Первый коммит

app/modules/shared/db.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+import os
+
+from sqlalchemy import create_engine
+from sqlalchemy.engine import Engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import NullPool
+
+_ENGINE: Engine | None = None
+_SESSION_FACTORY: sessionmaker | None = None
+
+
+def database_url() -> str:
+    return os.getenv("DATABASE_URL", "postgresql+psycopg://agent:agent@db:5432/agent")
+
+
+def get_engine() -> Engine:
+    global _ENGINE
+    if _ENGINE is None:
+        _ENGINE = create_engine(database_url(), poolclass=NullPool, future=True)
+    return _ENGINE
+
+
+def get_session_factory() -> sessionmaker:
+    global _SESSION_FACTORY
+    if _SESSION_FACTORY is None:
+        _SESSION_FACTORY = sessionmaker(bind=get_engine(), autoflush=False, autocommit=False)
+    return _SESSION_FACTORY