Hierarchical Namespace Controller support in EKS

EKS supports many add-ons so long as they don't require modifications to core control-plane pods and etcd. Based on the requirements of HNC (https://github.com/kubernetes-sigs/hierarchical-namespaces/blob/master/docs/user-guide/faq.md), I don't see a reason it would not work. However, be cautious of the word "support", as that answer implies AWS Support will help you with it.

EKS and AWS would not limit the High Availability of HNC. I recommend using a topology constraint to set it up across multiple availability zones. Read here: https://kubernetes.io/docs/concepts/scheduling-eviction/topology-spread-constraints/

This is AWS's definitive source of multi-tenancy suggestions for EKS, as you noted: https://aws.github.io/aws-eks-best-practices/security/docs/multitenancy/. If it doesn't mention HNC, then AWS has no stance on it published.

As Kubernetes is an open-source platform there are several projects and solutions that are created by the community. EKS strives to provide the best experience for our customers running Kubernetes on AWS. Our roadmap is driven by customer input and is published in GitHub[1]. Currently, we do not have any plans to provide hierarchical namespaces (HNC) natively. However, customers may consider exploring custom solutions or third-party controllers to address their immediate needs.

[1] https://github.com/aws/containers-roadmap

Thank you !