db.session.remove() in celery post run hook

backend/geonature/celery_app.py

@@ -14,6 +14,7 @@
 
 app.Task = ContextTask
 
+app.conf.imports += ("geonature.tasks",)
 app.conf.imports += tuple(
     [ep.module for dist in iter_modules_dist() for ep in dist.entry_points.select(name="tasks")]
 )

backend/geonature/tasks/__init__.py

@@ -0,0 +1,9 @@
+from celery.signals import task_postrun
+
+from geonature.utils.env import db
+from geonature.utils.celery import celery_app
+
+
+@task_postrun.connect
+def close_session(*args, **kwargs):
+    db.session.remove()