Remove null characters in any string passed to the container / debug task

dispatcher/backend/src/common/utils.py

@@ -16,6 +16,7 @@
 from common.external import advertise_book_to_cms
 from common.notifications import handle_notification
 from errors.http import TaskNotFound, WorkerNotFound
+from utils.check import cleanup_value
 from utils.scheduling import update_schedule_duration
 
 logger = logging.getLogger(__name__)
@@ -87,13 +88,13 @@ def add_to_container_if_present(
         task: dbm.Task, kwargs_key: str, container_key: str
     ) -> None:
         if kwargs_key in kwargs:
-            task.container[container_key] = kwargs[kwargs_key]
+            task.container[container_key] = cleanup_value(kwargs[kwargs_key])
 
     def add_to_debug_if_present(
         task: dbm.Task, kwargs_key: str, debug_key: str
     ) -> None:
         if kwargs_key in kwargs:
-            task.debug[debug_key] = kwargs[kwargs_key]
+            task.debug[debug_key] = cleanup_value(kwargs[kwargs_key])
 
     if "worker" in kwargs:
         task.worker = dbm.Worker.get(session, kwargs["worker"], WorkerNotFound)

dispatcher/backend/src/tests/integration/routes/tasks/test_task.py

@@ -184,3 +184,25 @@ def test_cancel_task(self, client, access_token, tasks):
             }
             response = client.post(url, headers=headers)
             assert response.status_code == 204
+
+
+class TestTaskPatch:
+
+    def test_patch_task(self, client, access_token, tasks):
+        for task in filter(lambda x: x["status"] in [TaskStatus.started], tasks):
+            url = "/tasks/{}".format(task["_id"])
+            headers = {
+                "Authorization": access_token,
+                "Content-Type": "application/json",
+            }
+            response = client.patch(
+                url,
+                headers=headers,
+                json={
+                    "event": "scraper_running",
+                    "payload": {  # control character below must be ignored
+                        "stdout": "some string with ignore bad \u0000character"
+                    },
+                },
+            )
+            assert response.status_code == 204

dispatcher/backend/src/tests/unit/utils/test_check.py

@@ -0,0 +1,15 @@
+import pytest
+
+from utils.check import cleanup_value
+
+
+@pytest.mark.parametrize(
+    "value, expected",
+    [
+        pytest.param("ok", "ok", id="str_simple_ok"),
+        pytest.param("o\u0000k", "ok", id="str_null_character"),
+        pytest.param(123, 123, id="int_simple"),
+    ],
+)
+def test_cleanup_value(value: str, expected: str):
+    assert cleanup_value(value) == expected

dispatcher/backend/src/utils/check.py

@@ -29,3 +29,10 @@ def raise_if(
     """
     if condition:
         raise exception_class(*exception_args)
+
+
+def cleanup_value(value: Any) -> Any:
+    """Remove unwanted characters before inserting / updating in DB"""
+    if isinstance(value, str):
+        return value.replace("\u0000", "")
+    return value