Dockerfile

Dockerfile is a text file where you define instructions used to create your Docker images, check official Dockerfile Reference documentation: https://docs.docker.com/engine/reference/builder/

For creating this file with instructions usually called Dockerfile you can use the following keywords:

• ADD
• ARG
• CMD, for executing containers. https://docs.docker.com/engine/reference/builder/#cmd
• COPY
• ENTRYPOINT: https://docs.docker.com/engine/reference/builder/#entrypoint
• ENV
• EXPOSE
• FROM https://docs.docker.com/engine/reference/builder/#from
• HEALTHCHECK https://docs.docker.com/engine/reference/builder/#healthcheck (>= Docker 1.12)
• LABEL
• ONBUILD
• RUN: https://docs.docker.com/engine/reference/builder/#run
• SHELL
• STOPSIGNAL
• USER: https://docs.docker.com/engine/reference/builder/#user
• VOLUME, creates a mount point
• WORKDIR

Activities

1. Learn differences between RUN and CMD or ENTRYPOINT: https://stackoverflow.com/a/25150809
2. Read Understand how CMD and ENTRYPOINT interact https://docs.docker.com/engine/reference/builder/#understand-how-cmd-and-entrypoint-interact
3. Learn about start configuration behavior and restart policy
4. Learn how to use .dockerignore file
5. Read Dockerfile best practices https://docs.docker.com/develop/develop-images/dockerfile_best-practices/

Related terms

• Dockerfile examples
• docker build
• docker-compose build, image:, build:, dockerfile:, args:
• Docker Engine release notes
• BuildKit Dockerfile-agnostic builder toolkit
• docker start, docker run
• Buildpack
• .dockerignore
• Makefile

See also

• Dockerfile: FROM, RUN, CMD, ENTRYPOINT, WORKDIR, COPY, ADD, USER, ENV, ARG, HEALTHCHECK, hadolint, LABEL, EXPOSE
• docker build [ --tag | --platform | --help ] FROM, Dockerfile, .dockerignore, requirements.txt, docker build --help, docker tag
• docker-compose, docker-compose.yml: [services | volumes | networks | up | down | restart | logs | create | changelog | version | secrets | config | -v | -h | exec], docker-compose pull, Environment:, Docker-compose.yml examples, .env, release notes, expose:, docker-compose --env-file, services.deploy.resources

https://en.wikiversity.org/wiki/DevOps/Docker/Dockerfile

https://kapeli.com/cheat_sheets/Dockerfile.docset/Contents/Resources/Documents/index