Docker Interview Mastery: 200+ Real-World Q&A & Commands (2025 Edition)

The Ultimate Docker Interview Cheat Sheet (200+ Q&A)

Containers are the backbone of modern tech, but explaining them in an interview is harder than it looks.

You know how to run docker run, but can you explain exactly how Docker networking works? Can you debug a container that keeps crashing? Or explain the difference between an Image and a Container without sounding like a robot?

I wrote Docker Interview Mastery because most guides are too academic. They give you definitions, but they don't tell you what hiring managers actually want to hear.

This guide packs 200+ real-world questions covering everything from the basics to advanced production scenarios. Just like my Terraform guide, I use a simple 3-step formula:

1. Simple Explanation: No complex words. Just the concept in plain English.
2. The Command/Code: The exact syntax you need to know.
3. "How to Answer": A ready-to-use script you can memorize to sound like a Senior Engineer.

Why You Need This Book

1. Real Scenarios: Learn how to handle "Works on my machine" issues, optimize huge images, and manage persistent data (Volumes) so you don't lose files.
2. Command Mastery: Don't just memorize flags. Understand when to use docker exec, docker inspect, and docker-compose to fix real problems.
3. Security Focus: Essential questions on scanning images for vulnerabilities and running non-root containers, huge topics for 2025 interviews.
4. Orchestration Ready: Prepares you for the next step (Kubernetes) by solidifying your understanding of Docker Swarm and networking.

Whether you are a developer, a tester, or a DevOps engineer, this book bridges the gap between "I've used Docker" and "I'm an expert in Containerization."