Deploy K3S on Alpine

Step 1: Install Alpine from ISO

Download the standard or virtual x86_64 ISO file.
Write the ISO to a USB flash drive (using a tool like Rufus) or mount it to a virtual machine (VMware, QEMU, or VirtualBox).
Boot your machine from the ISO (make sure Secure Boot is disabled in your BIOS if needed).
At the login prompt, log in as root with no password.

Step 2: Run the Setup Script

Type the following command to start the interactive installer:

bash
```
setup-alpine
```

Use code with caution.

Follow the prompts to configure your system:
- Keymap & Variant: Select your keyboard layout (e.g., us).
- Hostname: Enter a name for your machine (e.g., alpine-host).
- Network: Choose your network interface (e.g., eth0) and select DHCP or configure a static IP.
- Root Password: Enter and confirm a strong password for the root user.
- Timezone: Select your local timezone (e.g., Asia/Singapore or UTC).
- Proxy / NTP: Choose your HTTP proxy (usually none) and NTP client (e.g., chrony or busybox).
- APK Mirror: Type f to automatically detect and select the fastest package mirror.
- SSH Server: Choose your preferred SSH server (e.g., openssh).
- Disk Installation: Select your target storage drive (e.g., sda or vda) and choose sys for a traditional full disk installation (or data/lvm if you have specific needs).
- Confirm the prompt to erase the disk and write the system.

For cloned VM

Change hostname

$ vi /etc/hostname 
$ vi /etc/hhosts 
$ hostname -F /etc/hostname

Change ip address

$ vi /etc/network/interface  
$ /etc/init.d/networking restart

Renew ssh host keys

$ cd /etc/ssh 
$ rm ssh_host_* 
$ ssh-keygen -A

Step 3: Install Chrony

$ apk add chrony
$ vi /etc/chrony/chrony.conf 
  #pool pool.ntp.org iburst
  server 192.168.122.1 iburst
$ rc-update add chronyd default
$ rc-service chronyd start
$ rc-service chronyd status

verify

chronyc sources -v
chronyc tracking

Step 4: Install k3S

update-extlinux

$ apk add --no-cache curl
$ echo "cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate 0 0" >> /etc/fstab

$ cat > /etc/cgconfig.conf <<EOF
mount {
  cpuacct = /cgroup/cpuacct;
  memory = /cgroup/memory;
  devices = /cgroup/devices;
  freezer = /cgroup/freezer;
  net_cls = /cgroup/net_cls;
  blkio = /cgroup/blkio;
  cpuset = /cgroup/cpuset;
  cpu = /cgroup/cpu;
}
EOF

$ sed -i 's/default_kernel_opts="pax_nouderef quiet rootfstype=ext4"/default_kernel_opts="pax_nouderef quiet rootfstype=ext4 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory"/g' /etc/update-extlinux.conf

$ update-extlinux
$ reboot

cni-plugins

$ apk add --no-cache cni-plugins --repository=http://dl-cdn.alpinelinux.org/alpine/edge/community
$ export PATH=$PATH:/usr/share/cni-plugins/bin
$ echo -e '#!/bin/sh\nexport PATH=$PATH:/usr/share/cni-plugins/bin' > /etc/profile.d/cni.sh
$ apk add iptables

install k3s

$ curl -sfL https://get.k3s.io | sh -

install k3s on agent/worker node

curl -sfL https://get.k3s.io | K3S_URL=https://192.168.122.51:6443 K3S_TOKEN=K10514e27dc751663b798dd9ef0adcb26f68766bebcb2dc1b2af9a669b0595b4373::server:ea26f9838b3a4c3f1089497005ca2a2b sh -

Step 5: NFS

install nfs on ubuntu export the folder install nfs client on k3s server and agent node

apk update
apk add nfs-utils
rc-update add nfsmount
rc-service nfsmount start

install helm
ref: https://helm.sh/docs/intro/install/

helm repo add nfs-subdir-external-provisioner https://kubernetes-sigs.github.io/nfs-subdir-external-provisioner/
helm repo update 
helm install nfs-subdir-external-provisioner nfs-subdir-external-provisioner/nfs-subdir-external-provisioner \
    --create-namespace \
    --namespace nfs-provisioner \
    --set nfs.server=192.168.122.1 \
    --set nfs.path=/data/persist \
    --set storageClass.name=nfs-client \
    --set storageClass.defaultClass=true

disable local-path kubectl patch storageclass local-path -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'