导语：k8s在磁盘使用率到达80%之后开始清理镜像，导致服务重启后镜像被删除。记录一下大致调整的方法

# kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 100.100.100.100
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  imagePullPolicy: IfNotPresent
  name: ubuntu
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: harbor.deepwise.com/terra-k8s
kind: ClusterConfiguration
kubernetesVersion: 1.22.15
networking:
    dnsDomain: cluster.local
    podSubnet: 10.244.0.0/16
    serviceSubnet: 100.64.0.0/16
scheduler: {}
---
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 0s
    enabled: true
  x509:
    clientCAFile: /etc/kubernetes/pki/ca.crt
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 0s
    cacheUnauthorizedTTL: 0s
cgroupDriver: systemd
clusterDNS:
- 100.64.0.10
clusterDomain: cluster.local
cpuManagerReconcilePeriod: 0s
evictionPressureTransitionPeriod: 0s
fileCheckFrequency: 0s
healthzBindAddress: 127.0.0.1
healthzPort: 10248
httpCheckFrequency: 0s
imageMinimumGCAge: 0s
kind: KubeletConfiguration
logging: {}
failSwapOn: false
featureGates: # 启用 featureGates
  NodeSwap: true # 启用 NodeSwap flag,默认为false
memorySwap:
  swapBehavior: UnlimitedSwap # swap 支持 可选:LimitedSwap(默认)/UnlimitedSwap
nodeStatusReportFrequency: 0s
nodeStatusUpdateFrequency: 0s
rotateCertificates: true
runtimeRequestTimeout: 0s
shutdownGracePeriod: 0s
shutdownGracePeriodCriticalPods: 0s
staticPodPath: /etc/kubernetes/manifests
streamingConnectionIdleTimeout: 0s
syncFrequency: 0s
volumeStatsAggPeriod: 0s
evictionHard:
  nodefs.available: "1Gi"
  imagefs.available: "1Gi"
imageGCHighThresholdPercent: 100
imageGCLowThresholdPercent: 99

# /lib/systemd/system/kubelet.service
[Unit]
Description=kubelet: The Kubernetes Node Agent
Documentation=https://kubernetes.io/docs/home/
Wants=network-online.target
After=network-online.target

[Service]
Environment="KUBELET_EXTRA_ARGS=--fail-swap-on=false --system-reserved=cpu=200m,memory=500Mi --kube-reserved=cpu=500m,memory=1Gi --eviction-hard=nodefs.available<1Gi,imagefs.available<1Gi"
ExecStart=/usr/bin/kubelet
Restart=always
StartLimitInterval=0
RestartSec=10

[Install]
WantedBy=multi-user.target

#/var/lib/kubelet/config.yaml
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 0s
    enabled: true
  x509:
    clientCAFile: /etc/kubernetes/pki/ca.crt
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 0s
    cacheUnauthorizedTTL: 0s
cgroupDriver: systemd
clusterDNS:
- 100.64.0.10
clusterDomain: cluster.local
cpuManagerReconcilePeriod: 0s
evictionPressureTransitionPeriod: 0s
failSwapOn: false
featureGates:
  NodeSwap: true
fileCheckFrequency: 0s
healthzBindAddress: 127.0.0.1
healthzPort: 10248
httpCheckFrequency: 0s
imageMinimumGCAge: 0s
kind: KubeletConfiguration
logging: {}
memorySwap:
  swapBehavior: UnlimitedSwap
nodeStatusReportFrequency: 0s
nodeStatusUpdateFrequency: 0s
rotateCertificates: true
runtimeRequestTimeout: 0s
shutdownGracePeriod: 0s
shutdownGracePeriodCriticalPods: 0s
staticPodPath: /etc/kubernetes/manifests
streamingConnectionIdleTimeout: 0s
syncFrequency: 0s
volumeStatsAggPeriod: 0s
evictionHard:
  memory.available: "500Mi"
  nodefs.available: "1Gi"
  imagefs.available: "100Gi"
imageGCHighThresholdPercent: 100
imageGCLowThresholdPercent: 99

#configmap 也需要检查
apiVersion: v1
data:
  kubelet: |
    apiVersion: kubelet.config.k8s.io/v1beta1
    authentication:
      anonymous:
        enabled: false
      webhook:
        cacheTTL: 0s
        enabled: true
      x509:
        clientCAFile: /etc/kubernetes/pki/ca.crt
    authorization:
      mode: Webhook
      webhook:
        cacheAuthorizedTTL: 0s
        cacheUnauthorizedTTL: 0s
    cgroupDriver: systemd
    clusterDNS:
    - 100.64.0.10
    clusterDomain: cluster.local
    cpuManagerReconcilePeriod: 0s
    evictionPressureTransitionPeriod: 0s
    failSwapOn: false
    featureGates:
      NodeSwap: true
    fileCheckFrequency: 0s
    healthzBindAddress: 127.0.0.1
    healthzPort: 10248
    httpCheckFrequency: 0s
    imageMinimumGCAge: 0s
    kind: KubeletConfiguration
    logging: {}
    memorySwap:
      swapBehavior: UnlimitedSwap
    nodeStatusReportFrequency: 0s
    nodeStatusUpdateFrequency: 0s
    imageGCHighThresholdPercent: 100
    imageGCLowThresholdPercent: 99
    rotateCertificates: true
    runtimeRequestTimeout: 0s
    shutdownGracePeriod: 0s
    shutdownGracePeriodCriticalPods: 0s
    staticPodPath: /etc/kubernetes/manifests
    streamingConnectionIdleTimeout: 0s
    syncFrequency: 0s
    volumeStatsAggPeriod: 0s
    evictionHard:
      nodefs.available: "1Gi"
      imagefs.available: "1Gi"
kind: ConfigMap
metadata:
  creationTimestamp: "2022-12-26T10:54:00Z"
  name: kubelet-config-1.22
  namespace: kube-system
  resourceVersion: "8154566"
  uid: 46a4fb83-9673-49a9-a075-bbbeb29e5f8d

systemctl daemon-reload
systemctl restart kubelet