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18ade12 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 | """
Application startup database verification.
This module provides startup hooks that verify database
connectivity when the application initializes.
"""
import logging
from typing import Optional
from src.db.connection_test import test_connection_with_timeout
from src.models.base import close_db, get_engine, init_db
logger = logging.getLogger(__name__)
class DatabaseStartupError(Exception):
"""Raised when database fails to initialize on startup."""
def __init__(self, message: str = "Database initialization failed"):
self.message = message
super().__init__(self.message)
async def verify_database_connection(
timeout_seconds: float = 5.0,
raise_on_failure: bool = True
) -> bool:
"""
Verify database connection on application startup.
Args:
timeout_seconds: Maximum time to wait for connection
raise_on_failure: If True, raise exception on failure
Returns:
bool: True if connection succeeded
Raises:
DatabaseStartupError: If connection fails and raise_on_failure is True
"""
logger.info("Verifying database connection...")
success, message = await test_connection_with_timeout(timeout_seconds)
if success:
logger.info(f"Database connection verified: {message}")
return True
else:
logger.error(f"Database connection verification failed: {message}")
if raise_on_failure:
raise DatabaseStartupError(message)
return False
async def startup_database(
verify_connection: bool = True,
create_tables: bool = False,
connection_timeout: float = 5.0
) -> None:
"""
Initialize database on application startup.
This function should be called in FastAPI's startup event.
Args:
verify_connection: If True, verify connection before proceeding
create_tables: If True, create all tables (for development)
connection_timeout: Timeout for connection verification
Example:
@app.on_event("startup")
async def on_startup():
await startup_database()
"""
logger.info("Starting database initialization...")
# Verify connection first
if verify_connection:
await verify_database_connection(
timeout_seconds=connection_timeout,
raise_on_failure=True
)
# Optionally create tables (development only)
if create_tables:
logger.info("Creating database tables...")
await init_db()
logger.info("Database tables created")
logger.info("Database initialization complete")
async def shutdown_database() -> None:
"""
Clean up database connections on application shutdown.
This function should be called in FastAPI's shutdown event.
Example:
@app.on_event("shutdown")
async def on_shutdown():
await shutdown_database()
"""
logger.info("Shutting down database connections...")
await close_db()
logger.info("Database connections closed")
# FastAPI lifespan context manager (recommended for newer FastAPI versions)
from contextlib import asynccontextmanager
from typing import AsyncGenerator
@asynccontextmanager
async def database_lifespan(app) -> AsyncGenerator[None, None]:
"""
Database lifespan context manager for FastAPI.
Usage:
app = FastAPI(lifespan=database_lifespan)
"""
# Startup - create_tables=True to auto-create missing tables
await startup_database(verify_connection=True, create_tables=True)
yield
# Shutdown
await shutdown_database()
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