Web_Backend

GeoCam Backend Services

This backend consists of two microservices:

1. Node.js Steganography Service (Port 3001) - Handles image steganography encoding/decoding
2. Python Flask API Service (Port 5001) - Handles device registration and verification logic

Architecture

┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   GeoCam App    │    │  Python Flask   │    │  Node.js Steg   │
│  (React Native) │◄──►│   API Service   │◄──►│    Service      │
└─────────────────┘    │   (Port 5001)   │    │   (Port 3001)   │
                       └─────────────────┘    └─────────────────┘
                              │
                    ┌─────────────────┐
                    │   PostgreSQL    │
                    │   Database      │
                    └─────────────────┘

Setup Instructions

Prerequisites

For Docker Deployment (Recommended)

• Docker 20.10+
• Docker Compose 2.0+

For Local Development

• Node.js 18+
• Python 3.11+
• PostgreSQL 15+

Quick Start with Docker

1. Clone and navigate to backend directory:

   cd Web_Backend

2. Configure environment (optional):

   # Copy example environment file
   cp .env.example .env
   
   # Edit .env file with your preferred settings
   # For production, change SECRET_KEY and database passwords

3. Start all services:

   # Build and start all services in detached mode
   docker-compose up --build -d
   
   # Or start with logs visible
   docker-compose up --build

4. Check service health:

   # Check API service
   curl http://localhost:5001/api/health
   
   # Check steganography service
   curl http://localhost:3001/health
   
   # Check all services status
   docker-compose ps

5. Stop services:

   # Stop all services
   docker-compose down
   
   # Stop and remove volumes (WARNING: This will delete database data)
   docker-compose down -v

Local Development Setup

1. Database Setup

# Install PostgreSQL and create database
createdb geocam_db
createuser geocam --password  # Set password as 'geocam'

2. Node.js Steganography Service

# Install dependencies
npm install

# Start service
npm start
# Or for development:
npm run dev

3. Python Flask API Service

# Install dependencies
pip install -r requirements.txt

# Set environment variables
export DATABASE_URL="postgresql://geocam:geocam@localhost:5432/geocam_db"
export STEGANOGRAPHY_SERVICE_URL="http://localhost:3001"

# Start service
python app.py

Database Schema

geocam_devices table:

• id (Primary Key)
• installation_id (Unique)
• device_model
• os_name
• os_version
• public_key_hash
• public_key_data (JSONB)
• registration_date
• geocam_sequence (GeoCam1, GeoCam2, etc.)
• last_activity
• is_active

verification_history table:

• id (Primary Key)
• device_id (Foreign Key)
• verification_timestamp
• image_hash
• verification_result
• verification_message
• signature_data (JSONB)

Configuration

Environment Variables

The following environment variables can be configured:

Database Configuration

• DATABASE_URL - PostgreSQL connection string
  • Docker default: postgresql://geocam:geocam@postgres:5432/geocam_db
  • Local default: postgresql://geocam:geocam@localhost:5432/geocam_db

Service URLs

• STEGANOGRAPHY_SERVICE_URL - Node.js steganography service URL
  • Docker default: http://steganography-service:3001
  • Local default: http://localhost:3001

Flask Configuration

• SECRET_KEY - Flask secret key (⚠️ Change in production!)
• DEBUG - Enable debug mode (true/false)
• PORT - API service port (default: 5001)

Node.js Configuration

• NODE_ENV - Node environment (development/production)

Docker Environment

When using Docker Compose, environment variables are automatically configured in docker-compose.yml. You can override them by:

1. Using .env file (recommended):

   cp .env.example .env
   # Edit .env with your values

2. Direct environment variables:

   export SECRET_KEY="your-secure-key"
   docker-compose up

Local Testing Guide (Hybrid Mode, under the same wifi)

This guide explains how to run steganography service locally while keeping the remote database connection.

Step 1: Configure Local Environment

1. Get Your Local IP Address:

   # On Windows
   ipconfig
   
   # On macOS/Linux
   ifconfig
   # or
   ip addr

   Note down your local IP address (usually starts with 192.168.x.x or 10.0.x.x)

2. Update Mobile App Configuration:

   • Open geoCamApp/utils/backendConfig.ts
   • Set the following variables:

     // Keep main API service in production
     const USE_LOCAL_FOR_TESTING = false;
     // But use local steganography service
     const USE_LOCAL_STEGANOGRAPHY_ONLY = true;
     
     // Update IP address to your local IP (only for steganography service)
     const DEV_STEG_URL = Platform.OS === 'web' 
       ? 'http://localhost:3001' 
       : 'http://YOUR_IP_ADDRESS:3001';

3. Update Backend Configuration:

   • Open Web_Backend/config.py
   • Set the steganography service URL to local:

     STEGANOGRAPHY_SERVICE_URL = os.getenv('STEGANOGRAPHY_SERVICE_URL', 'http://localhost:3001')

Step 2: Start Local Steganography Service

1. Start Node.js Steganography Service:

   # Navigate to Web_Backend
   cd Web_Backend
   
   # Install dependencies if not done
   npm install
   
   # Start steganography service
   node steganography-service.js

2. Start Mobile App (in a new terminal):

   # Navigate to geoCamApp
   cd geoCamApp
   
   # Install dependencies if not done
   npm install
   
   # Start Expo development server
   npx expo start

Step 3: Verify Services

1. Check Local Steganography Service:

   curl http://localhost:3001/health

2. Check Remote API Service:

   curl https://geocam-api.onrender.com/health

Troubleshooting

1. Connection Issues:

   • Ensure steganography service is running on port 3001
   • Check if your phone and computer are on the same network
   • Verify the IP address in backendConfig.ts is correct
   • Try disabling firewall temporarily

2. Port Conflicts:

   • Check if port 3001 is available:

     # On Windows
     netstat -ano | findstr "3001"
     
     # On macOS/Linux
     lsof -i :3001

Switching Back to Production

To switch back to full production environment:

1. Update Mobile App Configuration:

   • In geoCamApp/utils/backendConfig.ts:

     const USE_LOCAL_FOR_TESTING = false;
     const USE_LOCAL_STEGANOGRAPHY_ONLY = false;

2. Update Backend Configuration:

   • In Web_Backend/config.py:

     STEGANOGRAPHY_SERVICE_URL = os.getenv('STEGANOGRAPHY_SERVICE_URL', 'https://geocam-steganography.onrender.com')