Information
Enable client authentication on etcd service.
Rationale:
etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive in nature and should not be available to unauthenticated clients. You should enable the client authentication via valid certificates to secure the access to the etcd service.
Impact:
All clients attempting to access the etcd server will require a valid client certificate.
Solution
Edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and set the below parameter.
--client-cert-auth='true'
Default Value:
By default, the etcd service can be queried by unauthenticated clients.