异常【kubelet cgroup driver：cgroupfs跟docker cgroup driver：systemd不一致】

  • 异常描述

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

    启动kubelet时

    #启动kubelet
service kubelet start
#查看kubelet日志
journalctl -f -u kubelet

    提示如下错误

    10月 11 20:05:18 server03 kubelet[15984]: error: failed to run Kubelet: failed to create kubelet: misconfiguration: kubelet cgroup driver: "cgroupfs" is different from docker cgroup driver: "systemd"
10月 11 20:05:18 server03 systemd[1]: kubelet.service: main process exited, code=exited, status=1/FAILURE
10月 11 20:05:18 server03 systemd[1]: Unit kubelet.service entered failed state.
10月 11 20:05:18 server03 systemd[1]: kubelet.service failed.

  • 原因分析
    kubelet文件驱动默认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。
    现在有两种方式, 一种是修改docker, 另一种是修改kubelet。
    我这里采用修改docker的方式
    ==注意==：
    网上大部分教程都是说直接修改daemon.json

    #修改daemon.json
vi /etc/docker/daemon.json
#添加如下属性
"exec-opts": [
    "native.cgroupdriver=systemd"
]

    这样会导致修改后，docker无法启动成功，提示daemon.json与/lib/systemd/system/docker.service中native.cgroupdriver=systemd重复存在。

  • 解决方案（修改docker）

    # 修改前查看docker Cgroup Driver
[root@server02 ~]# docker info
...
Server Version: 1.13.1
Storage Driver: overlay2
 Backing Filesystem: xfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: journald
Cgroup Driver: systemd
...

    # 修改docker.service
vi /lib/systemd/system/docker.service

    找到
--exec-opt native.cgroupdriver=systemd \
修改为：
--exec-opt native.cgroupdriver=cgroupfs \

    # 重启docker
systemctl daemon-reload
systemctl restart docker

    # 修改后查看docker Cgroup Driver
[root@server03 sysconfig]# docker info
...
Server Version: 1.13.1
Storage Driver: overlay2
 Backing Filesystem: xfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: journald
Cgroup Driver: cgroupfs
...

    参考链接：http://www.cnblogs.com/hongdada/p/9771857.html

异常【Failed to get system container stats for kubelet.service】

  • 异常描述

    failed to get container info for "/system.slice/kubelet.service": unknown container "/system.slice/kubelet.service"

    启动kubelet时

    service kubelet start
#查看kubelet日志
journalctl -f -u kubelet

    提示如下错误

    10月 11 19:37:46 server01 kubelet[64872]: E1011 19:37:46.150198   64872 summary.go:92] Failed to get system container stats for "/system.slice/kubelet.service": failed to get cgroup stats for "/system.slice/kubelet.service": failed to get container info for "/system.slice/kubelet.service": unknown container "/system.slice/kubelet.service"

  • 解决方案

    # 修改kubelet.service
vi /lib/systemd/system/kubelet.service

    #在ExecStart位置最后面，添加如下配置
--runtime-cgroups=/systemd/system.slice \
--kubelet-cgroups=/systemd/system.slice

    修改后的/lib/systemd/system/kubelet.service

    [Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/opt/modules/kubernetes-bins/kubelet \
  --address=192.168.1.188 \
  --hostname-override=192.168.1.188 \
  --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/imooc/pause-amd64:3.0 \
  --kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
  --network-plugin=cni \
  --cni-conf-dir=/etc/cni/net.d \
  --cni-bin-dir=/opt/modules/kubernetes-bins \
  --cluster-dns=10.68.0.2 \
  --cluster-domain=cluster.local. \
  --allow-privileged=true \
  --fail-swap-on=false \
  --logtostderr=true \
  --v=2 \
  --runtime-cgroups=/systemd/system.slice \
  --kubelet-cgroups=/systemd/system.slice
#kubelet cAdvisor 默认在所有接口监听 4194 端口的请求, 以下iptables限制内网访问
ExecStartPost=/sbin/iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 4194 -j ACCEPT
ExecStartPost=/sbin/iptables -A INPUT -s 172.16.0.0/12 -p tcp --dport 4194 -j ACCEPT
ExecStartPost=/sbin/iptables -A INPUT -s 192.168.0.0/16 -p tcp --dport 4194 -j ACCEPT
ExecStartPost=/sbin/iptables -A INPUT -p tcp --dport 4194 -j DROP
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target