
Automatic merge from submit-queue Centos provider: generate SSL certificates for etcd cluster. **What this PR does / why we need it**: Support secure etcd cluster for centos provider, generate SSL certificates for etcd in default. Running it w/o SSL is exposing cluster data to everyone and is not recommended. [#39462](https://github.com/kubernetes/kubernetes/pull/39462#issuecomment-271601547) /cc @jszczepkowski @zmerlynn **Release note**: ```release-note Support secure etcd cluster for centos provider. ```