Setting Up a Kubernetes (K8s) Cluster Home Lab on Ubuntu Server 24.04

Chisom Uma — Thu, 20 Feb 2025 19:28:45 +0000

Kubernetes (K8s) is an open-source container orchestration platform that allows you to manage containerized applications across a cluster of nodes efficiently. Setting up a home lab provides a practical way to learn Kubernetes and test deployments in a controlled environment.

This guide walks you through the process of setting up a Kubernetes cluster using Ubuntu Server 24.04 with two nodes: one master (kb1) and one worker (kb2).

System Requirements

Each node should have the following specifications:

CPU: 2 cores
Memory: 3GB RAM
Storage: 20GB
Node IP Addresses:
- kb1 (Master): 192.168.0.112
- kb2 (Worker): 192.168.0.113

Note: Ensure SSH connectivity between both nodes is configured properly.

Steps to Setting Up a Kubernetes (K8s) Cluster Home Lab on Ubuntu Server 24.04

Step 1: Configure Hostnames and Networking

First thing first, modify the hostname (optional) and update the host file to enable network communication.

To assign a hostname to each node, use the following command:

sudo hostnamectl set-hostname \<new-hostname\>

Example for the master node:

sudo hostnamectl set-hostname kb1

Add the IP-to-hostname mapping on each node to update network communication.

Next, modify the /etc/hosts file on each node to enable network communication:

sudo nano /etc/hosts

Then, include the mapping:

192.168.0.112  kb1192.168.0.113  kb2

Now, you should save and exit the file.

Step 2: Disable Swap and Load Kernel Modules

In this next, the first thing to do is disable the Swap and Load Kernel Modules, using the command:

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

To load the kernel modules using modpobe:

sudo modprobe overlay && sudo modprobe br\_netfilter

To make these changes persistent:

sudo modprobe overlay && sudo modprobe br\_netfilter

Next, add kernel parameters such as IP forwarding. Create a file and apply the parameters using the sysctl command:

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

Next step is to load the above kernel parameters using the command below:

sudo sysctl \--system

Step 3: Install `Containerd`

Containerd is a container runtime that manages the complete container lifecycle on a host system. It's an industry-standard core container runtime that was originally developed by Docker and later donated to the Cloud Native Computing Foundation (CNCF).

To get started with its installation, first, install the required dependencies using the commands below:

sudo apt update && sudo apt install \-y curl gnupg2 software-properties-common apt-transport-https ca-certificates

Next, add the containerd repository:

curl \-fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg \--dearmor \-o /etc/apt/trusted.gpg.d/containerd.gpgsudo add-apt-repository "deb \[arch=amd64\] https://download.docker.com/linux/ubuntu $(lsb\_release \-cs) stable"

Now, its time to install containerd:

sudo apt update && sudo apt install containerd.io \-y

Next, configure containerd to use SystemdCgroup.

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

Restart containerd to see effect:

sudo systemctl restart containerd

Verify the status:

sudo systemctl status containerd

Output:

● containerd.service - containerd container runtime
     Loaded: loaded (/usr/lib/systemd/system/containerd.service; enabled; preset: enabled)
     Active: active (running) since Mon 2025-02-17 16:20:34 UTC; 2h 17min ago
       Docs: https://containerd.io
    Process: 738 ExecStartPre=/sbin/modprobe overlay (code=exited, status=0/SUCCESS)
   Main PID: 741 (containerd)
      Tasks: 156
     Memory: 201.3M (peak: 229.5M)
        CPU: 20min 13.594s
     CGroup: /system.slice/containerd.service
             ├─  741 /usr/bin/containerd
             ├─ 1138 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 53e05d7bda37772f5869ec026de03b40d4ce532ba0303c42be5184994439b3bf -address /run/containerd/containerd.sock
             ├─ 1139 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 5398ebda2355cad57be69e19bf098e4202fe259a61270ea9cc274b81f77977ab -address /run/containerd/containerd.sock
             ├─ 1140 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id e4f1f987a5fb8db03db049b518fdfe6680b8c83617733de91620948c6bc00c95 -address /run/containerd/containerd.sock
             ├─ 1150 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 24d231aefec7bde2646ae123758907e5d464973705d8c0cd9d8db67756c19ef2 -address /run/containerd/containerd.sock
             ├─ 1547 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 4d7ddac790ef53cb30823d45ed4b675d54cf66694833158f8d15f0ba93b93e2c -address /run/containerd/containerd.sock
             ├─ 2267 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 72b50ae3cea036f3b51e18bf9b900ccd46399fed052bf51a41bcea735062f413 -address /run/containerd/containerd.sock
             ├─ 2377 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 2fcb5f2766fc1ff28a8a020c10eb1aff4b1895eb7ade8af65c72bedd0a634ead -address /run/containerd/containerd.sock
             ├─ 2434 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id d6f43f441495e4a00387114d5d7462bc54b1a592bd41bc1ee1709d16d507633b -address /run/containerd/containerd.sock
             └─27675 /usr/bin/containerd-shim-runc-v2 -namespace k8s.io -id 2b645f1523cda54eb099d35542d77347071c2cdaef648a7e5559ec01779bac29 -address /run/containerd/containerd.sock

Step 4: Add Kubernetes Package Repository

Kubernetes packages are not included in the default package repositories of Ubuntu 24.04. To install them, first, add the Kubernetes repository.

