Study Notes for Kubernetes In Action, v1

Use multipass on OSX with microk8s
As much as possible, build Go demo programs (instead of Node.js)
Update any outdated or deprecated APIs
Eventually translate to Japanese

Original source at: Kubernetes In Action, v1

Multipass installation and Ubuntu VM setup

Download Multipass installler
Install Ubuntu virtual instance via Multipass. Defaults include: --cpus 1 --disk 5G --mem 1G

multipass launch --name actionbook-vm --disk 50G

Check VM info

multipass info actionbook-vm

MicroK8s installation

Log into multipass shell

multipass shell actionbook-vm

Install MicroK8s

sudo snap install microk8s --classic --channel=1.19/stable

We want to explore etcdctl later. Even though Microk8s 1.19 now uses dqlite as the default, we can revert to etcd by disabling ha-cluster:

microk8s.disable ha-cluster
sudo snap install etcd

Add the user ubuntu to the 'microk8s' group:

sudo usermod -a -G microk8s ubuntu
sudo chown -f -R ubuntu ~/.kube

Then logout and login.

Check the status while Kubernetes starts

microk8s status --wait-ready
microk8s config > microk8s.yaml

Create alias

sudo snap alias microk8s.kubectl kubectl

Turn on the services you want

microk8s enable dns storage ingress metallb
microk8s status

Confirm running services

microk8s.inspect

Docker installation

sudo apt-get update
sudo apt install docker.io
sudo docker version
sudo docker login --username **** --password ****

If you don't want to preface the docker command with sudo, create a Unix group called docker and add users to it. When the Docker daemon starts, it creates a Unix socket accessible by members of the docker group. To create the docker group and add your user:

Create the docker group. sudo groupadd docker

Add your user to the docker group. sudo usermod -aG docker $USER

Log out and log in

docker info

Test docker run busybox echo "Hello world"

Terminal setup

Shorten bash shell:

Add to ~/.bashrc

vi ~/.bashrc PS1='\W\$ '

export PROMPT_DIRTRIM=1
PS1='\u:\W\$ '

????

Reload these scripts: source ~/.bashrc source ~/.bash_profile

Install resize

sudo apt-get update
sudo apt-get install xterm
sudo apt-get install rename

Backup script

Backup from multipass instance to host computer

Assuming you keep your work files on instance 'actionbook-vm' in the directory /home/ubuntu/src, create a tar.gz file and transfer it to a local host.

multipass exec actionbook-vm -- tar -cvzf /home/ubuntu/src.tar.gz /home/ubuntu/src && multipass transfer actionbook-vm:/home/ubuntu/src.tar.gz /Users/username/K8s-in-Action-Book/src

Restore from host to multipass instance

multipass transfer /Users/username/Desktop/K8s-in-Action-Book/src.tar.gz actionbook-vm:/home/ubuntu/src/src.tar.gz

Note that multipass transfer requires the destination to be a file.

To extract a tar.gz file, use the --extract (-x) operator and specify the archive file name after the f option: tar -xvf src.tar.gz

cd into install directory mv /home/ubuntu/install/home/ubuntu/src /home/ubuntu/src

Check Initial install:

Confirm file system layout and available disk space:

df

Filesystem     1K-blocks    Used Available Use% Mounted on
udev             5103820       0   5103820   0% /dev
tmpfs            1023320    1092   1022228   1% /run
/dev/sda1       40470732 4272660  36181688  11% /
tmpfs            5116580       0   5116580   0% /dev/shm
tmpfs               5120       0      5120   0% /run/lock
tmpfs            5116580       0   5116580   0% /sys/fs/cgroup
/dev/sda15        106858    3668    103190   4% /boot/efi
/dev/loop0         93568   93568         0 100% /snap/core/8689
/dev/loop1        196608  196608         0 100% /snap/microk8s/1293