🚀 Simple File Sharing (AWS EC2 + S3)

A lightweight Flask web app that lets you upload files to Amazon S3 and instantly get a temporary (pre-signed) download link.
Perfect for sharing files securely without exposing your S3 bucket.

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✨ Features

• 📤 Upload files directly from your browser
• 🔒 Files are stored in a private S3 bucket
• ⏱️ Generates pre-signed download links with expiration
• ⚡ Deployable on AWS EC2 in minutes
• 🐍 Simple Python + Flask stack

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🛠️ Run Locally (optional)

# Create and activate a virtual environment
python3 -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

# Set environment variables
export BUCKET_NAME=your-bucket-name
export AWS_REGION=ap-south-1   # change if needed

# Run the app
python app.py

Now open 👉 http://127.0.0.1:5000/

⚠️ If running locally, make sure AWS credentials are configured (aws configure) or provided via environment variables.
On EC2, use an IAM instance role (no hardcoded keys!).

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⚙️ Environment Variables

Variable	Required	Default	Description
BUCKET_NAME	✅ Yes	—	Your S3 bucket name
AWS_REGION	❌ No	ap-south-1	AWS region
DEFAULT_EXPIRY_SECONDS	❌ No	3600 (1h)	Default link lifetime
MAX_EXPIRY_SECONDS	❌ No	86400 (24h)	Max link lifetime
MAX_CONTENT_LENGTH	❌ No	50MB	Max upload size

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🔐 Security Notes

• Keep the S3 bucket private (Block Public Access = ON)
• Files are only accessible through pre-signed URLs
• For production:
  • Use Gunicorn + Nginx (instead of Flask’s dev server)
  • Enable HTTPS (e.g., via Let’s Encrypt)

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📦 Tech Stack

• Python 3
• Flask
• Boto3
• AWS S3 + EC2