As we showed in the introductory tutorial, containers can be built manually.
However, with a Dockerfile, you can describe build steps once and then build a container automatically--any time you want--from source.
Dockerfiles can be viewed as an image representation. They provide a simple syntax for building images and they are a great way to automate and script the images creation. If you are really serious about Docker, you should master the Dockerfile syntax. Let’s start!
If you haven't taken the introductory tutorial, you should do so before starting this.