Initial commit

core/database.py

@@ -0,0 +1,47 @@
+"""
+Database connection and session management.
+Async SQLAlchemy 2.0 with asyncpg driver.
+"""
+
+import os
+from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
+from sqlalchemy import text
+
+DATABASE_URL = os.getenv(
+    "DATABASE_URL",
+    "postgresql+asyncpg://postgres:postgres@lifeos-db:5432/lifeos_dev"
+)
+
+engine = create_async_engine(
+    DATABASE_URL,
+    echo=os.getenv("ENVIRONMENT") == "development",
+    pool_size=5,
+    max_overflow=10,
+    pool_pre_ping=True,
+)
+
+async_session_factory = async_sessionmaker(
+    engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+)
+
+
+async def get_db():
+    """FastAPI dependency: yields an async database session."""
+    async with async_session_factory() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()
+
+
+async def check_db():
+    """Health check: verify database connectivity."""
+    async with async_session_factory() as session:
+        result = await session.execute(text("SELECT 1"))
+        return result.scalar() == 1