Docker中的Cgroup Driver:Cgroupfs 与 Systemd

在安装kubernetes的过程中，会出现

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

文件驱动默认由systemd改成cgroupfs, 而我们安装的docker使用的文件驱动是systemd, 造成不一致, 导致镜像无法启动

docker info查看

Cgroup Driver: systemd

现在有两种方式, 一种是修改docker, 另一种是修改kubelet,

修改docker:

修改或创建/etc/docker/daemon.json，加入下面的内容：

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

重启docker:

systemctl restart docker
systemctl status docker

修改kubelet:

vim /etc/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"
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

添加如下内容--cgroup-driver=systemd

或者：

# 配置kubelet使用国内pause镜像
# 配置kubelet的cgroups
# 获取docker的cgroups
$ DOCKER_CGROUPS=$(docker info | grep 'Cgroup' | cut -d' ' -f3)
$ echo $DOCKER_CGROUPS

$ cat >/etc/sysconfig/kubelet<<EOF
KUBELET_CGROUP_ARGS="--cgroup-driver=$DOCKER_CGROUPS"
KUBELET_EXTRA_ARGS="--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1"
EOF

# 启动
$ systemctl daemon-reload
$ systemctl enable kubelet && systemctl restart kubelet

或者：

DOCKER_CGROUPS=$(docker info | grep 'Cgroup' | cut -d' ' -f3)
echo $DOCKER_CGROUPS
cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=$DOCKER_CGROUPS --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.1"
EOF

# 启动
$ systemctl daemon-reload
$ systemctl enable kubelet && systemctl restart kubelet