basic command

• drain

  kubectl drain [node-name]
  

• uncordon

  kubectl uncordon [node-name]
  

• cordon

  kubectl cordon [node-name]
  

upgrade control plane

• version order
  1. kube-apiserver (x)
  2. kube-controller-manager, kube-scheduler (x-1)
  3. kubelet, kube-proxy (x-2)
  4. kubectl (x-1 ~ x+1)
• version upgrade step is 0.1

backup etcd

• backup

    spec:
      containers:
      - command:
        - etcd
        - --listen-client-urls=https://127.0.0.1:2379
        - --cert-file=/etc/kubernetes/pki/etcd/server.crt
        - --key-file=/etc/kubernetes/pki/etcd/server.key
        - --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt
  

    ETCDCTL_API=3 etcdctl --endpoints=https://127.0.0.1:2379 \
    --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key \
    snapshot save /opt/snapshot-pre-boot.db
  

• restore

  etcdutl snapshot restore /opt/snapshot-pre-boot.db --data-dir /var/lib/etcd-from-backup
  

• update info (/etc/kubernetes/manifests/etcd.yaml)

    volumes:
    - hostPath:
        path: /var/lib/etcd-from-backup # Newly restored backup directory
        type: DirectoryOrCreate
      name: etcd-data
  

• tags :
• Cka