suside

Kubernetes + HAProxy sticky session affinity

1. Make sure you have balance source in haproxy.
2. Backend server section in haproxy config should have all your k8s nodes.
3. sessionAffinity in k8s is irrelevant.
4. Exposed k8s service need to have nodePort set and this annotation:

kubectl annotate service myService service.beta.kubernetes.io/external-traffic=OnlyLocal

This will cause internal k8s loadbalancer on nodeⁿ to route traffic only to pod on nodeⁿ. From Haproxy point of view it will look like nodeⁿ:nodePort === pod on nodeⁿ:port thus disabling k8s LB completly.