provide interface for database to get transaction manager

src/plone.server/plone/server/commands/migrate.py

@@ -118,10 +118,11 @@ def run(self, arguments, settings, app):
                         app, to_version=arguments.to_version,
                         from_version=installed_versions.get(app))
                     if len(_migrations) > 0:
+                        trns = db.get_transaction_manager()
                         if not arguments.dry_run and not arguments.report:
-                            db.tm_.begin()
+                            trns.begin()
                         migrate.run_site_migrations(site, _migrations, db)
                         if not arguments.dry_run and not arguments.report:
-                            db.tm_.commit()
+                            trns.commit()
 
         self.report(arguments, sites, apps)

src/plone.server/plone/server/factory.py

@@ -190,6 +190,9 @@ def __init__(self, id, db):
         self._conn = None
         self.tm_ = RequestAwareTransactionManager()
 
+    def get_transaction_manager(self):
+        return self.tm_
+
     def open(self):
         tm_ = RequestAwareTransactionManager()
         return self._db.open(transaction_manager=tm_)
@@ -221,7 +224,7 @@ def keys(self):
         return list(self.conn.root().keys())
 
     def __setitem__(self, key, value):
-        """ This operation can only be done throw HTTP request
+        """ This operation can only be done through HTTP request
 
         We can check if there is permission to delete a site
         XXX TODO

src/plone.server/plone/server/interfaces/content.py

@@ -32,7 +32,11 @@ class IApplication(Interface):
 
 
 class IDatabase(Interface):
-    pass
+    def get_transaction_manager():
+        pass
+
+    def open():
+        pass
 
 
 class IStaticFile(Interface):