Docker Hello World

Welcome aboard the Docker journey! This beginner-friendly guide dives into the essentials, explaining key concepts and guiding you through installation on Linux, Windows, and macOS.

Docker empowers developers. It tackles common challenges and streamlines the software development cycle, making it an invaluable tool for your arsenal.

Ready to set sail? We'll start with a classic "Hello World" example to introduce you to the basics. Buckle up and let's get building!

Prerequisite

A basic level of understanding of OS and containerization is required to fully understand the concepts explained during 'docker hello world'.

Basic Terminologies

A lot of different objects work together to run an application inside Docker. An application requires objects such as - Docker Images for the application code, Docker Containers to run the application, and Docker Registries to save and download Docker Images.

Docker Container

It is the place where the docker runs an image. You can think of it in this way as well for simplicity: Images become containers when they run on Docker Engine.

Docker Image

It is a lightweight, executable package that consists of everything needed to run an application: code, libraries, third-party dependencies, environment variables, and configurations.

Dockerfile

It is a document that consists of all the commands a user wants to call on the command line to build an image.

Docker Installation in CentOS/Redhat

To be able to run the Docker Engine, you'll need to have a supported version of CentOS. The latest version is recommended.

In order to install the engine, we'll first set up the docker repository and then use the repository to install the docker engine.

Repository Setup

Below commands would install the yum-utils package and set up the repository.

Installation of Engine

The below command would install the latest version of Docker Engine, containers, and Docker Compose.