Beginner-Intermediate|10 hours|18 lessons

Docker & Container Fundamentals

A free course covering what containers actually are, how Docker images work, and how to run and debug them in production. Builds on the Linux namespaces and cgroups work, no more magic.

Completely Free

No signup required. Start learning now.

Text-based, no videos

6 modules, 18 lessons

No signup required

What you'll learn

What a container actually is: namespaces, cgroups, and chroot, not a lightweight VM

What Docker really is: dockerd, containerd, runc, and the OCI spec

How image layers and OverlayFS work, and why your image is 2 GB when your app is 50 MB

Dockerfile craft: layer caching, COPY vs ADD, multi-stage builds that cut image size 10×

Container networking and volumes, bridge vs host, bind mounts vs named volumes

Docker Compose for multi-container apps and when it's enough for production

Container security: running as non-root, image scanning, resource limits, health checks

Production debugging: won't start, slow, or broken networking; the flowcharts that work

Curriculum

6 modules · 18 lessons

What Containers Actually Are

The mental model everyone gets wrong, containers are not lightweight VMs, and Docker is not one thing. Start here.

3 lessons

Containers Are Not VMs25 minFREE The Three Primitives: Namespaces, cgroups, chroot30 minFREE What Docker Actually Is30 minFREE

Images

How Docker images actually work: layered, cached, and shipped. Build better ones, ship smaller ones, and stop fighting the daemon.

3 lessons

Image Layers and Union Filesystems30 minFREE Writing a Dockerfile That Doesn't Suck35 minFREE Image Registries30 minFREE

Running Containers

docker run, container networking, and volumes, the three things you do every day, explained in terms of what Docker is actually doing to the host.

3 lessons

The docker run Deep Dive30 minFREE Container Networking35 minFREE Volumes and Data30 minFREE

Docker Compose

Multi-container apps in one YAML file: services, networks, volumes. Enough for development, sometimes enough for production, and a natural bridge to Kubernetes.

3 lessons

Multi-Container Applications30 minFREE Development Workflows with Compose30 minFREE Compose in Production?30 minFREE

Container Security & Best Practices

The defaults are wrong. Run as non-root, scan your images, set resource limits, and add health checks, the baseline that should be on every container you ship.

3 lessons

The Root Problem30 minFREE Image Scanning and Vulnerabilities30 minFREE Resource Limits and Health Checks30 minFREE

Production Docker Debugging

When the container won't start, is slow, or can't reach another container, the flowcharts that get you to root cause without rebuilding the image.

3 lessons

Container Won't Start30 minFREE Container Is Slow30 minFREE Container Networking Issues30 minFREE

About the Author

Sharon Sahadevan

AI Infrastructure Engineer

Building production GPU clusters on Kubernetes. H100s, large-scale model serving, and end-to-end ML infrastructure across Azure and AWS.

10+ years designing cloud-native platforms with deep expertise in Kubernetes orchestration, GitOps (Argo CD), Terraform, and MLOps pipelines for LLM deployment.

Author of KubeNatives, a weekly newsletter read by 3,000+ DevOps and ML engineers for production insights on K8s internals, GPU scheduling, and model-serving patterns.

Start learning now, completely free

6 modules, 18 lessons. No signup, no paywall.