Cat Facts 🐱

A lightweight multi-container application that combines cat facts with dog images for fun, random content displays.

Overview

This application consists of two services:

• Worker: Fetches cat facts from the Cat Facts API and random dog images from the Dog CEO API, storing them in a MySQL database every minute
• Facts Frontend: A Flask web interface that displays random cat fact and dog image combinations from the database

Architecture

┌─────────────┐
│   Worker    │──► Fetches data every 60s
│  (Python)   │    from external APIs
└──────┬──────┘
       │
       ▼
  ┌─────────┐
  │  MySQL  │
  │Database │
  └────┬────┘
       │
       ▼
┌─────────────┐
│   Facts     │──► Displays random
│ Frontend    │    fact + image pairs
│  (Flask)    │
└─────────────┘

Prerequisites

• Docker
• Docker Compose (recommended) or individual container orchestration
• MySQL database

Environment Variables

Both services require the following MySQL connection parameters:

Variable	Description	Example
DB_HOST	MySQL host address	mysql
DB_USER	Database username	catfacts_user
DB_PASSWORD	Database password	secure_password
DB_NAME	Database name	catfacts_db

Running the Application

With Docker

Build the images:

# Build worker
cd worker
docker build -t catfacts-worker .

# Build facts frontend
cd ../facts
docker build -t catfacts-facts .

Run the containers:

# Start MySQL
docker run -d \
  --name catfacts-mysql \
  -e MYSQL_ROOT_PASSWORD=rootpassword \
  -e MYSQL_DATABASE=catfacts_db \
  -e MYSQL_USER=catfacts_user \
  -e MYSQL_PASSWORD=secure_password \
  mysql:latest

# Start worker
docker run -d \
  --name catfacts-worker \
  --link catfacts-mysql:mysql \
  -e DB_HOST=mysql \
  -e DB_USER=catfacts_user \
  -e DB_PASSWORD=secure_password \
  -e DB_NAME=catfacts_db \
  catfacts-worker

# Start facts frontend
docker run -d \
  --name catfacts-facts \
  --link catfacts-mysql:mysql \
  -e DB_HOST=mysql \
  -e DB_USER=catfacts_user \
  -e DB_PASSWORD=secure_password \
  -e DB_NAME=catfacts_db \
  -p 80:80 \
  catfacts-facts

Access the application at http://localhost

Database Schema

The worker automatically creates the following table structure:

CREATE TABLE IF NOT EXISTS data (
    id INT AUTO_INCREMENT PRIMARY KEY,
    fact LONGTEXT,
    image LONGTEXT
);

How It Works

1. Worker Service:

   • Runs scheduled jobs every 60 seconds
   • Fetches a random cat fact from catfact.ninja
   • Fetches a random dog image URL from dog.ceo
   • Stores the pair in the MySQL database
   • Includes health checks for database connectivity and frontend availability

2. Facts Frontend:

   • Provides a web interface at the root path (/)
   • Queries the database for a random cat fact + dog image pair
   • Renders an HTML template displaying both

API Dependencies

• Cat Facts API - Provides random cat facts
• Dog CEO API - Provides random dog images

Tech Stack

• Backend: Python 3.12, Flask
• Database: MySQL
• Containerization: Docker
• Dependencies:
  • mysql-connector-python for database operations
  • requests for API calls
  • schedule for job scheduling

Development

To run locally without Docker:

1. Install dependencies:

   pip install -r facts/app/requirements.txt
   pip install -r worker/app/requirements.txt

2. Set environment variables for database connection

3. Run the worker:

   python worker/app/worker.py

4. Run the facts frontend:

   cd facts/app
   flask run

License

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

Contributing

Contributions are welcome! Feel free to submit issues or pull requests.