Dockerfile reference (Engine)
Dockerfile reference
Docker can build images automatically by reading the instructions from a Dockerfile. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image. Using docker build users can create an automated build that executes several command-line instructions in succession.
This page describes the commands you can use in a Dockerfile. When you are done reading this page, refer to the Dockerfile Best Practices for a tip-oriented guide.
Usage
The docker build command builds an image from a Dockerfile and a context. The build’s context is the files at a specified location