Introduction

Docker is a powerful tool that helps developers build, package, and deploy applications in lightweight, portable containers. Understanding how to create a Dockerfile, build an image from it, and run a container is fundamental to mastering Docker.

This guide will cover:

✅ The three ways to create a Docker image

✅ Docker diff command to check modifications in a container

✅ Dockerfile components and their purpose

✅ Step-by-step process of creating a Dockerfile, building an image, and running a container

Let's dive in! 🚀

1️⃣ Three Ways to Create a Docker Image

There are three methods to create a Docker image:

1️⃣ Pull an image from Docker Hub

• The simplest method is to use an existing image from Docker Hub (e.g., Ubuntu, Nginx, MySQL).

2️⃣ Create an image using a Dockerfile

• This is a declarative approach, where we write a Dockerfile to define our image.

3️⃣ Commit an image from a running container

• If you have modified a running container and want to save it as a new image, you can use the docker commit command.