🐳 Docker

Learn Docker for QA automation, test environments, Selenium Grid, containers, images, volumes, networks and CI workflows.

Master Docker from zero to interview level. Learn how to containerize your test environments, run Selenium Grid and Playwright in Docker, and ensure "it works on my machine" becomes "it works everywhere."

What you can learn on this page

🎯 What is Docker? — Docker is like a shipping container for software. A physical shipping container can carry any cargo — furniture, electronics, food — and any ship, truck, or crane knows how to handle it. Docker containers carry your code and ALL its dependencies, so your app r
⚙️ Docker Installation — Docker Desktop is the simplest way to get started on Windows and Mac. It includes Docker Engine, Docker CLI, Docker Compose, and a nice GUI. On Linux, you install the Docker Engine directly — lighter and faster. Install Docker Desktop on Windows
📦 Core Docker Commands — Docker commands follow a pattern: "docker [object] [action]". Like a library system — you search for books (images), borrow them (pull), read them (run), and return when done (stop/rm). Once you understand this pattern, all commands become intuitive.
🗂️ Dockerfile & Docker Compose — A Dockerfile is like a recipe for building your own Docker image. Docker Compose is like a conductor who starts multiple musicians at once — instead of running 5 separate "docker run" commands, one "docker compose up" starts your entire env
🧪 Docker for QA — Docker transforms QA work. Instead of "install Chrome on every CI agent", one command gives you a fresh browser. Instead of "set up a test database", one command gives you a clean PostgreSQL. Your entire test environment becomes portable, r
💼 Docker Interview Questions