Kubeadm Installation Guide

This guide outlines the steps needed to set up a Kubernetes cluster using kubeadm.

Pre-requisites:

• Ubuntu OS (Xenial or later)
• sudo privileges
• AWS Account
• Passion to Learn

Master & Worker Node:

Run the following commands on both the master and worker nodes to prepare them for kubeadm.

 curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

 curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"

 echo "$(cat kubectl.sha256)  kubectl" | sha256sum --check

 sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

 chmod +x kubectl
 mkdir -p ~/.local/bin
 mv ./kubectl ~/.local/bin/kubectl
 # and then append (or prepend) ~/.local/bin to $PATH

 kubectl version --client

# disable swap
sudo swapoff -a

# Create the .conf file to load the modules at bootup
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

# sysctl params required by setup, params persist across reboots
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF

# Apply sysctl params without reboot
sudo sysctl --system

## Install CRIO Runtime
sudo apt-get update -y
sudo apt-get install -y software-properties-common curl apt-transport-https ca-certificates gpg

sudo curl -fsSL https://pkgs.k8s.io/addons:/cri-o:/prerelease:/main/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/cri-o-apt-keyring.gpg
echo "deb [signed-by=/etc/apt/keyrings/cri-o-apt-keyring.gpg] https://pkgs.k8s.io/addons:/cri-o:/prerelease:/main/deb/ /" | sudo tee /etc/apt/sources.list.d/cri-o.list

sudo apt-get update -y
sudo apt-get install -y cri-o

sudo systemctl daemon-reload
sudo systemctl enable crio --now
sudo systemctl start crio.service

echo "CRI runtime installed successfully"

# Add Kubernetes APT repository and install required packages
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 -y
sudo apt-get install -y kubelet="1.29.0-*" kubectl="1.29.0-*" kubeadm="1.29.0-*"
sudo apt-get update -y
sudo apt-get install -y jq

sudo systemctl enable --now kubelet
sudo systemctl start kubelet

Master Node (Only):

a) Initialize the Kubernetes master node.

 sudo kubeadm config images pull

 sudo kubeadm init

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

 # Network Plugin = calico
 kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.26.0/manifests/calico.yaml

After succesfully running, your Kubernetes control plane will be initialized successfully.

b) Generate a token for worker nodes to join:

 kubeadm token create --print-join-command

c) Expose port 6443 in the Security group for the Worker to connect to Master Node

Worker Node (Only):

a) Run the following commands on the worker node.

sudo kubeadm reset pre-flight checks

b) Paste the join command you got from the master node and append --v=5 at the end. Make sure either you are working as sudo user or usesudo before the command

Verify if it is working as expected!

kubectl get nodes

Link to the video tutorial:

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