K8s-pki

• https://kubernetes.io/docs/setup/best-practices/certificates/

How certificates are used by your cluster

Kubernetes requires PKI for the following operations:

• Client certificates for the kubelet to authenticate to the API server
• Server certificate for the API server endpoint
• Client certificates for administrators of the cluster to authenticate to the API server
• Client certificates for the API server to talk to the kubelets
• Client certificate for the API server to talk to etcd
• Client certificate/kubeconfig for the controller manager to talk to the API server
• Client certificate/kubeconfig for the scheduler to talk to the API server.
• Client and server certificates for the front-proxy

Note: front-proxy certificates are required only if you run kube-proxy to support an extension API server. etcd also implements mutual TLS to authenticate clients and peers.