[Backport 5.0.x] [Fixes #13966] Harvesters: Integrity error when a title is updated in the remote WMS service

geonode/harvesting/tasks.py

@@ -31,7 +31,7 @@
 from django.db.models.functions import Concat
 from django.utils import timezone
 from django.conf import settings
-from django.db import transaction
+from django.db import transaction, IntegrityError
 
 from geonode.resource.models import ExecutionRequest
 from geonode.resource.enumerator import ExecutionRequestAction
@@ -741,16 +741,30 @@ def _update_harvestable_resources_batch(self, refresh_session_id: int, page: int
         else:
             processed = 0
             for remote_resource in found_resources:
-                resource, created = models.HarvestableResource.objects.get_or_create(
-                    harvester=harvester,
-                    unique_identifier=remote_resource.unique_identifier,
-                    title=remote_resource.title,
-                    defaults={
-                        "should_be_harvested": harvester.harvest_new_resources_by_default,
-                        "remote_resource_type": remote_resource.resource_type,
-                        "last_refreshed": timezone.now(),
-                    },
-                )
+                try:
+                    resource, created = models.HarvestableResource.objects.get_or_create(
+                        harvester=harvester,
+                        unique_identifier=remote_resource.unique_identifier,
+                        defaults={
+                            "title": remote_resource.title,
+                            "should_be_harvested": harvester.harvest_new_resources_by_default,
+                            "remote_resource_type": remote_resource.resource_type,
+                            "last_refreshed": timezone.now(),
+                        },
+                    )
+                except IntegrityError:
+                    # RACE CONDITION: Another worker created this between our SELECT and INSERT.
+                    # We catch the error and simply fetch the one they created.
+                    resource = models.HarvestableResource.objects.get(
+                        harvester=harvester, unique_identifier=remote_resource.unique_identifier
+                    )
+                    created = False
+                # If the resource wasn't just created, check if the title changed
+                # (e.g. from 'copy title' to '28409') and update it.
+                if not created:
+                    resource.title = remote_resource.title
+                    resource.remote_resource_type = remote_resource.resource_type
+
                 processed += 1
                 # NOTE: make sure to save the resource because we need to have its
                 # `last_updated` property be refreshed - this is done in order to be able

geonode/harvesting/tests/test_tasks.py

@@ -251,6 +251,45 @@ def test_update_harvestable_resources_sends_batched_requests(
         # Assert chord was called with expiration
         mock_chord.return_value.apply_async.assert_called_once_with(args=(), expires=123)
 
+    @mock.patch("geonode.harvesting.models.Harvester.get_harvester_worker")
+    def test_update_batch_corrects_title_mismatch(self, mock_get_worker):
+        """
+        Verify that if a remote resource title changes, the existing
+        HarvestableResource is updated instead of causing an IntegrityError.
+        """
+        # Setup the session to be "ON_GOING" so the task doesn't skip it
+        self.harvesting_session.status = models.AsynchronousHarvestingSession.STATUS_ON_GOING
+        self.harvesting_session.save()
+
+        # Pick one of the resources created in setUpTestData
+        # Let's say we target 'fake-identifier-0' which currently has 'fake-title-0'
+        target_uid = "fake-identifier-0"
+        new_remote_title = "COMPLETELY_NEW_TITLE_FROM_WMS"
+
+        # Mock the worker to return the resource with the new title
+        mock_remote_resource = mock.MagicMock()
+        mock_remote_resource.unique_identifier = target_uid
+        mock_remote_resource.title = new_remote_title
+        mock_remote_resource.resource_type = "fake-remote-resource-type"
+
+        mock_worker = mock.MagicMock()
+        mock_worker.list_resources.return_value = [mock_remote_resource]
+        mock_get_worker.return_value = mock_worker
+
+        # Run the batch task using the session ID from setUpTestData
+        # We process page 0 with page_size 1 to just handle our mocked resource
+        tasks._update_harvestable_resources_batch(self.harvesting_session.pk, page=0, page_size=1)
+
+        # ASSERTIONS
+        # Fetch the resource from the DB to see if it updated
+        resource = models.HarvestableResource.objects.get(unique_identifier=target_uid)
+
+        # Verify the title was updated correctly
+        self.assertEqual(resource.title, new_remote_title)
+
+        # Verify no new records were created (count should still be 3 from setUpTestData)
+        self.assertEqual(models.HarvestableResource.objects.count(), 3)
+
     def test_harvesting_scheduler(self):
         mock_harvester = mock.MagicMock(spec=models.Harvester).return_value
         mock_harvester.scheduling_enabled = True