🚀 Day-8: Namespaces, Labels, Selectors, ConfigMaps & Secrets | Real-World Project + Interview Qs 🔥

Description

Welcome to Day-8 of the Kubernetes Zero to Hero Series by Tech With Diwana 💙 In this 24-minute masterclass, you’ll learn how Namespaces, Labels, Selectors, ConfigMaps, and Secrets work together to build a real-world browser application on Kubernetes. We’ll not just learn theory — we’ll build and deploy a live app using all objects we covered from Day-1 to Day-8 so you can finally understand how everything connects inside a Kubernetes cluster. ⚡ No textbook talk — just pure practical learning + interview-focused explanations. 🧠 What You’ll Learn Today ✅ Understand Namespaces — isolate multiple environments (Dev, QA, Prod) ✅ Master Labels & Selectors — connect Deployments and Services correctly ✅ Create & Mount ConfigMaps — serve configuration dynamically ✅ Secure data with Secrets — protect credentials safely ✅ Understand why Dry-Run YAML must be edited manually ✅ Learn real-world interview scenarios and how to answer them ✅ Combine everything from Day-1 → Day-8 into one working demo 🧩 GitHub Repository (All YAMLs + README + Auto Demo Script) 📂 Complete Source Code + Theory + Demo: 👉 https://github.com/techwithdiwana/kubernetes-zero-to-hero/tree/main/day8_Namspaces-lables-selector-configmap-secret 🧠 Real Interview Questions Covered 1️⃣ Why do we use Namespaces in production clusters? 2️⃣ Why does a Service show 0 endpoints? 3️⃣ What happens if you change ConfigMap but pod still uses old data? 4️⃣ How to inject database credentials safely? 5️⃣ How can a pod know its namespace automatically? 🕒 Timestamps (Video Duration: 24:00 Minutes) | Time | Topic | | ----- | ------------------------------------------------------------------------------------- | | 00:00 | 🔥 Intro + Hook (Real Interview Scenarios) | | 01:40 | ⚙️ Setup & “Dry-Run → YAML → Apply” Rule | | 02:30 | 🧱 Namespace — Isolate Your Cluster Resources | | 04:00 | ⚙️ ConfigMap — Serve HTML File via Nginx | | 07:00 | 🏗️ Deployment — Labels, Selectors, and Volumes Explained | | 10:00 | 🌐 Service — Connecting Pods Using Labels & Selectors | | 13:00 | 🔒 Secrets — Safely Injecting Sensitive Data | | 16:00 | ⚠️ Why Dry-Run YAML Needs Edits (Limitations Explained) | | 18:00 | 💡 Live Browser Demo (Payments App on [http://localhost:8080](http://localhost:8080)) | | 20:00 | 🧩 Day-1 → Day-8 Full Recap | | 22:00 | 🧠 Interview Questions + Troubleshooting Tips | | 23:00 | 🎯 Outro + Day-9 Sneak Peek (Ingress + Services) | 🧑‍💻 Project Setup (Demo Reproducible) All YAMLs are included in the GitHub repo and a one-click run_day8_demo.bat script is provided. Run it → Wait for pods → Open your browser → Visit: 🌐 http://localhost:8080 You’ll see a Payments App rendered directly from a ConfigMap inside Kubernetes! 🎉 🧹 Cleanup Command 🔗 Next Episode 👉 Day-9: Services & Ingress — Routing External Traffic into Kubernetes 📅 Premiere Soon on Tech With Diwana 💙 Credits Created & Presented by: Tech With Diwana 🎓 “Learn | Build | Automate | Crack the Interview” #Kubernetes #DevOps #TechWithDiwana #ZeroToHero #Namespaces #Labels #ConfigMap #Secrets #Selectors #KubernetesTutorial #KubernetesForBeginners