Docker Tutorial for Beginners – Introduction & Getting Started

Introduction

Docker and Containers – Simplified

Docker is a tool that helps you create, deploy, and manage applications inside containers. Containers are lightweight and include everything needed to run an application, such as libraries and dependencies, ensuring the application works the same everywhere.

Here’s a breakdown:

Docker Image: A template or blueprint for your application. It includes the application and everything needed to run it. Container: A running instance of a Docker image. It works like an isolated mini-computer running your application. Docker Hub: A public repository where you can find Docker images to use. Dockerfile: A file containing the instructions to build a Docker image.

Overview

Docker allows developers to package applications into containers—standardized units that contain everything needed to run code, including libraries, system tools, and settings.

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Prerequisites

1. An EC2 Instance running Ubuntu (at least 15GB of storage).If you haven’t set up an EC2 instance yet, check out my previous Blog->Guide to creating an EC2 instance before proceeding.
2. SSH access to the instance.

Part 1: Installing Docker

Step 1: Update the Package Index

Before installing Docker, ensure your package list is up to date.

sudo apt-get update

Step 2: Install Required Dependencies

sudo apt-get install -y ca-certificates curl gnupg lsb-release

Step 3: Add Docker’s Official GPG Key

sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

Step 4: Set up Docker’s Stable Repository

echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Step 5: Install Docker

sudo apt-get update
sudo apt-get install -y docker-ce docker-ce-cli containerd.io

Step 6: Verify Docker Installation

Test if Docker was installed correctly by running a test container:

docker run hello-world

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Part 2: Managing Docker

Step 1: Pulling an Image from Docker Hub

docker pull httpd

Step 2: Running a Container

docker run -itd -p "8080:80" httpd

Step 3: List Running Containers

docker ps

Step 4: Accessing the Container

docker exec -it CONTAINER_ID /bin/bash

Step 5: Stopping a Container

docker stop CONTAINER_ID

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Part 3: Advanced Docker Usage

Creating a Dockerfile

1. Create a Directory for your project:

    mkdir myproject
    cd myproject
   

2. Create a Dockerfile:

    vi Dockerfile
   

3. Add the Following Instructions:

    FROM ubuntu:latest
    RUN apt-get update && apt-get install -y nginx
    CMD ["nginx", "-g", "daemon off;"]
   

4. Build the Docker Image:

    docker build -t mynginx .
   

Volumes and Persistence

To keep data persistent even if the container is deleted, Docker allows you to use volumes:

1. Create a Volume:

    docker volume create myvol
   

2. Run a Container with Volume Mounting:

    docker run -itd -v myvol:/usr/share/nginx/html -p 8080:80 nginx
   

Push an Image to Docker Hub

1. Log in to Docker Hub:

    docker login
   

2. Tag the Image:

    docker tag mynginx yourusername/mynginx
   

3. Push the Image:

    docker push yourusername/mynginx
   

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Conclusion

With this guide, you should be able to install Docker, manage containers, create custom images, and even share them on Docker Hub. Keep practicing and try to create different kinds of applications in Docker containers!

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For more advanced Docker guides and blog posts, visit www.abdulrahmanh.com.