Building a Kubernetes 1.27 Cluster with kubeadm

 

This lab will allow you to practice the process of creating a new Kubernetes cluster. You will be given a set of Linux machines and the ability to configure them into a working Kubernetes cluster. This will help you develop the skills required to build your own Kubernetes clusters in the real world.

 

INSTALL PACKAGES ON EACH OF THE NODES  

 

Create the configuration file for containerd:

cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf

overlay

br_netfilter

EOF

 

Load the modules:

sudo modprobe overlay

sudo modprobe br_netfilter

 

Set the system configurations for Kubernetes networking:

cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf

net.bridge.bridge-nf-call-iptables = 1

net.ipv4.ip_forward = 1

net.bridge.bridge-nf-call-ip6tables = 1

EOF

 

Apply the new settings:

sudo sysctl --system

 

 

 

Install containerd:

sudo apt update

sudo apt install -y docker.io

 

Create the default configuration file for containerd:

sudo mkdir -p /etc/containerd

 

Generate the default containerd configuration, and save it to the newly created default file:

sudo containerd config default | sudo tee /etc/containerd/config.toml

 

Restart containerd to ensure the new configuration file is used:

sudo systemctl restart containerd

 

Verify that containerd is running:

sudo systemctl status containerd

 

Disable swap:

sudo swapoff -a

Install the dependency packages:

sudo apt-get update && sudo apt-get install -y apt-transport-https curl

 

Download and add the GPG key:

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.27/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

 

Add Kubernetes to the repository list:

cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list

deb [trusted=yes] https://pkgs.k8s.io/core:/stable:/v1.27/deb/ /

EOF

 

Update the package listings:

sudo apt-get update

 

Install Kubernetes packages:

Note: If you get a dpkg lock message, just wait a minute or two before trying the command again.

 

sudo apt-get install -y kubelet kubeadm kubectl

 

Turn off automatic updates:

sudo apt-mark hold kubelet kubeadm kubectl

 

 

Initialize the Cluster

Open port 6443 on the control plane server

Initialize the Kubernetes cluster on the control plane node using kubeadm:

sudo kubeadm init --pod-network-cidr 192.168.0.0/16 --kubernetes-version 1.27.11

 

Set kubectl access:

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

 

Test access to the cluster:

kubectl get nodes

 

Install the Calico Network Add-On

On the control plane node, install Calico Networking:

 

kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml

 

Check the status of the control plane node:

kubectl get nodes

 

Join the Worker Nodes to the Cluster

In the control plane node, create the token and copy the kubeadm join command:

 

kubeadm token create --print-join-command

Note: This output will be used as the next command for the worker nodes.

 

Copy the full output from the previous command used in the control plane node. This command starts with kubeadm join.

 

In both worker nodes, paste the full kubeadm join command to join the cluster. Use sudo to run it as root:

 

sudo kubeadm join...

In the control plane node, view the cluster status:

kubectl get nodes

Note: You may have to wait a few moments to allow all nodes to become ready.