Docker & Kubernetes
Containers and orchestration explained from first principles — what problem they actually solve, how Docker works under the hood, and how Kubernetes takes container apps to production at scale.
Written byRohan Sharma
Containers Fundamentals
3 lessons- 10 min read
Why containers exist
The deployment problem containers were built to solve, told through what came before them.
- 11 min read
Namespaces and cgroups: how isolation actually works
The two Linux kernel features that make containers possible, explained without hand-waving.
- 8 min read
Docker's architecture — daemon, client, and registries
How the docker command, the background daemon, and image registries fit together.
Containers Fundamentals Quiz
6 questions
Docker Essentials
4 lessons- 9 min read
Images vs containers
The single most important distinction in Docker, explained with a class-and-object analogy and real commands.
- 8 min read
Everyday container commands
Logs, exec, inspect, and the debugging workflow you'll use on every container you ever run.
- 12 min read
Writing your first Dockerfile
Every Dockerfile instruction explained line by line, building a real Node.js app image from scratch.
- 9 min read
Multi-stage builds
How to keep production images small by separating build-time tools from what actually ships.
Docker Essentials Quiz
7 questions
Data & Networking
3 lessons- 8 min read
Why containers need volumes
What happens to data when a container is removed, and why the writable layer alone isn't good enough for anything that matters.
- 10 min read
Docker networking and how containers talk to each other
Bridge networks, container DNS, and how two containers actually find and reach each other.
- 7 min read
Environment variables and configuration
Keeping images generic by injecting configuration at runtime instead of baking it in.
Data & Networking Quiz
6 questions
Images & Registries
3 lessons- 8 min read
Tagging and publishing images
Naming conventions, pushing to Docker Hub, and why tagging strategy matters more than people expect.
- 8 min read
Image security and hygiene
Vulnerability scanning, running as a non-root user, and other habits that separate hobby images from production-ready ones.
- 7 min read
Reducing image size and layer count
Practical techniques for keeping images lean beyond just choosing a small base image.
Images & Registries Quiz
6 questions
Compose & Workflows
3 lessons- 10 min read
Introducing Docker Compose
Replacing a pile of manual docker run, network, and volume commands with one declarative YAML file.
- 9 min read
A practical local development workflow with Compose
Live-reloading your app code inside a container, healthchecks, and multiple Compose files for different environments.
- 8 min read
When Docker alone stops being enough
The real-world operational problems that plain Docker and Compose don't solve, and why they lead directly to Kubernetes.
Compose & Workflows Quiz
6 questions
Kubernetes Fundamentals
4 lessons- 12 min read
Kubernetes cluster architecture
Control plane, nodes, and the components that make up a Kubernetes cluster, explained piece by piece.
- 10 min read
Pods, the smallest deployable unit
Why Kubernetes wraps containers in Pods instead of running them directly, and your first real YAML manifest.
- 11 min read
Deployments and self-healing
How Deployments and ReplicaSets keep the right number of Pods running automatically, and how rolling updates work.
- 10 min read
Services and stable networking
How Kubernetes gives a moving set of Pods one stable address, and the Service types you'll actually use.
Kubernetes Fundamentals Quiz
8 questions
Kubernetes Workloads
4 lessons- 9 min read
ConfigMaps and Secrets
Injecting configuration and sensitive values into Pods without baking them into images, the Kubernetes way.
- 9 min read
StatefulSets for databases and stateful apps
Why Deployments aren't a good fit for databases, and what StatefulSets do differently.
- 7 min read
Jobs and CronJobs
Running work to completion instead of continuously — batch tasks, migrations, and scheduled jobs.
- 10 min read
Resource limits and health probes
Requests and limits for CPU/memory, and the three types of health probes that let Kubernetes know if a Pod is actually working.
Kubernetes Workloads Quiz
8 questions
Production Kubernetes
5 lessons- 10 min read
Namespaces, Ingress, and routing traffic in
Organizing a cluster with Namespaces, and exposing multiple services under one domain with Ingress.
- 8 min read
RBAC: controlling who can do what
Roles, RoleBindings, and ServiceAccounts — how Kubernetes decides what a user or Pod is allowed to do.
- 8 min read
Observability — logs, metrics, and the metrics pipeline
Why kubectl logs stops being enough at scale, and the standard tools that fill the gap.
- 10 min read
Autoscaling and wrapping up
Horizontal Pod Autoscaling, cluster autoscaling, and how everything in this course fits together.
- 10 min read
Docker & Kubernetes cheat sheet
Every command from this course in one place — Docker, Compose, and kubectl — organized by task, for quick reference.
Production Kubernetes Quiz
8 questions
Assessments
9 quizzesContainers Fundamentals Quiz
Containers Fundamentals · 6 questions
Docker Essentials Quiz
Docker Essentials · 7 questions
Data & Networking Quiz
Data & Networking · 6 questions
Images & Registries Quiz
Images & Registries · 6 questions
Compose & Workflows Quiz
Compose & Workflows · 6 questions
Kubernetes Fundamentals Quiz
Kubernetes Fundamentals · 8 questions
Kubernetes Workloads Quiz
Kubernetes Workloads · 8 questions
Production Kubernetes Quiz
Production Kubernetes · 8 questions
Docker & Kubernetes Final Assessment
Final assessment · 22 questions