price-tracker/DOCKER.md

Price Tracker - Docker Deployment

This guide covers how to build, deploy, and run the Price Tracker application using Docker.

Quick Start with Docker

1. Build the Image

# Build with default tag
./build.sh

# Build with specific tag
./build.sh v1.0.0

# Build and tag for your registry
./build.sh latest your-registry.com

2. Configure Environment Variables (Optional)

# Copy the example environment file
cp .env.example .env

# Edit the .env file with your settings
nano .env

3. Run with Docker Compose (Recommended)

# Start the application
docker-compose up -d

# View logs
docker-compose logs -f

# Stop the application
docker-compose down

4. Manual Docker Run

# Create directories for persistence
mkdir -p data logs

# Run with environment variables
docker run -d \
  --name price-tracker \
  --restart unless-stopped \
  -p 5000:5000 \
  -v $(pwd)/data:/app/data \
  -v $(pwd)/logs:/app/logs \
  -v $(pwd)/config.json:/app/config.json:ro \
  -e FLASK_ENV=production \
  -e DATABASE_PATH=/app/data/price_tracker.db \
  -e EMAIL_ENABLED=true \
  -e SMTP_SERVER=smtp.gmail.com \
  -e SENDER_EMAIL=your-email@gmail.com \
  -e SENDER_PASSWORD=your-app-password \
  -e RECIPIENT_EMAIL=alerts@yourdomain.com \
  price-tracker:latest

Environment Variable Configuration

The application supports environment variable overrides for flexible deployment configurations. This allows you to customize settings without modifying the config.json file.

Available Environment Variables

Database Configuration

• DATABASE_PATH - Path to SQLite database file (default: /app/data/price_tracker.db)

Scraping Configuration

• DELAY_BETWEEN_REQUESTS - Delay between requests in seconds (default: 2)
• MAX_CONCURRENT_REQUESTS - Maximum concurrent requests (default: 1)
• REQUEST_TIMEOUT - Request timeout in seconds (default: 30)
• RETRY_ATTEMPTS - Number of retry attempts (default: 3)

Email Notifications

• EMAIL_ENABLED - Enable email notifications (true/false)
• SMTP_SERVER - SMTP server hostname (e.g., smtp.gmail.com)
• SMTP_PORT - SMTP server port (e.g., 587)
• SENDER_EMAIL - Email address to send from
• SENDER_PASSWORD - Email password or app password
• RECIPIENT_EMAIL - Email address to send alerts to

Webhook Notifications

• WEBHOOK_ENABLED - Enable webhook notifications (true/false)
• WEBHOOK_URL - Webhook URL for sending alerts

Configuration Priority

Environment variables take precedence over config.json settings:

1. Environment Variables (highest priority)
2. config.json file (fallback)

Using .env Files

Create a .env file from the example:

cp .env.example .env

Edit the .env file with your settings:

# Database
DATABASE_PATH=/app/data/price_tracker.db

# Email notifications
EMAIL_ENABLED=true
SMTP_SERVER=smtp.gmail.com
SMTP_PORT=587
SENDER_EMAIL=alerts@mydomain.com
SENDER_PASSWORD=my-app-password
RECIPIENT_EMAIL=me@mydomain.com

# Scraping
DELAY_BETWEEN_REQUESTS=3
MAX_CONCURRENT_REQUESTS=2

Docker Compose will automatically load the .env file:

docker-compose up -d

Registry Deployment

Push to Registry

# Tag for your registry
docker tag price-tracker:latest your-registry.com/price-tracker:latest

# Push to registry
docker push your-registry.com/price-tracker:latest

Deploy from Registry

# Deploy using script
./deploy.sh latest your-registry.com

# Or manually
docker pull your-registry.com/price-tracker:latest
docker run -d \
  --name price-tracker \
  --restart unless-stopped \
  -p 5000:5000 \
  -v $(pwd)/data:/app/data \
  -v $(pwd)/logs:/app/logs \
  -v $(pwd)/config.json:/app/config.json:ro \
  -e FLASK_ENV=production \
  your-registry.com/price-tracker:latest

Environment Variables

Variable	Default	Description
FLASK_HOST	0.0.0.0	Host to bind the Flask server
FLASK_PORT	5000	Port to bind the Flask server
FLASK_ENV	production	Flask environment (production/development)
PYTHONUNBUFFERED	1	Enable unbuffered Python output

Volumes

Container Path	Description
/app/data	Database and persistent data
/app/logs	Application logs
/app/config.json	Configuration file (read-only)

Health Check

The container includes a health check that verifies the application is responding on port 5000.

# Check container health
docker ps

# View health check logs
docker inspect price-tracker | grep -A 10 Health

Monitoring

View Logs

# Real-time logs
docker logs -f price-tracker

# Last 100 lines
docker logs --tail 100 price-tracker

# With docker-compose
docker-compose logs -f

Container Stats

# Resource usage
docker stats price-tracker

# Container information
docker inspect price-tracker

Troubleshooting

Container Won't Start

1. Check logs: docker logs price-tracker
2. Verify config file exists and is valid JSON
3. Ensure data and logs directories exist with correct permissions

Application Not Accessible

1. Verify port mapping: docker ps
2. Check firewall settings
3. Verify container is healthy: docker ps (should show "healthy")

Database Issues

1. Check if data directory is properly mounted
2. Verify database file permissions
3. Check logs for database errors

Production Considerations

Security

• Run container as non-root user (already configured)
• Use read-only config file mount
• Consider running behind a reverse proxy (nginx, traefik)
• Set up proper firewall rules

Performance

• Allocate sufficient memory for scraping operations
• Consider scaling with multiple instances behind a load balancer
• Monitor resource usage and adjust limits as needed

Backup

# Backup data directory
tar -czf price-tracker-backup-$(date +%Y%m%d).tar.gz data/

# Restore backup
tar -xzf price-tracker-backup-YYYYMMDD.tar.gz

Development

Local Development with Docker

# Build development image
docker build -t price-tracker:dev .

# Run with development settings
docker run -it --rm \
  -p 5000:5000 \
  -v $(pwd):/app \
  -e FLASK_ENV=development \
  price-tracker:dev

Debugging

# Run container with bash shell
docker run -it --rm \
  -v $(pwd):/app \
  price-tracker:latest \
  /bin/bash

# Execute commands in running container
docker exec -it price-tracker /bin/bash