Experiment to Demonstrate Containerization with Docker

Title: Containerization with Docker

Objective:

The objective of this experiment is to demonstrate containerization using Docker by creating a simple web application and running it inside a Docker container. Containerization allows for the packaging and isolation of applications, making them portable and easily deployable across different environments.

Prerequisites:

• Docker installed on your system

Experiment Steps:

Step 1: Install Docker

1. Download and install Docker for your operating system from the official website (https://www.docker.com/get-started).
2. Verify that Docker is installed correctly by running the following command in the terminal or command prompt:

docker --version

Step 2: Create a Simple Web Application

1. Create a new directory for your web application (e.g., "my-web-app").
2. Inside the "my-web-app" directory, create an index.html file with some simple HTML content (e.g., a "Hello, Docker!" message).

Step 3: Create a Dockerfile

1. In the "my-web-app" directory, create a file named "Dockerfile" (without any file extension).
2. Open the "Dockerfile" in a text editor and define the container configuration:

# Use an existing base image (e.g., nginx) from Docker Hub

FROM nginx:alpine

# Copy the web application files to the container's web root directory

COPY index.html /usr/share/nginx/html/

# Expose port 80 to allow incoming HTTP traffic

EXPOSE 80

Step 4: Build the Docker Image

1. Open a terminal or command prompt.
2. Navigate to the "my-web-app" directory containing the "Dockerfile" and "index.html" file.
3. Build the Docker image using the following command (don't forget the period at the end, indicating the current directory):

docker build -t my-web-app .

Step 5: Run the Docker Container

1. Once the Docker image is built, run a container from it using the following command:

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

• This command maps port 8080 on the host system to port 80 inside the container.

Step 6: Test the Web Application

1. Open a web browser and access the web application by navigating to http://localhost:8080.
2. You should see the "Hello, Docker!" message displayed on the web page.

Step 7: Clean Up

1. Stop the running container by obtaining the container ID and running the following command:

docker stop <container_id>

• Optionally, remove the container and the Docker image from your system:

docker rm <container_id>

docker rmi my-web-app

Conclusion:

In this experiment, we demonstrated containerization using Docker by creating a simple web application and running it inside a Docker container. Docker allows developers to package applications along with their dependencies into lightweight, portable containers, making it easier to distribute and deploy applications consistently across different environments. Containerization is a fundamental technology in modern software development and plays a crucial role in enabling DevOps practices such as Continuous Integration/Continuous Deployment (CI/CD) and improving overall development efficiency.