Docker is a tool that enables containerization, a method of packaging applications and their dependencies into isolated environments. This ensures consistency across development, testing, and production.

Why Use Docker?

1. Portability: Containers run consistently across different environments.
2. Isolation: Separate applications from each other and the host system.
3. Efficiency: Lightweight and faster to start compared to virtual machines.

Example: Dockerfile for a Python App

Here’s a simple Dockerfile to containerize a Python application:

dockerfile
Copy# Use an official Python runtime as the base image
FROM python:3.9-slim
 
# Set the working directory
WORKDIR /app
 
# Copy the application files
COPY . /app
 
# Install dependencies
RUN pip install -r requirements.txt
 
# Run the application
CMD ["python", "app.py"]

Getting Started

1. Install Docker. Build the image: docker build -t my-python-app . Run the container: docker run -p 5000:5000 my-python-app

Docker streamlines workflows, making it an essential skill for modern developers.