composedemo

Docker Compose Flask & Redis App

This project demonstrates a simple Python web application built with Flask and Redis, using Docker Compose to set up a multi-container architecture.

Project Structure

composedemo/
│
├── app.py                # Flask application
├── Dockerfile            # Dockerfile to build the web app
├── docker-compose.yml    # Docker Compose configuration
└── requirements.txt      # Python dependencies

Prerequisites

• Docker installed on your machine.
• Docker Compose installed.

Getting Started

Follow these steps to set up and run the project locally.

1. Clone the Repository

git clone https://github.com/LahcenEzzara/composedemo.git
cd composedemo

2. Define the Flask Application

The main Flask application logic is in app.py. It uses Redis to count the number of times the page has been accessed.

3. Define Dependencies

The requirements.txt file lists the necessary dependencies for the Flask app:

flask
redis

4. Build and Run the Containers

Use Docker Compose to build and run the application:

docker compose up

The application will be accessible at http://localhost:8000. Every time you refresh the page, the counter increments.

5. Stop the Application

To stop the running containers, use the following command:

docker compose down

Updating the Application

The docker-compose.yml file includes a bind mount that allows live updates to the code. Any changes made to the app.py file will automatically apply to the running container without needing to rebuild the image.

If you modify the code, simply refresh the page to see the changes:

return 'Hello from Docker! I was here {} times.\n'.format(count)

File Descriptions

app.py

A simple Flask application that connects to Redis to count the number of hits on the page.

Dockerfile

Defines how to build the Docker image for the Flask application:

• Uses Python 3.7 Alpine.
• Installs necessary dependencies from requirements.txt.
• Exposes port 5000 for the Flask app to run.

docker-compose.yml

Sets up two services:

• web: Runs the Flask application.
• redis: Uses the official Redis Alpine image.

requirements.txt

Specifies the Python dependencies for the Flask app:

• flask
• redis

Rebuild the Application

If you need to rebuild the application after making changes, you can do so with:

docker compose up --build

License

This project is open source and available under the MIT License.

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Happy coding! 🎉

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