Cka kubeadm init upgrade

Prep Ubuntu 24.04 & 22.04 Node

#!/bin/bash
set -eu

k8s_minor_version=1.31

prep_k8s_node(){
  sudo apt update && sudo apt upgrade -y
  sudo apt install apt-transport-https curl -y

  # https://kubernetes.io/docs/setup/production-environment/container-runtimes/
  sudo apt install containerd -y
  sudo mkdir -p /etc/containerd
  containerd config default | sudo tee /etc/containerd/config.toml > /dev/null
  #  Instruct containerd to use the Systemd cgroup hierarchy (typically cgroupv2) for managing container resources.
  sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
  sudo systemctl restart containerd
  echo "net.ipv4.ip_forward = 1" | /etc/sysctl.d/k8s.conf
  sudo sysctl --system

  # https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl
  curl -fsSL https://pkgs.k8s.io/core:/stable:/v${k8s_minor_version}/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
  echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v${k8s_minor_version}/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list
  sudo apt update
  sudo apt install -y kubelet kubeadm kubectl
  sudo apt-mark hold kubelet kubeadm kubectl

  swapon -s # returns summary text if swap is enabled
  sudo swapoff -a
  sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

  # overlay is already modprobed by containerd
  sudo modprobe br_netfilter
  echo -e "br_netfilter" | sudo tee /etc/modules-load.d/k8s.conf
  lsmod | grep overlay
  lsmod | grep br_netfilter

  echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bashrc
  sudo reboot
}

prep_k8s_node

Install kubeadm kubectl kubelet

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl

sudo apt-get update
# apt-transport-https may be a dummy package; if so, you can skip that package
sudo apt-get install -y apt-transport-https ca-certificates curl gpg

# If the directory `/etc/apt/keyrings` does not exist, it should be created before the curl command, read the note below.
# sudo mkdir -p -m 755 /etc/apt/keyrings
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.32/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

# This overwrites any existing configuration in /etc/apt/sources.list.d/kubernetes.list
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.32/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

Init Control Plane

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#initializing-your-control-plane-node

HA with LB for control see - https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/ - --control-plane-endpoint

kubeadm init --apiserver-advertise-address <local ip>

Cilium

https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy/

https://kubernetes.io/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy/
sudo tar xzvfC cilium-linux-amd64.tar.gz /usr/local/bin
rm cilium-linux-amd64.tar.gz
cilium install && cilium wait status

Join worker node

kubeadm join

Enable metrics-server api for kubectl top node

helm search hub metrics-server -o yaml
helm repo add metrics-server https://kubernetes-sigs.github.io/metrics-server/
helm install metrics-server metrics-server/metrics-server --set args[0]='--kubelet-insecure-tls'