⚙️ Kubeadm Installation Guide on AWS

If you want full control over your Kubernetes cluster and prefer setting it up from scratch, kubeadm is your go-to tool.

This guide walks through installing a Kubernetes cluster manually on AWS EC2 instances using kubeadm, containerd, and Calico as the CNI plugin.

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☁️ AWS Setup — Security Group Configuration

Make sure all EC2 instances (master + workers) are part of the same security group.

🔐 Step 1: Create or Update Security Group

1. Go to the EC2 Dashboard

2. In the left menu, click Security Groups → Create Security Group

3. Set:

   • Name: Kubernetes-Cluster-SG

   • Description: Allow K8s & SSH

   • VPC: Default or your custom VPC

➕ Inbound Rules

Attach this group to all instances during launch.

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🔁 Execute on Both Master & Worker Nodes

🔧 Disable Swap (required by Kubernetes)

sudo swapoff -a

📥 Load Required Kernel Modules

cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

🧱 Set System Parameters

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

sudo sysctl --system

Verify modules:

lsmod | grep br_netfilter
lsmod | grep overlay

📦 Install Container Runtime (containerd)

sudo apt-get update
sudo apt-get install -y ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
chmod a+r /etc/apt/keyrings/docker.asc

echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu $(. /etc/os-release && echo \"$VERSION_CODENAME\") stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update
sudo apt-get install -y containerd.io

⚙️ Configure containerd for Kubernetes

containerd config default | sed -e 's/SystemdCgroup = false/SystemdCgroup = true/' -e 's/sandbox_image = \"registry.k8s.io\\/pause:3.6\"/sandbox_image = \"registry.k8s.io\\/pause:3.9\"/' | sudo tee /etc/containerd/config.toml

sudo systemctl restart containerd
sudo systemctl status containerd

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🧠 Execute ONLY on the Master Node

🚀 Initialize Kubernetes Cluster

sudo kubeadm init

📁 Set Up Local kubeconfig

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

🌐 Install Calico CNI

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

🔑 Generate Join Command for Worker Nodes

kubeadm token create --print-join-command

Copy the join command output. You’ll use it on worker nodes next.

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💻 Execute on ALL Worker Nodes

♻️ Optional: Reset pre-flight configs (if re-running)

sudo kubeadm reset pre-flight checks

🔗 Join Worker Node to Cluster

Paste the command from the master and run like so:

sudo kubeadm join <control-plane-ip>:6443 --token <token> --discovery-token-ca-cert-hash sha256:<hash> --cri-socket unix:///run/containerd/containerd.sock --v=5

⚠️ Make sure you add sudo and --v=5 as shown above.

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✅ Verify Cluster Connection (On Master)

kubectl get nodes

If all setup is correct, you’ll see both the master and worker nodes in a Ready state.

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🎉 You’ve successfully installed a production-grade Kubernetes cluster manually using kubeadm!