Docker Tutorial
Package, run and ship applications in containers: images, Dockerfiles, volumes and Compose
Beginner to Intermediate4 lessonsabout 20 min of reading
This Docker course is for developers who keep hearing "just put it in a container" and want to understand what that actually means. You should be comfortable in a terminal and have run an application locally. You do not need any operations background. Docker Desktop (or Docker Engine on Linux) is the only tool you need to install to follow along.
By the end you will be able to explain the difference between an image, a layer and a container, write a Dockerfile that rebuilds in seconds and runs as a non-root user, keep data safe with volumes, connect containers over a network, and describe a multi-service app in a Compose file with healthchecks and sensible logging. These are the skills teams expect when a job post says "experience with Docker".
The four lessons build on each other. First the mental model (what is inside an image and why containers are not tiny VMs), then the Dockerfile craft that makes images small and fast to rebuild, then the state and configuration side (volumes, networks, environment variables), and finally Docker Compose plus the habits that separate a demo from something you would run for real. When you are ready to run containers across many machines, continue with the Kubernetes course.
Docker lessons
- 1Docker Containers vs Virtual Machines: Images and Layers ExplainedUnderstand how Docker containers differ from virtual machines, what an image and its layers really are, and how to run and inspect your first container.5 min read
- 2Writing a Good Dockerfile: Caching, Multi-Stage Builds and Non-RootWrite a Dockerfile that rebuilds fast and ships small: order layers for caching, use .dockerignore, multi-stage builds and run as a non-root user.5 min read
- 3Docker Volumes, Networks and Environment Config for ContainersKeep data across container restarts with Docker volumes, connect containers by name on a user-defined network, and pass configuration safely.5 min read
- 4Docker Compose and Production Habits: Healthchecks, Logs and ScanningDefine a multi-container app in a Docker Compose file, then add healthchecks, log limits, smaller images and vulnerability scanning before you ship.5 min read
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