执行 sudo kubeadm init --config kubeadm.conf 的过程中抛出下面的错误：
Unfortunately, an error has occurred:
timed out waiting for the condition
This error is likely caused by:
- The kubelet is not running
- The kubelet is unhealthy due to a misconfiguration of the node in some way (required cgroups disabled)
If you are on a systemd-powered system, you can try to troubleshoot the error with the following commands:
- 'systemctl status kubelet'
- 'journalctl -xeu kubelet'
原因是：基础镜像pause的拉取地址需要单独设置，否则还是会从k8s.gcr.io来拉取，导致init的时候卡住，并最终失败。
解决方案有2种：
- 打一个k8s.gcr.io/pause:3.1的Tag
docker tag registry.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1
- 修改kubeadm.conf
可以通过修改kubeadm.conf中的InitConfiguration的nodeRegistration:kubeletExtraArgs:pod-infra-container-image参数来设置基础镜像，大约在14行，修改后如下：
kind: InitConfiguration
nodeRegistration:
kubeletExtraArgs:
pod-infra-container-image: registry.cn-beijing.aliyuncs.com/imcto/pause:3.1
