Feb 12, 2026

Kubernetes Cluster Installation and Configuration

Cluster Installation and Configuration

This guide uses kubeadm to deploy a two-node cluster, with one node as the control-plane and the other as a worker-node, on virtual machines running a Debian/Ubuntu-based operating system.

Step 1: Virtual Machine Preparation (In Proxmox)

Create two VMs: One control-plane (minimum 2 vCPUs, 2 GB RAM, 20 GB disk) and one worker-node (minimum 1 vCPU, 1 GB RAM, 10 GB disk).
Assign static IPs to both nodes to prevent communication issues.

Step 2: Operating System Preparation (On Both Nodes)

Connect to each virtual machine separately and run the following commands.

Disable Swap:
- Temporarily disable swap:
```
sudo swapoff -a
```
- Comment out the swap line in /etc/fstab to make the change permanent:
```
sudo sed -i '/ swap / s/^$.*$$/#\1/g' /etc/fstab
```
Configure Kernel for Networking:
- Immediately load the necessary kernel modules:
```
sudo modprobe overlay
sudo modprobe br_netfilter
```
- Add the modules so they load automatically on reboot:
```
sudo tee /etc/modules-load.d/containerd.conf <<EOF
overlay
br_netfilter
EOF
```
- Enable packet forwarding in the kernel. Open the /etc/sysctl.conf file and ensure the following line exists and is uncommented (#):
```
net.ipv4.ip_forward = 1
```
- Apply all sysctl changes immediately:
```
sudo sysctl --system
```

Install a Container Runtime (containerd):

Install the containerd package:

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

Generate and configure the default configuration file to use the systemd cgroup driver:

sudo containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/g' /etc/containerd/config.toml

Restart the containerd service for the changes to take effect:
```
sudo systemctl restart containerd
```

Install Kubernetes Components (kubeadm, kubelet, kubectl):

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gpg
curl -fsSL [https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key](https://pkgs.k8s.io/core:/stable:/v1.28/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:/v1.28/deb/](https://pkgs.k8s.io/core:/stable:/v1.28/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

Step 3: Initialize the Control-Plane (On the control-plane node only)

Initialize the cluster:
```
sudo kubeadm init --pod-network-cidr=10.244.0.0/16
```
- Important! Save the complete kubeadm join command that the terminal will show you when it finishes. You will need it for the worker-node.

Configure kubectl for your user:

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

Install a Container Network Interface (CNI) plugin, for example Flannel:

kubectl apply -f [https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml](https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml)

Step 4: Join the Worker-Node to the Cluster (On the worker-node only)

Connect to the worker-node and run the kubeadm join command you saved in the previous step. It will look similar to this (but with your own details):

sudo kubeadm join 192.168.1.200:6443 --token yma8cv.7pr4rvudkdzxdpgt \
--discovery-token-ca-cert-hash sha256:f2a0fe0f3775812f61ae380b2a20ec9fe745d9ac8f7fa80f71c037e54d6294e6

Step 5: Final Verification (On the control-plane node)

Verify that both nodes are in the Ready state:
```
kubectl get nodes
```
The output should show both nodes in the Ready state.

You have now successfully deployed your basic Kubernetes cluster!