修改Docker及kubelet的Cgroup Driver

在安装kubernetes的过程中，经常会遇见如下错误

failed to create kubelet: misconfiguration: kubelet cgroup driver: "cgroupfs" is different from docker cgroup driver: "systemd"

原因是docker的Cgroup Driver和kubelet的Cgroup Driver不一致。
有两种方式解决问题，一种是修改docker,，另一种是修改kubelet；
1、修改docker的Cgroup Driver
修改/etc/docker/daemon.json文件

{
  "exec-opts": ["native.cgroupdriver=systemd"]
}

重启docker

systemctl daemon-reload
systemctl restart docker

2、修改kubelet的Cgroup Driver
修改/etc/systemd/system/kubelet.service.d/10-kubeadm.conf文件，增加--cgroup-driver=cgroupfs

Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --cgroup-driver=cgroupfs"

重启kubelet

systemctl daemon-reload
systemctl restart kubelet