Kubernetes is a powerful container orchestration platform used for automating the deployment, scaling, and management of containerised applications. In this guide, we will walk you through the step-by-step process of installing Kubernetes on Ubuntu 22.04. This cluster configuration includes a master node and worker nodes, allowing you to harness the full power of Kubernetes.
Kubernetes Nodes
In a Kubernetes cluster, you will encounter two distinct categories of nodes:
Master Nodes: These nodes play a crucial role in managing the control API calls for various components within the Kubernetes cluster. This includes overseeing pods, replication controllers, services, nodes, and more.
Worker Nodes: Worker nodes are responsible for providing runtime environments for containers. It’s worth noting that a group of container pods can extend across multiple worker nodes, ensuring optimal resource allocation and management.
Prerequisites
Before diving into the installation, ensure that your environment meets the following prerequisites:
An Ubuntu 22.04 system.
Privileged access to the system (root or sudo user).
Active internet connection.
Minimum 2GB RAM or more.
Minimum 2 CPU cores (or 2 vCPUs).
20 GB of free disk space on /var (or more).
Step 1: Update System Packages
sudo bash -c "apt update & apt upgrade -y && apt autoremove -y"
Install containerd
sudo bash -c "apt install -y containerd"
Step 2: Create the containerd configuration directory
sudo mkdir -p /etc/containerd
Step 3: Generate the containerd configuration file
sudo containerd config default | sudo tee /etc/containerd/config.toml
Step 4: Edit the containerd configuration file
sudo sed -i 's/^\(\s*SystemdCgroup\s*=\s*\)false/\1true/' /etc/containerd/config.toml
Step 5:Disable swap
sudo swapoff -a
Step 6: Edit the sysctl.conf file
sudo sed -i '/\sswap\s/s/^/#/' /etc/fstab
Step 7: bridging, we only need to edit one config file
sudo sed -i 's/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=1/' /etc/sysctl.conf
Step 8: Edit the k8s.conf file, add the line “br_netfilter” to the file
echo "br_netfilter" | sudo tee /etc/modules-load.d/k8s.conf
Step 9: Reboot the system
sudo reboot
Or you can use a script to automate the process
#!/bin/bash
#Update
sudo bash -c "apt update & apt upgrade -y && apt autoremove -y"
# Install containerd
sudo apt install containerd -y
# Create the containerd configuration directory
sudo mkdir /etc/containerd
# Generate the default containerd configuration
containerd config default | sudo tee /etc/containerd/config.toml
# Edit the containerd configuration file
# Within the file, find the line [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
# Underneath that, find the SystemdCgroup option and change it to true
# Save and exit the editor
sudo sed -i 's/^\(\s*SystemdCgroup\s*=\s*\)false/\1true/' /etc/containerd/config.toml
# Disable swap
sudo swapoff -a
# Edit the sysctl.conf file
# Within the file, look for the line #net.ipv4.ip_forward=1
# Uncomment that line by removing the # symbol in front of it
# Save and exit the editor
sudo sed -i '/\sswap\s/s/^/#/' /etc/fstab
#enable bridging, we only need to edit one config file
sudo sed -i 's/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=1/' /etc/sysctl.conf
# Edit the k8s.conf file
# Add the line "br_netfilter" to the file
# Save and exit the editor
echo "br_netfilter" | sudo tee /etc/modules-load.d/k8s.conf
# Reboot the system
sudo reboot
Installing Kubernetes
If something goes wrong with added repository, you can visit this link and check the latest version
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
The next step is to install the packages that are required for Kubernetes. First, we’ll add the required GPG key:
Step 10: Add the Kubernetes GPG key
sudo apt-get install -y apt-transport-https ca-certificates curl gpg
Step 12: Add the Kubernetes repository
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
update the package list
Add the appropriate Kubernetes apt repository. Please note that this repository have packages only for Kubernetes 1.30; for other Kubernetes minor versions, you need to change the Kubernetes minor version in the URL to match your desired minor version (you should also check that you are reading the documentation for the version of Kubernetes that you plan to install).
This is important because the Kubernetes packages are version-specific, and you need to ensure that you are installing the correct version of the packages for your cluster.
# This overwrites any existing configuration in /etc/apt/sources.list.d/kubernetes.list
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
Step 13: Install Kubernetes packages
sudo apt install -y kubelet kubeadm kubectl
Step 14: Hold the Kubernetes packages
sudo apt-mark hold kubelet kubeadm kubectl
Step 15: Enable and start the kubelet service
sudo systemctl enable --now kubelet
Step 16: Open the required ports and configure security groups
sudo iptables -I INPUT 6 -m state --state NEW -p tcp --dport 6443 -j ACCEPT && sudo netfilter-persistent save
Step 17: edit hosts file
echo "132.145.49.32 larablogger.com" | sudo tee -a /etc/hosts
Step 18: Restart the kubeadm service
sudo kubeadm reset
Step 19: Initialize the Kubernetes cluster
sudo kubeadm init --control-plane-endpoint=larablogger.com:6443 --apiserver-advertise-address=10.0.0.89 --node-name=k8s-master --pod-network-cidr=10.244.0.0/16
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
sudo systemctl restart kubelet && sudo systemctl enable kubelet && sudo systemctl restart containerd
sudo mkdir -p /etc/crictl sudo nano /etc/crictl/config.yaml sudo crictl –runtime-endpoint unix:///run/containerd/containerd.sock ps -a
Step 20 Restart services
sudo systemctl restart kubelet && sudo systemctl enable kubelet && sudo systemctl restart containerd
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
and finally if everything is ok you should see the nodes
kubectl get nodes
Now you can join the worker nodes to the cluster
If for some reason the join command has expired, the following command will provide you with a new one:
Step 21: Generate the join command
kubeadm token create --print-join-command
Step 22: List the nodes
###
```bash
kubectl get nodes
