Introduction
In this guide, we will install K3s, a lightweight Kubernetes distribution. Kubernetes is an open-source system for automating the deployment, scaling, and management of containerized applications.
The guide is prepared for the Ubuntu operating system.
Updating the packages
Starting from the updates:
sudo apt update
sudo apt upgrade
Installing Kubernetes
To install the K3s, use:
curl -sfL https://get.k3s.io | sh -
Checking the K3s service status using systemctl to verify if it is running or not, use:
systemctl status k3s
Checking the default Kubernetes objects after the installation of K3s:
sudo kubectl get all -n kube-system
As an output, you should get:
The output shows different objects installed within the Kubernetes cluster.
Modifying the configuration
We have installed K3s using the default setup. However, we can adjust the configuration to get a specific (custom) behavior of the cluster.
A default installation comes with traefik controller. It's an open-source reverse proxy and ingress controller that simplifies the deployment and management of services. For example, this controller is not needed and should be disabled during installation.
The following command can be used to disable the traefik during K3s installation:
curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--disable=traefik" sh -
The same can also be done within the configuration file:
sudo nano /etc/rancher/k3s/config.yaml
Add the following to the file:
disable: traefik
Restart the K3s service:
sudo systemctl restart k3s
Uninstalling Kubernetes
To uninstall Kubernetes (K3s), use:
/usr/local/bin/k3s-uninstall.sh
To verify it was successfully uninstalled, use:
systemctl status k3s
Output:
Conclusion
We have installed a Kubernetes (K3s) cluster on Ubuntu and modified its configuration. When you have Kubernetes installed, you explore various types of objects and their functionalities.
The full list of available flags can be found here: https://docs.k3s.io/cli/server