bakery-ia/services/auth/app/main.py

# ================================================================
# services/auth/app/main.py (ENHANCED VERSION)
# ================================================================
"""
Authentication Service Main Application
Enhanced version with proper lifecycle management and microservices integration
"""

import logging
from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from contextlib import asynccontextmanager

from app.core.config import settings
from app.core.database import engine, create_tables
from app.api import auth, users
from app.services.messaging import setup_messaging, cleanup_messaging
from shared.monitoring.logging import setup_logging
from shared.monitoring.metrics import MetricsCollector

# Setup logging
setup_logging("auth-service", settings.LOG_LEVEL)
logger = logging.getLogger(__name__)

# Initialize metrics
metrics = MetricsCollector("auth_service")

@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan events"""
    # Startup
    logger.info("Starting Authentication Service...")
    
    # Create database tables
    await create_tables()
    logger.info("Database tables created")
    
    # Setup messaging
    await setup_messaging()
    logger.info("Messaging setup complete")
    
    # Register metrics
    metrics.register_counter("auth_requests_total", "Total authentication requests")
    metrics.register_counter("auth_login_success_total", "Successful logins")
    metrics.register_counter("auth_login_failure_total", "Failed logins")
    metrics.register_counter("auth_registration_total", "User registrations")
    metrics.register_histogram("auth_request_duration_seconds", "Request duration")
    
    logger.info("Authentication Service started successfully")
    
    yield
    
    # Shutdown
    logger.info("Shutting down Authentication Service...")
    await cleanup_messaging()
    await engine.dispose()
    logger.info("Authentication Service shutdown complete")

# Create FastAPI app
app = FastAPI(
    title="Authentication Service",
    description="Handles user authentication and authorization for bakery forecasting platform",
    version="1.0.0",
    docs_url="/docs",
    redoc_url="/redoc",
    lifespan=lifespan
)

# CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Configure properly for production
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(auth.router, prefix="/api/v1/auth", tags=["authentication"])
app.include_router(users.router, prefix="/api/v1/users", tags=["users"])

# Health check endpoint
@app.get("/health")
async def health_check():
    """Health check endpoint"""
    return {
        "service": "auth-service",
        "status": "healthy",
        "version": "1.0.0"
    }

# Metrics endpoint
@app.get("/metrics")
async def get_metrics():
    """Prometheus metrics endpoint"""
    return metrics.get_metrics()

# Exception handlers
@app.exception_handler(Exception)
async def global_exception_handler(request: Request, exc: Exception):
    """Global exception handler"""
    logger.error(f"Unhandled exception: {exc}", exc_info=True)
    return JSONResponse(
        status_code=500,
        content={"detail": "Internal server error"}
    )

# Request middleware for metrics
@app.middleware("http")
async def metrics_middleware(request: Request, call_next):
    """Middleware to collect metrics"""
    import time
    start_time = time.time()
    
    response = await call_next(request)
    
    # Record metrics
    duration = time.time() - start_time
    metrics.observe_histogram("auth_request_duration_seconds", duration)
    metrics.increment_counter("auth_requests_total")
    
    return response