Building a Kubernetes 1.27 Cluster with kubeadm

Install Packages

Control Pane Node

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-get update && sudo apt-get install -y containerd.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 -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add Kubernetes to the repository list:

cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list 
deb https://apt.kubernetes.io/ kubernetes-xenial main 
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=1.27.0-00 kubeadm=1.27.0-00 kubectl=1.27.0-00

Turn off automatic updates:

sudo apt-mark hold kubelet kubeadm kubectl

Worker Node

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-get update && sudo apt-get install -y containerd.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 -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add Kubernetes to the repository list:

cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list 
deb https://apt.kubernetes.io/ kubernetes-xenial main 
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=1.27.0-00 kubeadm=1.27.0-00 kubectl=1.27.0-00

Turn off automatic updates:

sudo apt-mark hold kubelet kubeadm kubectl

Initialize the Cluster

Control Pane Node

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

sudo kubeadm init --pod-network-cidr 192.168.0.0/16 --kubernetes-version 1.27.0

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

Control Pane Node

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

Control Pane Node

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

kubeadm token create --print-join-command

Worker Node

You can just copy the output from the previous command on the Control Pane Node but add sudo first and it will look similar to this:

kubeadm join 10.0.1.101:6443 --token $token  --discovery-token-ca-cert-hash $discovery-token-ca-cert-hash

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

sudo kubeadm join

Control Pane Node

In the control plane node, view the cluster status:

kubectl get nodes