Posts

On the last Friday of July (this year, July 25, 2025), we celebrate System Administrator Appreciation Day to honour these silent guardians of our digital world. Sending good vibes and a massive high‑five to all the sudo scientists pulling on‑call rotations and hanging out in those late‑night Slack channels, keeping the world online. You’re the heartbeat of every business out there 😻 ref: https://sysadminday.com/

Proposal: Migration from Cluster Autoscaler to Karpenter for EKS Cluster Overview The most common approach to scaling Kubernetes clusters in AWS is to use Cluster Autoscaler (CA), which automatically adjusts the number of nodes based on pod resource requirements. However, CA has limitations when managing mixed-instance Auto Scaling Groups (ASG), leading to inefficiencies in scaling down nodes. To address these issues, we propose migrating to Karpenter, a Kubernetes-based node provisioning solution that offers advanced features like direct EC2 provisioning and customizability. This document outlines the technical steps, pros and cons, and migration plan for transitioning from Cluster Autoscaler (CA) to Karpenter in an EKS environment. The change aims to address inefficiencies in scaling down mixed-instance Auto Scaling Groups (ASG) and improve provisioning flexibility by leveraging Karpenter’s advanced capabilities. ...

Manually setting up PHP applications can be tedious and error-prone. By using AWS services and Terraform, we can automate our infrastructure setup, providing a scalable and secure environment for our PHP blog. This guide will walk we through a basic architecture, considerations, and common pitfalls. At the end, we’ll be able to host our blog with minimal effort and manage it like a pro. The Architecture The setup consists of the following components: ...

Optimizing Vault Costs with serviceaccount_name for Identity Aliases Hashicorp Vault SaaS bills on client usage, and a client is everything from a user to a machine. More on this here. The problem is that when a developer removes a chart and redeploys it, vault will count the Kubernetes ServiceAccount as a distinct new app, which isn’t quite true, because it’s the same app we had before and we were billed for. ...

A Beginner’s Guide to DNS - From Domain Purchase to Establishing Your Online Presence The Common Query: What Happens After Buying a Domain? As an IT professional with a sysadmin background and cloud infrastructure focus, I often get DNS-related questions from programmers and colleagues who are just starting out with their own websites. One common confusion that arises post-purchase is about the role and setup of DNS hosting. This post aims to clarify these concepts, using my own experience with setting up https://cloudcat.digital as a practical example. ...