Start by downloading the public signing key for the repository using the curl command.

curl \-fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg \--dearmor \-o /etc/apt/keyrings/k8s.gpg

Next, add the repository:

echo 'deb \[signed-by=/etc/apt/keyrings/k8s.gpg\] https://pkgs.k8s.io/core:/stable:/v1.31/deb/ /' | sudo tee /etc/apt/sources.list.d/k8s.list

Step 5: Install Kubernetes Components

Install essential Kubernetes components such as kubeadm, kubelet, and kubectl to manage the Kubernetes cluster:

sudo apt updatesudo apt install kubelet kubeadm kubectl \-y

Step 6: Initialize the Kubernetes Cluster (Master Node Only)

To initialize the control plane or master node using Kubeadm, run the command:

sudo kubeadm init \--control\-plane\-endpoint=\<master-node-name\>

Example:

sudo kubeadm init \--control\-plane\-endpoint=kb1

Output:

Set up access to Kubernetes for the current user:

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

Step 7: Join Worker Nodes in the Cluster

Add worker nodes to your Kubernetes cluster using the token generated during initialization.

Example:

sudo kubeadm join 192.168.0.112:6443 \--token \<your-token\> \--discovery-token-ca\-cert-hash sha256:\<your-hash\>

Verify node status on the master node, by running the command below on your terminal:

kubectl get nodes

Output:

NAME   STATUS   ROLES           AGE   VERSION
kb1    NotReady    control-plane   10d   v1.31.5
kb2    NotReady    <none>          10d   v1.31.5

If nodes appear as NotReady, proceed to install a networking solution.

Step 8: Deploy the Calico Network Plugin

On the master node, run to install the Calico Network Plugin:

kubectl create \-f https://raw.githubusercontent.com/projectcalico/calico/v3\.28.2/manifests/calico.yaml

Confirm the node status has changed to Ready:

kubectl get nodes

Output:

NAME                                      READY   STATUS    RESTARTS      AGE
calico-kube-controllers-b8d8894fb-rz6zx   1/1     Running   3 (24h ago)   7d21h
calico-node-4klgg                         1/1     Running   0             24h
calico-node-9c9lg                         1/1     Running   0             24h
coredns-7c65d6cfc9-8f26s                  1/1     Running   3 (24h ago)   7d21h
coredns-7c65d6cfc9-sgsvc                  1/1     Running   3 (24h ago)   7d21h
etcd-kb1                                  1/1     Running   4 (24h ago)   10d
kube-apiserver-kb1                        1/1     Running   4 (24h ago)   10d
kube-controller-manager-kb1               1/1     Running   9 (24h ago)   10d
kube-proxy-h5fnm                          1/1     Running   2 (25h ago)   10d
kube-proxy-n9zts                          1/1     Running   4 (24h ago)   10d
kube-scheduler-kb1                        1/1     Running   7 (24h ago)   10d

Now, check the node status using the command:

kubectl get nodes

Output:

NAME        TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
nginx-app   NodePort   10.110.254.203   <none>        80:31809/TCP   50s

Step 9: Deploy and Test an Application

In this section, we will first deploy and expose an NGINX instance to verify the setup.

Create a Namespace:

 kubectl create ns demo-app

Check if namespace was created or not:

kubectl get namespace

Deploy NGINX replicas:

kubectl create deployment nginx\-app \--image nginx \--replicas 2 \--namespace demo\-app

Check the deployment:

kubectl get deployment \-n demo\-app

Expose the Deployment

kubectl expose deployment nginx-app \-n demo-app \--type NodePort \--port 80

Find the service port:

kubectl get svc \-n demo-app

Access the application using:

curl http://192.168.0.113:\<exposed-port\>

If successful, you should see the default NGINX welcome page.

Output:

<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

Conclusion

By following this guide, you've successfully set up a Kubernetes cluster on Ubuntu 24.04, installed essential components, and deployed a test application. This provides a solid foundation for further exploration into Kubernetes features and advanced configurations.

DEV Community: Chisom Uma

Setting Up a Kubernetes (K8s) Cluster Home Lab on Ubuntu Server 24.04

System Requirements

Steps to Setting Up a Kubernetes (K8s) Cluster Home Lab on Ubuntu Server 24.04

Step 1: Configure Hostnames and Networking

Step 2: Disable Swap and Load Kernel Modules

Step 3: Install Containerd

Step 4: Add Kubernetes Package Repository

Step 5: Install Kubernetes Components

Step 6: Initialize the Kubernetes Cluster (Master Node Only)

Step 7: Join Worker Nodes in the Cluster

Step 8: Deploy the Calico Network Plugin

Step 9: Deploy and Test an Application

Conclusion

Step 3: Install `Containerd`