KEINOS' Blog

Official blog of KEINOS but mostly for my own reference. A Japanese made in Mexico with Mexican quality. Who monkey around the jungle of codes. ;-)

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Project maintained by KEINOS Hosted on GitHub Pages — Theme by mattgraham

INDEX

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K3OS

Set password

sudo passwd rancher

SSH Access

• Path: /var/lib/rancher/k3os/config.yaml

ssh_authorized_keys:
- "ssh-rsa AAAA..."
- "github:KEINOS"

• Ref:
  • https://github.com/rancher/k3os#configuration-reference

Login via SSH with GitHub account

ssh -i ~/.ssh/id_rsa [email protected]

• ~/.ssh/id_rsa
  • The secret key of GitHub account or the one set in config.yaml.
• rancher
  • Login user
• 192.168.10.123
  • IP address of the K3OS server
• If Permission denied (publickey,keyboard-interactive). appears during login then the publickey of GitHub account is not added to the below path:
  • /var/lib/rancher/etc/config.yaml

Shutdown

# K3OS is based on Alpine linux so it does not have a shutdown command.
sudo poweroff

Basic kubectl commands

• kubectl get - リソースの一覧を表示
• kubectl describe - 単一リソースに関する詳細情報を表示
• kubectl logs - 単一Pod上の単一コンテナ内のログを表示
• kubectl exec - 単一Pod上の単一コンテナ内でコマンドを実行

View nodes

kubectl get nodes

View pod information

• To print existing Pods.

  kubectl get pods
  

• To view what containers are inside that Pod and what images are used to build those containers.

  kubectl describe pods
  

Get Pod name and Pod log

kubectl get pods -o go-template --template '\n'

$ export POD_NAME=$(kubectl get pods -o go-template --template '\n')
$ echo Name of the Pod: $POD_NAME
...
$ kubectl logs $POD_NAME
...

Get inside the Pod

kubectl exec -it $POD_NAME -- /bin/bash

Path of the key (Node Token) to share with other nodes

The token of the server node, used as the value of “K3S_TOKEN” when configuring the worker node. You need to have root privileges to read this file.

/var/lib/rancher/k3s/server/node-token

Set up worker node

• Ref:
  • https://rancher.com/docs/k3s/latest/en/quick-start/#install-script

• Install k3s with worker node configuration

    sudo su -
    curl -sfL https://get.k3s.io | K3S_URL=https://<myserver>:6443 K3S_TOKEN=<myservernodetoken> INSTALL_K3S_VERSION=v<X.Y.Z> K3S_NODE_NAME=<this_node_name> sh -
  

Install Rancher on VM

• Preparation

sudo su -
mkdir -p /etc/rancher/rke2
vi /etc/rancher/rke2/config.yaml

token: <mysecretkey>
tls-san:
  - <ip_address_of_the_server>

• Install Rancherd

curl -sfL https://get.rancher.io | sh -
rancherd --help

• Set and start service

systemctl enable rancherd-server.service
systemctl start rancherd-server.service

• Check service

```bash journalctl -eu rancherd-server -f

K3S on RaspberryPi3

Before K3S installation

• Use 64bit RaspberryPi OS Lite.
• On RaspberryPi you need to add the below to the /boot/cmdline.txt file:
  • cgroup_memory=1 cgroup_enable=memory
• Make sure the the below configuration is added to the /boot/config.txt file:
  • arm_64bit=1
  • gpu_mem=16

Japanese Manual of K3S

• https://rancher.co.jp/pdfs/K3s-eBook4Styles0507.pdf

Difference between “agent” and “worker” node

Difference between “cluster” and “server” node