Containers

cgroups and namespaces — how containers work

Isolation (namespaces) and resource limits (cgroups) — the foundation of containers and systemd.

Docker — containers: running, ports, volumes, networks

Docker runs programs in isolated containers started from images and manages their ports, volumes and networks.

Container images — layers, tags, registries and digests

An image is a read-only stack of layers with files and run settings; Docker creates containers from it.

Dockerfile — an image recipe and docker build

A Dockerfile is an image recipe: base, files, build and start commands; docker build turns it into an image.

docker compose — a container stack in one file

docker compose describes a container stack with network, volumes and variables in compose.yaml and starts it at once.