Docker
The building blocks
Everything starts here: how an image is built, how a container runs it, and how Compose ties several containers together into one stack. Every page has commands you can paste straight into a terminal.
Images & layers
How a Dockerfile becomes a stack of cached, content-addressed layers.
Dockerfile reference
Every instruction, what it does, and a working example for each.
Multi-stage builds
Why a naive Dockerfile ships too much, and how stages fix it.
Buildx
Multi-platform builds, build secrets, cache mounts, and bake.
Signing & verification
A digest proves what you pulled -- a signature proves who published it.
Running containers
Starting, inspecting, stopping, and cleaning up containers from an image.
Runtime hardening
Dropping capabilities, a read-only filesystem, and the other flags that matter once a container is actually running.
Exit codes
What a container's exit code actually means, and how to find it.
Docker Compose
Defining a multi-service stack in one YAML file and running it as a unit.
Volumes & networking
Persisting data beyond a container's life, and letting containers find each other.
CLI reference
The docker commands you'll actually type, grouped by what they manage.