Information
Do not use self-signed certificates for TLS.
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.
Solution
Edit the etcd pod specification file '/etc/kubernetes/manifests/etcd.yaml' on the master node and either remove the '--auto-tls' parameter or set it to 'false'.
--auto-tls=false
Impact:
Clients will not be able to use self-signed certificates for TLS.