Kubernetes and Docker

Docker and Kubernetes are two of the most consequential infrastructure technologies of the last decade. They changed how software is built, packaged, and deployed. They are also two technologies that most engineers use before they understand, which creates gaps in knowledge that show up at the worst times: a production outage, a security incident, a performance problem you cannot diagnose. This guide builds understanding from the ground up. Every concept is introduced with the problem it solves. You will understand why containers exist before you understand what they are. You will understand why Kubernetes exists before you understand how it works. By the end, you will know not just how to run these technologies but how to reason about them. Table of Contents The Problem Containers Solve - Why Docker Exists Docker Internals - What a Container Actually Is Images - Building Portable Application Packages Dockerfile - Writing Reproducible Builds Docker Networking - Container Communication Docker Volumes - Managing State Docker Compose - Multi-Container Applications The Problem Kubernetes Solves - Why Orchestration Exists Kubernetes Architecture - The Control Plane and Data Plane Core Kubernetes Objects - Pods, Deployments, Services, ConfigMaps, Secrets Namespaces and RBAC - Multi-Tenancy and Access Control Storage in Kubernetes - Persistent Volumes Ingress - Routing External Traffic Helm - Package Management for Kubernetes Service Mesh - Istio and Advanced Traffic Management AWS Container Services - ECS and EKS Real Architecture Patterns The Problem Containers Solve - Why Docker Exists The Classic Failure Mode A developer builds an application on their MacBook. It works. They hand it to the QA team. It does not work. They hand it to the operations team to deploy to production. It works differently than in QA. "It works on my machine" is not a joke. It is a description of a real, chronic infrastructure problem. The application depends on: A specific version of Python, No