Learn How To Create A Dockerfile in 203 Seconds

Learn in 162 seconds why you need Docker, what it is all about, and how the three core components work together.

• What is a Dockerfile?
• How do I create my first Dockerfile?
• What Commands do I need?
• How do the commands work together?
• How does the cache function work?
• How do layers work?

FROM <base-image> – Set the base image for your Dockerfile (e.g. FROM node:18-alpine). You can search for them on Docker Hub

COPY <path-on-host-file-system> <path-in-image-file-system> – Copy files and directories into the final Docker image (e.g. COPY ./package* .).

RUN <command> – Run a command inside your Docker image, but on build time (e.g. RUN npm install)

EXPOSE <port> – Glorified comment telling a developer which ports are used in this Docker image (e.g. EXPOSE 3000)

CMD [<command>, <option>, <...>] – This is the command that will be executed when the container is started (e.g. CMD ["node", "./build/server.js"])