Building a Kubernetes 1.23 Cluster with Kubeadm

Log into the Control Plane Node (Note: The following steps must be performed on all

1. Create configuration file for containerd:

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

1. Load modules: sudo modprobe overlay sudo modprobe br_netfilter

Set 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 new settings:

sudo sysctl --system

Install containerd:

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

Create default configuration file for containerd:

sudo mkdir -p /etc/containerd

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

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

Restart containerd to ensure new configuration file usage:

sudo systemctl restart containerd

Verify that containerd is running.

sudo systemctl status containerd

Disable swap:

sudo swapoff -a

Disable swap on startup in /etc/fstab:

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

Install dependency packages:

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

Download and add GPG key:

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add Kubernetes to repository list:

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

Update 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=1.23.0-00 kubeadm=1.23.0-00 kubectl=1.23.0-00

Turn off automatic updates:

sudo apt-mark hold kubelet kubeadm kubectl

Log into both Worker Nodes to perform previous steps.

1. Initialize the Cluster

Initialize the Kubernetes cluster on the control plane node using kubeadm (Note: This is only performed on the Control Plane Node):

sudo kubeadm init --pod-network-cidr 192.168.0.0/16 --kubernetes-version 1.23.0

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 cluster:

kubectl get nodes

Install the Calico Network Add-On

On the Control Plane Node, install Calico Networking:
kubectl apply -f
https://docs.projectcalico.org/manifests/calico.yaml

Check status of the control plane node:

kubectl get nodes

1. Join the Worker Nodes to the Cluster In the Control Plane Node, create the token and copy the kubeadm join command (NOTE:The join command can also be found in the output from kubeadm init command): kubeadm token create --print-join-command

In both Worker Nodes, paste the kubeadm join command to join the cluster. Use sudo to run it as root:

sudo kubeadm join ...

In the Control Plane Node, view cluster status (Note: You may have to wait a few moments to allow all nodes to become ready):
kubectl get nodes
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