Why is Docker such a popular tool for application containerization?

Docker became popular due to the following key advantages:

• Ease and speed of deployment: containers start quickly and use fewer resources compared to virtual machines.
• Application isolation: each application runs in its own container with its dependencies, preventing conflicts.
• Portability: containers can be run on any system with Docker, providing a consistent environment for development, testing, and production.
• Version and image management: Docker allows creating images that can be stored, distributed, and rolled back.

Example Dockerfile for a Python application:

FROM python:3.9-slim
WORKDIR /app
COPY requirements.txt ./
RUN pip install -r requirements.txt
COPY . .
CMD ["python", "app.py"]