Kubernetes Foundations — Architecture, Components & kubectl

Table of Contents Why Kubernetes Exists Cluster Architecture Control Plane Worker Node Components kubectl Local Cluster Setup Cheat Sheet Why Kubernetes Exists Before Kubernetes, running containers in production meant: SSH into servers, start and stop containers by hand, write fragile shell scripts for restarts, and scale by spinning up machines one by one. Kubernetes is a container orchestration system. It solves five problems that every team hits at scale. 🔴 Problem 1 — Single Point of Failure Without Kubernetes: [App] ──► [Server A] ──✕──► App is DOWN until someone manually fixes it With Kubernetes: ┌──► [Node A] ──✕── dies [App] ─────┤──► [Node B] ✓ still running └──► [Node C] ✓ still running K8s auto-reschedules pod from A → B or C Kubernetes detects the dead node and automatically reschedules all pods to healthy ones. No pager. No SSH. 📈 Problem 2 — Manual Scaling Without Kubernetes: Traffic spike → someone notices → SSH → docker run ×10 → 20 minutes wasted With Kubernetes: Traff