Building Enterprise JavaScript Applications

Overview of a Dockerfile

A Dockerfile is a text file, where each line consists of an instruction followed by one or more arguments:

INSTRUCTION arguments

There are many types of instructions. Here, we will explain the most important ones.

For a complete reference of all instructions and arguments in a valid Dockerfile, refer to the Dockerfile reference at docs.docker.com/engine/reference/builder/:

• FROM: This specifies the base image, which is the Docker image we are basing our own image on. Each Dockerfile must have a FROM instruction as the first instruction. For example, if we want our application to run on an Ubuntu 18.04 machine, then we’d specify FROM ubuntu:bionic.
• RUN: This specifies the command(s) to run at build time, when we run ...