Docker Python Flask Template

Template for creating a Dockerized application using Python, Flask, Docker, and Docker Compose.

Table of Contents

• Prerequisites
• Overview
• Sample Application
• Getting Started
• License

Prerequisites

Ensure you have Docker, Docker Compose, and Python installed.

Overview

This template allows you to create and deploy a Python application using Flask and Docker. Docker Compose is used to build the Docker image, inject environment variables, and act as a starting point to add additional services to your application.

The template contains the following files and directories:

• src/: Directory for source code - will be copied into Docker image
  • src/app.py: Sample Flask application
  • src/hello_world.py: Sample Python script used in Flask app
• default.env: Default environment file for secret management - should be renamed to .env and never checked into source control
• docker-compose.yml: Default Docker Compose file that injects secrets from .env file and builds Docker image specified by Dockerfile
• Dockerfile: Default Dockerfile that copies source code, installs Python dependencies, and runs Flask server
• Makefile: Helper to easily start, stop, and restart app
• requirements.txt: Defines list of Python requirements that are used by the application and will be installed into the Docker image

Sample Application

The sample application is purely a skeleton to build off of. There are two routes defined in the Flask app:

Endpoint	Description
/	Test connection - will return Connected if successful.
/hello/<name>	Invokes a function in the Python script using the provided parameter - will return Hello <name>! if successful.

Getting Started

1. Clone the repository.
2. Copy the default.env file to a new file called .env and populate with your desired port and any secrets
   • This should never be commited into source control - this template is setup to ensure the .env file is excluded from Git
3. Build your Python application in the src directory.
4. Deploy the app by running make up.
5. Navigate to http://<IP_ADDRESS>/<FLASK_PORT> (e.g. http://localhost:5050) in your browser - you should see Connected if successful.
   • IP_ADDRESS is the IP address of the machine running Docker.
   • FLASK_PORT is the port defined in your .env file (default is 5050)
6. Update app with any changes by re-running make up
7. Restart app by running make restart
8. Stop app by running make down

License

This template is made available under a modified MIT license. See the LICENSE file.