Simple File Upload Server

A lightweight Flask-based file upload and download server with a modern UI. Perfect for temporary file sharing and mobile app log uploads.

Features

• Clean, modern UI for file downloads
• Mobile-friendly upload endpoint
• Secure 6-digit alphanumeric code system
• Automatic file cleanup
• Configurable download limits and expiry times
• User-friendly error pages
• Docker support

Architecture

Built using the MVC design pattern:

• Model: File metadata management (code, path, downloads, expiry)
• View: Modern HTML templates with client-side validation
• Controller: Upload/download logic with error handling

Getting Started

Local Development

# Create and activate virtual environment
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

# Run the server
python src/app.py

Docker Deployment

# Build the image
docker build -t file-upload-server .

# Run the container
docker run -p 7777:7777 -v $(pwd)/tmp:/app/tmp file-upload-server

API Endpoints

POST /upload

Upload a file and receive a download code.

Form Fields:

• file: File to upload (required)
• max_downloads: Maximum download count (optional, default: 1)
• expiry_hours: Hours until expiry (optional, default: 24, max: 24)

Response:

{
  "code": "ABC123"
}

GET /download/{code}

Download a file using a 6-character code.

Responses:

• 200: File download starts
• 404: File not found with specific error page for:
  • Invalid code
  • Expired file
  • Download limit reached
  • File no longer exists

Security Notes

• Files are automatically deleted after:
  • Reaching download limit
  • Exceeding expiry time
  • Server restart (temporary storage)
• No file execution permissions in upload directory
• Secure filename handling

Configuration

All configuration is handled through environment variables:

• UPLOAD_FOLDER: Upload directory path (default: tmp/uploads)
• MAX_CONTENT_LENGTH: Maximum file size (default: 16MB)
• DEBUG: Enable debug mode (default: False)

Contributing

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request