1. Steps to Add a Key 1.1 Generate an SSH Key on the Client There are two key formats: Old format, the private key begins with -----BEGIN RSA PRIVATE KEY----- 1 ssh-keygen -m PEM -t rsa -b 4096 -C "mail@chenshaowen.com" New format, the private key begins with -----BEGIN OPENSSH PRIVATE KEY----- 1 ssh-keygen -t rsa -b 4096 -C "mail@chenshaowen.

The idea of the upgrade is: drain the workloads and take the traffic off, then upgrade the control plane nodes first and the worker nodes afterwards. 1. Check the cluster version 1 2 3 4 kubectl version Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.4", GitCommit:"e87da0bd6e03ec3fea7933c4b5263d151aafd07c", GitTreeState:"clean", BuildDate:"2021-02-18T16:12:00Z", GoVersion:"go1.15.8", Compiler:"gc", Platform:"linux/amd64"} Server Version: version.

1. Several Ways for a Kubernetes Pod to Reference Environment Variables 1.1 Directly Key/Value You can set the Value directly, and you can also use the current Pod’s information as the Value. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 apiVersion: v1 kind: Pod metadata: name: envar-demo labels: purpose: demonstrate-envars spec: containers: - name: envar-demo-container image: gcr.

1. Add DNS to the Host 1.1 CentOS The first method: manage DNS with /etc/resolv.conf Disable NetworkManager If you do not disable NetworkManager, the DNS records you add directly to /etc/resolv.conf are lost after you restart the NetworkManager component. 1 2 3 4 vim /etc/NetworkManager/NetworkManager.conf [main] dns=none Add dns=none to the [main] section.

1. Formatting the Disk Check the new disk 1 fdisk -l Usually, the second disk is named /dev/sdb. Partition the disk 1 fdisk /dev/sdb You will be prompted to enter parameters: command (m for help):n Partition number(1-4):1 First cylinder (1-22800,default 1):Enter command (m for help):w Format the disk as ext4 1 mkfs.