k8s使用kubeadm初始化报如下错误：
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz": dial tcp 127.0.0.1:10248: connect: connection refused.
docker的cgroup驱动程序默认设置为system。默认情况下Kubernetes cgroup为systemd，我们需要更改Docker cgroup驱动，
解决办法：
kubeadm reset
vim /etc/docker/daemon.json
"registry-mirrors": ["https://82m9ar63.mirror.aliyuncs.com"],
"exec-opts": ["native.cgroupdriver=systemd"]
[root@master01 ~]# systemctl daemon-reload
systemctl restart docker
重新初始化即可成功。
