Docker flashcards, generated for you.

Docker is a containerization platform that packages applications with their dependencies into isolated, lightweight containers. It solves the 'works on my machine' problem by ensuring consistent environments across development, testing, and production.

A Docker image is a read-only template with code, runtime, and dependencies. A container is a running instance of an image—it's a live, isolated process with its own filesystem, network, and resource limits.

Starts an nginx container in detached mode (-d), mapping port 8080 on the host to port 80 in the container (-p). The container runs in the background.

A Dockerfile is a script defining how to build a Docker image. Key instructions: FROM (base image), RUN (execute commands), COPY/ADD (add files), WORKDIR (set directory), EXPOSE (document ports), CMD/ENTRYPOINT (default process).

docker-compose orchestrates multi-container applications using a single YAML file. Use it when you need multiple services (app, database, cache) to run together locally or in development, defining networking and volumes in one place.

Use `-v /host/path:/container/path` or named volumes with `docker volume create`. Volumes persist data beyond container lifecycle, enable code hot-reload during development, and share data between containers.

Docker networks enable container-to-container communication. Types: bridge (default, isolated network), host (container shares host network), overlay (for swarm/multi-host), none (no networking). Use custom bridge for DNS service discovery.

Executes an interactive bash shell inside a running container. Use it for debugging, inspecting logs, checking environment variables, or running commands without stopping the container.

ENTRYPOINT defines the main process that always runs; CMD provides default arguments to ENTRYPOINT or a command if no ENTRYPOINT exists. Together: `ENTRYPOINT ['python', 'app.py']` + `CMD ['--debug']` creates a flexible, overrideable default.

Use specific base image tags (not latest), minimize layers with multi-line RUN commands, order instructions by change frequency, use .dockerignore to exclude files, employ multi-stage builds to reduce image size, run as non-root user, and scan images for vulnerabilities.