This guide walks you through enabling user namespaces in Kubernetes, allowing containers to run as root inside the pod while being mapped to a non-root user on the host. This enhances isolation and security, and makes it possible to allow…
HowTo install a Kubernetes Cluster with Dual Stack IPv4/IPv6 Support
In this blog post, I have summarized how I have set up a single-node Kubernetes cluster version 1.32 on a fresh Ubuntu 24.04 with dual-stack IPv4/IPv6 support. Tested with: Ubuntu 24.04 Kubeadm 1.32.3 CRI-O 1.32 Calico 3.29.3 Part 1: Prepare…
Migrate Kubernetes Runtime from Containerd to CRI-O
Why Replace Containerd with CRI-O in Kubernetes? Switching container runtimes again might seem unnecessary after the recent move from Docker to containerd. However, CRI-O offers unique features like enhanced Kubernetes compatibility and improved security. For example, I used CRI-O to test…
Create a Next.js App and Convert It to the App Router with Cursor AI
We will show how to create a Next.js example app and convert it to the app router with the help of the Cursor AI composer. We will also extend the code by adding a new card pointing to this blog…
Kubernetes: POD vertical Scaling – Changing the Resource Limits of PODs without POD Restart
In Kubernetes v1.27, the InPlacePodVerticalScaling feature was introduced as an alpha capability, allowing you to adjust CPU and memory resources of running pods without restarting them. This feature can reduce downtime and make resource scaling more efficient. In this guide,…
Cheat Sheet: How to install Kubernetes via kubadm on Ubuntu 24.04 (and trying to join it as an additional master to an existing cluster)
ChatGPT helped in this task, but some commands did not work immediately, so I had to ask ChatCPT how to fix the errors I encountered. The command presented here leads through the process of installing Kubernetes using kubeadm on a…
Kubernetes horizontal POD Autoscaling – Hello World
For a quick test of horizontal autoscaling of an NginX deployment, we need the following ingredients: a metrics server installation to be able to measure the POD's CPU an nginx deployment with a CPU reservation an auto scaler configuration a…
How I earned the Certified Kubernetes Administrator (CKA) badge – what would I do differently today?
What is the CKA? The Certified Kubernetes Administrator (CKA) certification proves you have hands-on experience managing Kubernetes clusters. How did I learn Kubernetes? Three years ago, I purchased a 4-day classroom Kubernetes Administration course (LFS458) from FastLane. It was not…
Linux Root Terminal on vocon Cloud – How to save your Image and re-launch a Container based on that Image
This blog post shows how you can run and manage your Docker images on vocon Cloud Desktop. We will launch an Ubuntu container, install git software as a root user and create and save the resulting Docker image on Docker…
Creating a StoryBook Hello World @ NextJS with the help of OpenAI based on ChatGPT – Part 1: chatting and creating a new Next.js app
Do we still need blogs, if there is ChatGPT around? I will test the OpenAI version of ChatGPT. In the long run, we intend to create a NextJS Hello World program with StoryBook. In this part, we will start chatting…
Kubernetes Task: assign a POD to a Node via Node Affinity – Cheat Sheet
Here, we show as shortly as possible how we can place a POD on the controlplane node on killerkoda CKA playground: Task: place a POD on the controlplane POD using Affinity Find documentation: kubernetes.io --> Documentation --> Search "affinity" -->…
Kubernetes etcd backup and restore – cheat sheet
This is a cheat sheet on how to perform backup&restore of the etcd server in kubernetes quickly. Test this on Killercoda Play with Kubernetes tl;dr Find reference: https://kubernetes.io --> Documentation --> Search "etcd backup restore" --> you will find: Operating etcd…
Playwright Hello World @ Angular 14
In this step-by-step guide, we will show you how to create your first successful e2e Playwright test for an Angular 14 project. Step 0 (optional): Start Cloud Desktop - or use your own environment If you need a development environment,…
Cheat Sheet: Install non-privileged podman v3 in a CentOS 7 Container
See how you can run a user space podman container inside another non-privileged container. For that, we create a CentOS 7 image with podman v3 installed. We spin up a Kubernetes non-privileged container from this image, and we show that…
How to enter a root shell session to a Container with containerd or CRI-O using ‚runc‘ or ’nsenter‘
The latest version of Kubernetes does not support Docker as a container runtime anymore. That is why many Kubernetes administrators have migrated their cluster's container runtime from docker to another container runtime like containerd or cri-o. Or they will do…
[SOLVED] WebStorm@CentOS Bug: Could not initialize class com.intellij.javascript.debugger.console.jcef.JCE
Do you know the following Error message? Error running 'Angular Application' # <- the name of the Debug Profile might be named differently in your case Could not initialize class com.intellij.javascript.debugger.console.jcef.JCE This happened to us on our WebStorm Cloud Desktop…
Upgrade Kubernetes Cluster – Cheat sheet
This is a cheat sheet created during the last upgrade of a CentOS-based Kubernetes cluster serving Developer's Cloud Desktops to our customers. TLDR; style. The commands are tested on CentOS 7. For Ubuntu, replace sudo yum install -y kubeadm-1.25.4-00 --disableexcludes=kubernetes…
Migrate Kubernetes Runtime from Docker to containerd
Migration of the kubeadm-based Kubernetes from Docker to containerd should be easy. In my case, it wasn't. Wrong information found on the Internet combined with the incompatibility of the used Kubernetes and containerd versions has caused major problems. Fortunately, I…
Hello ngrx/store @ Angular 13
This Angular ngrx/store tutorial will guide you through the steps of creating a hello world program using ngrx/store. After a brief motivation paragraph, we will learn how to use actions and reducers to manipulate stored states. A few unit tests…
WebStorm Cloud Desktop – the Best Javascript IDE in the Browser
WebStorm Cloud Desktop is now available as an installation-free application that runs in your browser. It provides you with JetBrains' well-known integrated JavaScript development environment with additional CPU and RAM and high internet speed. With the arrival of WebStorm Cloud…