kuberneets 1.17 设置 kube-reserved, system-reserved

主要修改 kubelet的启动命令 增加reserved相关参数

[Unit]
   Description=Kubernetes Kubelet Server
   After=docker.service
   Requires=docker.service
[Service]
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/pids/system.slice/kubelet.service
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/cpu/system.slice/kubelet.service
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/cpuacct/system.slice/kubelet.service
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/cpuset/system.slice/kubelet.service
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/memory/system.slice/kubelet.service
   ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/systemd/system.slice/kubelet.service
   WorkingDirectory=/var/lib/kubelet
   EnvironmentFile=-/etc/kubernetes/config
   EnvironmentFile=-/etc/kubernetes/kubelet
   ExecStart=/root/k8s/cmd/kubelet 
               $KUBE_LOGTOSTDERR 
               $KUBE_LOG_LEVEL 
               $KUBELET_API_SERVER 
               $KUBELET_PORT 
               $KUBELET_HOSTNAME 
               $KUBELET_POD_INFRA_CONTAINER 
               $KUBELET_ARGS 
               --network-plugin=cni 
               --feature-gates=LocalStorageCapacityIsolationFSQuotaMonitoring=true 
               --kube-reserved=cpu=6,memory=8Gi,ephemeral-storage=4Gi 
               --enforce-node-allocatable=pods,kube-reserved 
               --kube-reserved-cgroup=/system.slice/kubelet.service 
               --root-dir=/home/kubelet 
               --v=2
Restart=on-failure
[Install]
WantedBy=multi-user.target

　　

在实际使用中没有增加system-reserved参数，由于有些场景预留资源给少了会早知 device busy的错误 可以参考 https://github.com/rootsongjc/qa/issues/3

上边那些 ExecStartPre  还创建的，具体参考上边的issue

添加完成后 重启kubelet 查看资源信息

Capacity:
  cpu:                48
  ephemeral-storage:  1892365528Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             131142712Ki
  nvidia.com/gpu:     2
  pods:               110
Allocatable:
  cpu:                42
  ephemeral-storage:  1888171224Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             122242104Ki
  nvidia.com/gpu:     2
  pods:               110

　　

如果 

grep CGROUP_HUGETLB /boot/config-xxxxx

CONFIG_CGROUP_HUGETLB=y

需要在kubelet.service中加入

ExecStartPre=/usr/bin/mkdir -p /sys/fs/cgroup/hugetlb/system.slice/kubelet.service

来解决 
hugetlb.1GB.limit_in_bytes: no such file or directory