Docker — Overview¶

Docker is a container platform and engine used to build, run, and ship containerized applications. It runs Docker "images" as containers — a running instance of an image, isolated from the host OS at the process/filesystem level rather than fully virtualized like a VM.

Each Docker image is built from a base image (commonly something lightweight like Alpine or Ubuntu, purpose-built for containers) plus a set of instructions written in a Dockerfile — a plain-text file listing every command needed to assemble the image, starting with a FROM instruction that defines which base OS/image to build on top of.

Images are typically pulled from Docker Hub, a remote image registry (the container-world equivalent of GitHub for Git repositories). Once an image has been pulled once, Docker caches it locally and checks the local cache before trying to download it again.

In this section¶

Page	Description
Commands	Core Docker CLI reference — inspecting containers/images, networking, and Docker Compose.
Security	Three real-world Docker container-escape and RCE vulnerabilities, with attack breakdowns.
Hardening	Protecting the Docker daemon, resource limits, privileged containers, image review, and compliance scanners.
Tools	Notable Docker security tooling.