Use the new scoped_session SessionManager

common/database_helpers.py

@@ -2,36 +2,18 @@
 import logging
 from abc import ABC, abstractmethod
 
-from sqlalchemy import create_engine, asc, desc
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy import asc, desc
 
-from common.constants import Constants
 from common.exceptions import MissingRecordError, BadFilterError, BadRequestError
+from common.session_manager import session_manager
 
 log = logging.getLogger()
 
 
-class SessionManager(object):
-    _session = None
-
-    @staticmethod
-    def get_icat_db_session():
-        """
-        Checks if a session exists, if it does it returns the session if not a new one is created
-        :return: ICAT DB session
-        """
-        log.info(" Getting ICAT DB session")
-        if SessionManager._session is None:
-            engine = create_engine(Constants.DATABASE_URL)
-            Session = sessionmaker(bind=engine)
-            SessionManager._session = Session()
-        return SessionManager._session
-
-
 class Query(ABC):
     @abstractmethod
     def __init__(self, table):
-        self.session = SessionManager.get_icat_db_session()
+        self.session = session_manager.get_icat_db_session()
         self.table = table
         self.base_query = self.session.query(table)
         self.is_limited = False

common/helpers.py

@@ -6,30 +6,32 @@
 from flask_restful import reqparse
 from sqlalchemy.exc import IntegrityError
 
-from common.database_helpers import SessionManager
 from common.exceptions import MissingRecordError, BadFilterError, AuthenticationError, BadRequestError
 from common.models.db_models import SESSION
-
+from common.session_manager import session_manager
 
 log = logging.getLogger()
 
+
 def requires_session_id(method):
     """
     Decorator for endpoint resources that makes sure a valid session_id is provided in requests to that endpoint
     :param method: The method for the endpoint
     :returns a 403, "Forbidden" if a valid session_id is not provided with the request
     """
     log.info("")
+
     @wraps(method)
     def wrapper_requires_session(*args, **kwargs):
         log.info(" Authenticating consumer")
         try:
-            session = SessionManager.get_icat_db_session()
+            session = session_manager.get_icat_db_session()
             query = session.query(SESSION).filter(
                 SESSION.ID == get_session_id_from_auth_header()).first()
             if query is not None:
                 log.info(" Closing DB session")
                 session.close()
+                session.close()
                 log.info(" Consumer authenticated")
                 return method(*args, **kwargs)
             else:
@@ -38,6 +40,7 @@ def wrapper_requires_session(*args, **kwargs):
                 return "Forbidden", 403
         except AuthenticationError:
             return "Forbidden", 403
+
     return wrapper_requires_session