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文件或者/usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf，增加--cgroup-driver=cgroupfs

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

[root@master systemd]# ls -ld /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
-rw-r--r-- 1 root root 925 Aug 13 23:29 /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
[root@master systemd]# 


[root@master systemd]# cat /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf --cgroup-driver=cgroupfs"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

重启kubelet

systemctl daemon-reload
systemctl restart kubelet