Working with Docker Images

Building Images with Dockerfile

0:00

0% complete

LearnStep 1 of 4

Introduction to Dockerfile

Learning Objectives

•Write a Dockerfile
•Understand Dockerfile instructions
•Build custom images

Lesson Outline

LearnStep 1/4

Introduction to Dockerfile

What is a Dockerfile?

A Dockerfile is a text file containing instructions for building a Docker image. It automates the image creation process.

Basic Structure

dockerfile

Common Instructions

FROM: Specifies the base image
RUN: Executes commands during build
COPY: Copies files from host to image
ADD: Like COPY but with extra features
WORKDIR: Sets working directory
ENV: Sets environment variables
EXPOSE: Documents which ports to expose
CMD: Default command to run
ENTRYPOINT: Configures container as executable

Simple Example

dockerfile

Building the Image

bash