# Build Docker image
docker build -t myapp .

# Run with Docker Compose
docker-compose up -d

# Deploy to cloud
gunicorn --bind 0.0.0.0:8000 app:app

# config.py
import os
from urllib.parse import quote_plus

class ProductionConfig:
    """Production configuration."""
    
    # Security
    SECRET_KEY = os.environ.get('SECRET_KEY')
    DEBUG = False
    TESTING = False
    
    # Database
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or \
        f"postgresql://{os.environ.get('DB_USER')}:{quote_plus(os.environ.get('DB_PASSWORD'))}@" \
        f"{os.environ.get('DB_HOST')}:{os.environ.get('DB_PORT', '5432')}/{os.environ.get('DB_NAME')}"
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_ENGINE_OPTIONS = {
        'pool_size': 10,
        'max_overflow': 20,
        'pool_recycle': 3600,
        'pool_pre_ping': True
    }
    
    # Security Headers
    SECURITY_HEADERS = {
        'Strict-Transport-Security': 'max-age=31536000; includeSubDomains',
        'X-Content-Type-Options': 'nosniff',
        'X-Frame-Options': 'DENY',
        'X-XSS-Protection': '1; mode=block',
        'Content-Security-Policy': "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'"
    }
    
    # Session
    SESSION_COOKIE_SECURE = True
    SESSION_COOKIE_HTTPONLY = True
    SESSION_COOKIE_SAMESITE = 'Lax'
    PERMANENT_SESSION_LIFETIME = 3600  # 1 hour
    
    # Cache
    CACHE_TYPE = 'redis'
    CACHE_REDIS_URL = os.environ.get('REDIS_URL', 'redis://localhost:6379/0')
    CACHE_DEFAULT_TIMEOUT = 300
    
    # Rate Limiting
    RATELIMIT_STORAGE_URL = os.environ.get('REDIS_URL', 'redis://localhost:6379/1')
    RATELIMIT_DEFAULT = '100/hour'
    
    # Logging
    LOG_LEVEL = os.environ.get('LOG_LEVEL', 'INFO')
    LOG_FILE = os.environ.get('LOG_FILE', '/var/log/app/app.log')
    
    # File Upload
    MAX_CONTENT_LENGTH = 16 * 1024 * 1024  # 16MB
    UPLOAD_FOLDER = os.environ.get('UPLOAD_FOLDER', '/var/uploads')
    
    # Email
    MAIL_SERVER = os.environ.get('MAIL_SERVER')
    MAIL_PORT = int(os.environ.get('MAIL_PORT', 587))
    MAIL_USE_TLS = os.environ.get('MAIL_USE_TLS', 'true').lower() in ['true', 'on', '1']
    MAIL_USERNAME = os.environ.get('MAIL_USERNAME')
    MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD')
    MAIL_DEFAULT_SENDER = os.environ.get('MAIL_DEFAULT_SENDER')

# wsgi.py
import os
from app import create_app

# Get environment
config_name = os.environ.get('FLASK_ENV', 'production')
app = create_app(config_name)

if __name__ == "__main__":
    app.run()

# gunicorn.conf.py
import multiprocessing
import os

# Server socket
bind = f"0.0.0.0:{os.environ.get('PORT', 8000)}"
backlog = 2048

# Worker processes
workers = multiprocessing.cpu_count() * 2 + 1
worker_class = 'sync'
worker_connections = 1000
timeout = 30
keepalive = 60
max_requests = 1000
max_requests_jitter = 100

# Security
limit_request_line = 4094
limit_request_fields = 100
limit_request_field_size = 8190

# Logging
accesslog = '-'
errorlog = '-'
loglevel = os.environ.get('LOG_LEVEL', 'info').lower()
access_log_format = '%(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s "%(f)s" "%(a)s" %(D)s'

# Process naming
proc_name = 'flask_app'

# Server mechanics
daemon = False
pidfile = '/tmp/gunicorn.pid'
user = os.environ.get('USER', 'www-data')
group = os.environ.get('GROUP', 'www-data')
tmp_upload_dir = None

# SSL
keyfile = os.environ.get('SSL_KEYFILE')
certfile = os.environ.get('SSL_CERTFILE')

# Dockerfile
FROM python:3.11-slim

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    PIP_NO_CACHE_DIR=1 \
    PIP_DISABLE_PIP_VERSION_CHECK=1

# Install system dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    libpq-dev \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Create app user
RUN groupadd -r appuser && useradd -r -g appuser appuser

# Set work directory
WORKDIR /app

# Install Python dependencies
COPY requirements/production.txt ./requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Create necessary directories
RUN mkdir -p /var/log/app /var/uploads && \
    chown -R appuser:appuser /app /var/log/app /var/uploads

# Switch to non-root user
USER appuser

# Expose port
EXPOSE 8000

# Health check
HEALTHCHECK --interval=30s --timeout=30s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:8000/health || exit 1

# Run application
CMD ["gunicorn", "--config", "gunicorn.conf.py", "wsgi:app"]

# docker-compose.yml
version: '3.8'

services:
  web:
    build: .
    ports:
      - "8000:8000"
    environment:
      - FLASK_ENV=production
      - DATABASE_URL=postgresql:/