**Authentication'' against KUBE-API server

1. --basic-auth-file=/path/to/some.csv and use this flag for ‘‘kubeapi-server’’ configuration (not recommended)
   

2. --token-auth-file=/path/to/some.csv and use this flag for ‘‘kubeapi-server’’ configuration (not recommended)
   

3. certificate

cat  csr.yaml 
apiVersion: certificates.k8s.io/v1beta1
kind: CertificateSigningRequest
metadata:
  name: akshay
spec:
  groups:
  - system:authenticated
  request: |         LS0tLS1CRUdJTiBDRVJUSUZJQ0FURSBSRVFQYnlDNEZ4QS9zbWFQQ2crSUlOZXJYdGY2TDQ9Ci0t
         LS0tRU5EIENFUlRJRklDQVRFIFJFUVVFU1QtLS0tLQo=
  signerName: kubernetes.io/kube-apiserver-client-kubelet
  usages:
  - digital signature
  - key encipherment
  - client auth