Ensure session is closed (#139)(patch)

Add middleware to ensure the db session is closed before sending the response, so that the connection is released.

Author: seallard

genotype_api/api/app.py

@@ -7,8 +7,9 @@
 from fastapi.responses import JSONResponse
 from fastapi.middleware.cors import CORSMiddleware
 
+from genotype_api.api.middleware import DBSessionMiddleware
 from genotype_api.config import security_settings, settings
-from genotype_api.database.database import create_all_tables, initialise_database, close_session
+from genotype_api.database.database import create_all_tables, initialise_database
 from genotype_api.api.endpoints import samples, snps, users, plates, analyses
 from sqlalchemy.exc import NoResultFound
 
@@ -24,6 +25,7 @@
     allow_methods=["*"],
     allow_headers=["*"],
 )
+app.add_middleware(DBSessionMiddleware)
 
 
 @app.exception_handler(NoResultFound)

genotype_api/api/middleware.py

@@ -0,0 +1,13 @@
+from fastapi import Request
+from starlette.middleware.base import BaseHTTPMiddleware
+from genotype_api.database.database import close_session
+
+
+class DBSessionMiddleware(BaseHTTPMiddleware):
+    def __init__(self, app):
+        super().__init__(app)
+
+    async def dispatch(self, request: Request, call_next):
+        response = await call_next(request)
+        close_session()
+        return response