6.3

6.3 Docker Project Lab - A Simple Web Application Deployment using Docker

Introduction

This hands-on lab is designed to provide you with a practical understanding of Docker by guiding you through the deployment of a simple web application. You'll gain firsthand experience in containerizing an application, illustrating Docker's core functionalities of building, running, and managing containers.

Objectives

Write a Dockerfile for a simple web application.
Build a Docker image for the web application.
Run the web application inside a Docker container.
Access the web application through a web browser.

Lab Steps

Step 1: Creating Your Web Application

Open your terminal in a Linux environment.
Create a directory for your project:

mkdir simple-web-app 
cd simple-web-app`

Use Nano to create an index.html file: nano index.html.

Insert the following HTML code:

<!DOCTYPE html>
<html>
<head>
  <title>My Simple Web App</title>
</head>
<body>
  <h1>Hello, Docker!</h1>
  <p>Welcome to my simple web application deployed using Docker.</p>
</body>
</html>

Save and exit Nano (CTRL+O, CTRL+X).

Step 2: Writing the Dockerfile

In the simple-web-app directory, create a Dockerfile:

nano Dockerfile

Add the following content to define your Docker image:

# Use nginx base image from Docker Hub
FROM nginx:alpine
# Copy the web application to the nginx server
COPY index.html /usr/share/nginx/html/index.html
# Expose port 80
EXPOSE 80

Save and exit Nano.

Step 3: Building Your Docker Image

Build the Docker image from your Dockerfile:
```
docker build -t simple-web-app .
```
This command creates a Docker image named simple-web-app with the web application.

Step 4: Running Your Docker Container

Run your Docker container:

docker run -d -p 8080:80 simple-web-app

This command runs your image as a container, mapping port 8080 on your host to port 80 on the container.

Step 5: Accessing Your Web Application

Test to verify the page is being served:

curl http://localhost:8080

You should see the following output:

<!DOCTYPE html>
<html>
<head>
  <title>My Simple Web App</title>
</head>
<body>
  <h1>Hello, Docker!</h1>
  <p>Welcome to my simple web application deployed using Docker.</p>
</body>
</html>

Summary

In completing this lab, you've successfully containerized and deployed a simple web application using Docker. Starting from writing a Dockerfile to building and running a Docker container, you've experienced the fundamental processes of working with Docker. This lab serves as a practical introduction to Docker, highlighting its potential to streamline application deployment. With these skills, you're well on your way to exploring more advanced Docker functionalities and architectures.