This bash script sets up a Kubernetes cluster by configuring either a master or a worker node based on user input. It updates the system, configures network settings, disables swap, and installs necessary components like Containerd and Kubernetes tools (kubelet, kubeadm, kubectl). For the master node, it initializes the cluster and deploys the C…

install-k8s-2node.sh

#!/bin/bash

# Setting IP and DNS names for each server
MASTER_IP="10.10.10.1"
WORKER_IP="10.10.10.2"
MASTER_DNS="k8s-master"
WORKER_DNS="k8s-worker"

# Checking the role of the node (master or worker)
if [ "$1" == "master" ]; then
  HOSTNAME=$MASTER_DNS
elif [ "$1" == "worker" ]; then
  HOSTNAME=$WORKER_DNS
else
  echo "Please specify 'master' or 'worker' as an argument."
  exit 1
fi

echo "Setting up the hostname as $HOSTNAME"
sudo hostnamectl set-hostname $HOSTNAME

echo "Updating /etc/hosts"
sudo tee -a /etc/hosts <<EOF
$MASTER_IP $MASTER_DNS
$WORKER_IP $WORKER_DNS
EOF

# Updating the system
echo "Updating the system"
sudo apt-get update && sudo apt-get upgrade -y

# Disabling swap
echo "Disabling swap"
sudo swapoff -a
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

# Setting up kernel parameters
echo "Setting up kernel parameters"
sudo tee /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

sudo tee /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF

sudo sysctl --system

# Installing Containerd
echo "Installing containerd"
sudo apt install -y curl gnupg2 software-properties-common apt-transport-https ca-certificates
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/docker.gpg
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt update
sudo apt install -y containerd.io

sudo containerd config default | sudo tee /etc/containerd/config.toml >/dev/null 2>&1
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/g' /etc/containerd/config.toml

sudo systemctl restart containerd
sudo systemctl enable containerd

# Installing Kubernetes components
echo "Installing Kubernetes components"
sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gpg

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.29/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:/v1.29/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

# Initializing or joining the cluster
if [ "$1" == "master" ]; then
  echo "Initializing Kubernetes master node"
  sudo kubeadm init --apiserver-advertise-address=$MASTER_IP --pod-network-cidr=192.168.0.0/16

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

  echo "Deploying Calico network"
  kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml

  echo "Master node setup complete!"
elif [ "$1" == "worker" ]; then
  echo "Joining worker node to the cluster"
  sudo kubeadm join $MASTER_IP:6443 --token <your_token> \
    --discovery-token-ca-cert-hash sha256:<your_hash>
fi