Docker Crash Course
“Docker containers wrap a piece of software in a complete filesystem that contains everything needed to run.” - Solomon HykesDocker killed the “it works on my machine” problem. Before Docker, deploying software was a nightmare of environment mismatches, dependency hell, and configuration drift. Containers changed everything. This course takes you from zero to production-ready Docker skills.
Why Docker Matters
Consistency
The “it works on my machine” problem is dead. Containers guarantee identical environments everywhere.
Isolation
Each container is a fortress. No more dependency conflicts or “but I have Python 2.7 installed” disasters.
Efficiency
Containers share the OS kernel. We are talking MBs instead of GBs, seconds instead of minutes.
Portability
Build once, run anywhere. Your laptop, staging server, production cluster, any cloud provider.
The Story Behind Docker
2013: Solomon Hykes presented Docker at PyCon. It changed everything. The Problem:- “Works on my machine” syndrome
- Complex deployment processes
- Environment inconsistencies
- Slow VM startup times
- Lightweight (MBs vs GBs)
- Fast startup (seconds vs minutes)
- Consistent environments
- Easy to share and deploy
- Millions of applications
- Every major cloud platform
- CI/CD pipelines worldwide
- Kubernetes (built on containers)
What You’ll Learn
1
Fundamentals
Images, containers, Docker architecture, essential commands. The foundation everything else builds on.
Start Here
2
Internals Deep Dive
Namespaces, cgroups, union filesystems, the Docker daemon. If you love understanding how things actually work, this one is for you.
Explore Internals
3
Building Images
Dockerfile mastery, layer caching, multi-stage builds. Craft production-grade images that are secure and optimized.
Build Images
4
Networking and Volumes
Container networking, bridge vs host vs overlay, port mapping, data persistence. How containers talk to each other and the outside world.
Learn Networking
5
Docker Compose
Multi-container applications, service orchestration, development workflows. The bridge between Docker and Kubernetes.
Use Compose
6
Best Practices
Security hardening, image optimization, production deployment patterns. Ship with confidence.
Best Practices
Docker vs Virtual Machines
| Feature | Docker Containers | Virtual Machines |
|---|---|---|
| Size | MBs | GBs |
| Startup | Seconds | Minutes |
| Performance | Native | Overhead |
| Isolation | Process-level | Full OS |
| Resource Usage | Shared kernel | Separate OS |
When to use VMs: Different OS, strong isolation, legacy apps
Course Structure
Module 1: Fundamentals (2-3 hours)
Docker architecture, images vs containers, the container lifecycle, essential commands you will use daily.Module 2: Internals Deep Dive (2-3 hours)
How Docker actually works under the hood. Namespaces, cgroups, union filesystems, OCI specification. If you love internals, continue. If not, skip to Module 3.Module 3: Building Images (2-3 hours)
Dockerfile mastery, layer caching strategies, multi-stage builds, building for production.Module 4: Networking and Volumes (2 hours)
Bridge networks, overlay networks, port mapping, volumes vs bind mounts, data persistence patterns.Module 5: Docker Compose (2 hours)
Multi-container applications, service dependencies, development vs production configs.Module 6: Best Practices (2 hours)
Security hardening, rootless containers, image scanning, production deployment patterns.Ready to master Docker? Start with Docker Fundamentals or jump straight to Internals Deep Dive if you want to understand how containers really work.