K8s

CKAD Certification Journey — Part 5: Services & Networking (Where Kubernetes Becomes a Distributed System) Up until now, everything we’ve discussed — Pods, Deployments, Config, Observability — happens inside isolated units. But real systems are not isolated. They communicate. And the moment you introduce communication, you introduce: instability coupling failure propagation latency security risks This is where Kubernetes networking stops being “just configuration” and becomes system design. 🧠 The Fundamental Problem: Pods Are Ephemeral Every Pod in Kubernetes gets its own IP. ...

CKAD Certification Journey — Part 4: Application Environment, Configuration & Security (Where Control Meets Responsibility) By the time you reach this stage, you already know how to: build applications deploy them observe them But here is where things become real engineering: 👉 How you configure and secure your applications determines whether your system is stable, multi-tenant, and safe — or fragile and dangerous. This is not just about features like ConfigMaps or Secrets. This is about understanding how Kubernetes enforces boundaries and behaviour. ...

CKAD Certification Journey — Part 3: Application Observability & Maintenance (The Reality of Running Systems) If deployment is where you introduce change, observability is where you survive that change. And here is the uncomfortable truth: Most engineers don’t fail at Kubernetes because they don’t know how to deploy — they fail because they don’t know how to understand what’s happening after deployment. This article is not a list of tools. It is a practical mental model for diagnosing real systems under pressure. ...

CKAD Certification Journey — Part 2: Application Deployment If Part 1 was about building applications correctly, this part is about something far more dangerous: 👉 Deploying them without breaking production Because here’s the uncomfortable truth: Most Kubernetes outages are not caused by Kubernetes itself — they are caused by how applications are deployed, updated, and scaled. This article is not a glossary. It’s a mental model + practical guide to how deployment actually works in real systems. ...

What Really Happens on a Kubernetes Node (Deep Dive): OverlayFS, containerd, Volumes, and the Hidden Mechanics Most Kubernetes explanations stop at Pods and containers. But the real story — the one that actually helps you debug, optimise, and reason about failures — happens inside the node. This article goes beyond the basics and explains: OverlayFS (and why it matters in real scenarios) containerd internals (beyond “it runs containers”) Image storage and caching Writable layers and their limitations Volume mounting mechanics (bind mounts) The kubelet’s role in orchestrating everything Linux primitives: namespaces & cgroups Where performance and problems actually come from 🧠 The Real Execution Flow When you create a Pod, Kubernetes does NOT “run a container”. ...

CKAD Certification Journey — Part 1: Application Design & Build Achieving the Certified Kubernetes Application Developer (CKAD) certification has been a rewarding milestone in my journey as a developer. This blog series is structured into five parts, each covering a key domain of the CKAD curriculum: Application Design & Build (this article) Application Deployment Application Observability & Maintenance Application Environment, Configuration & Security Services & Networking This first part focuses on the foundations of building applications for Kubernetes — understanding containers, how they are built and distributed, and how Kubernetes runs them efficiently. ...

From Local Dockerfile to Kubernetes Deployment: A Complete Step-by-Step Guide Introduction In modern cloud-native development, containerisation and orchestration are fundamental skills. This guide walks you through the entire lifecycle of a simple Python application — from building a Docker image locally, storing it in GitHub, pushing it to Docker Hub, and finally running it in a Kubernetes cluster from another virtual machine. By the end of this tutorial, you will have a fully reproducible workflow that mirrors real-world DevOps practices. ...