A free, self-paced textbook in 7 chapters. Read a chapter, then drill it with the 51 companion flashcards using spaced repetition.
A container is a lightweight, standalone, executable package that bundles an application together with everything it needs to run: the application code, a runtime, libraries, and a...
Under the hood, Docker is built around a long-running background process called the Docker daemon, often invoked as dockerd. The daemon is the engine that creates and manages Docke...
A Dockerfile is a plain-text file containing a series of instructions that Docker uses to build an image automatically. The build is triggered with docker build -t name:tag ., wher...
The docker run command is the primary way to create and start a new container from an image. For example, docker run -it ubuntu bash launches an Ubuntu container with an interactiv...
Containers are designed to be ephemeral, so data written inside them is lost when the container is removed. Docker solves this with volumes, which are persistent storage objects ma...
Most real applications are not a single container but a collection of cooperating services such as a web server, an application server, and a database. Docker Compose is a tool for...
Security is a recurring concern when packaging and running shared workloads. Docker Content Trust, abbreviated DCT, is a mechanism that signs images with cryptographic keys so that...