October 2025 – Technical Scratchpad
2 posts published by luppeng during October 2025| Technical Scratchpad
In a previous post, I explained how to use the Ubuntu Server Netboot Tarball to install the OS via PXE. However, it still requires the sysadmin to have access to the physical machine. This is not scable. By using an Ubuntu autoinstall configuration file, it is possible to automate the entire installation process completely. In this post, I first explain how Ubuntu autoinstall works, and then how have I set it up for my use.| Technical Scratchpad
2 posts published by luppeng during October 2025| Technical Scratchpad
After I created a 4 node k0s cluster, I noticed that some workloads were already provisioned. I believe the intention is to provide a simplified cluster deployment process that is already bootstrapped and ready for receiving its first user workload. Although these pods come with sensible defaults, they can be customized via a config file. I wanted to dive into what these pods are, and what their roles is within the k0s cluster.| Technical Scratchpad
While looking at a Terraform module README, I noticed a chunk of garbled text at the bottom of the page. In some modules, the chunk of garbled text is short, while in others much longer. Initially,…| Technical Scratchpad
For better or worse, one of the desktops in my homelab needed a new installation of the OS but could not read the bootable USB containing Ubuntu Server 24.04. I decided to take this opportunity to get some experience to install Ubuntu Server with using the netboot tarball image instead. This post documents the steps of how I managed to do it.| Technical Scratchpad
I wanted to share two observations that are interesting (to me) when visualizing one of the nodes in my homelab.| Technical Scratchpad
This post is a follow up to my previous post that explains how to set up a Single Node k0s in a LXC Ubuntu Container. I strongly recommend reading/referencing that post to understand the reason beh…| Technical Scratchpad
I woke up one day to Karpenter on AWS EKS throwing this error - "Controller isn't authorized to call ec2:RunInstances", and it took most of my day to figure this one out.| Technical Scratchpad
Prometheus Node Exporter is a tried and tested method to make hardware and OS metrics available as a scrapable endpoint to Prometheus server (or other downstream services/TSDB that support the same format). With OpenTelemetry (OTel) gaining more traction/recognition, I learnt that the OTel Collector's Host Metrics Receiver can also be used to expose host level metrics. However, I wondered if it would be able to make parity in terms of the type/number of metrics it is able to expose to downstr...| Technical Scratchpad
GitLab has clear documentation of how to implement flexible merge request approval workflows. This is useful in code repositories where multiple teams collaborate together to implement an applicati…| Technical Scratchpad
It has been a while since I wrote a similar guide for Apache Atlas v2.3.0. And since I saw that v2.4.0 was released earlier this year, I wanted to give it a try to see if the installation process h…| Technical Scratchpad
Installing and setting up Graphite App on Ubuntu Server 20.04 via the apt repository is not as straightforward as it seems. In this post, I walkthrough the various steps to standup a single Graphit…| Technical Scratchpad
k0s is an open source, all-inclusive Kubernetes distribution, which is configured with all of the features needed to build a Kubernetes cluster (source). On the Quick Start Guide, it only takes 3 s…| Technical Scratchpad
