Docker Overview: From LXC Origins to Architecture and Basic Usage

Docker is built on the concept of Linux Containers (LXC), which provide lightweight process isolation without full virtualization, offering benefits such as shared kernel usage, minimal performance overhead, and simplified resource management.

Docker itself is an open‑source application container engine written in Go, allowing developers to package applications and their dependencies into portable, isolated containers that can run on any Linux host.

The Docker architecture consists of several key components: the Docker client communicates with the Docker daemon; the daemon runs as a background service handling requests, jobs, and resource allocation; the Docker server provides the REST API; the engine manages container lifecycles; jobs represent individual tasks such as pulling images or creating containers; the registry stores and distributes images; the graph module tracks image layers; drivers (graphdriver, networkdriver, execdriver) handle storage, networking, and execution; libcontainer provides low‑level container primitives; and the container module represents the running instance.

Typical Docker usage includes installing the engine ( yum install docker -y ), enabling and starting the service, checking the version ( docker version ), pulling images ( docker pull alpine ), listing images ( docker images ), running containers ( docker run -it alpine sh ), managing containers ( docker ps , docker rm -f container_id ), and viewing logs ( docker logs -f container_name ). The article also covers advanced topics such as container networking, resource limits via cgroups, and accessing containers via docker exec -it .

Overall, Docker provides a flexible, lightweight, and portable solution for building, shipping, and running applications across diverse environments, embodying core principles of cloud‑native development and modern operations.