
nginx.ingress.kubernetes.io/session-cookie-name: "test-cookie"
nginx.ingress.kubernetes.io/session-cookie-expires: "172800"
nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"
nginx.ingress.kubernetes.io/ssl-redirect: "false"
nginx.ingress.kubernetes.io/affinity-mode: persistent
nginx.ingress.kubernetes.io/session-cookie-hash: sha1
spec:
rules:
- host: example.com
http:
paths:
- path: /
backend:
serviceName: service
servicePort: port
Good article : https://zhimin-wen.medium.com/sticky-sessions-in-kubernetes-56eb0e8f257d

Answer 2

You need to enable it:
annotations:
service.beta.kubernetes.io/aws-load-balancer-type: "nlb"
service.beta.kubernetes.io/aws-load-balancer-target-group-attributes: stickiness.enabled=true,stickiness.type=source_ip