**Optional* Edit /etc/kubernetes/controller-manager and remove --machines=127.0.0.1 from the KUBELET_ADDRESSES. Leaving this in won't hurt anything but it will cause the output to note that the 127.0.0.1 node is NotReady because we will not be configuring one in this guide.
```
KUBELET_ADDRESSES=""
KUBE_CONTROLLER_MANAGER_ARGS=""
```
* Edit /etc/etcd/etcd.conf,let the etcd to listen all the ip instead of 127.0.0.1, if not, you will get the error like "connection refused"