Cancel scheduled maintenance tasks when all their components are missing

changelog.d/3229.added.md

@@ -0,0 +1 @@
+Active maintenance tasks that only reference deleted components will be automatically cancelled

python/nav/maintengine.py

@@ -86,10 +86,8 @@ def check_tasks_without_end():
 
 @transaction.atomic()
 def do_state_transitions():
-    """
-    Finds active or scheduled tasks that have run out and sets them as passed,
-    and finds scheduled scheduled tasks in the current window and sets them
-    as active.
+    """Finds active or scheduled tasks that have run out and sets them as passed,
+    and finds scheduled tasks in the current window and sets them as active.
     """
     tasks = MaintenanceTask.objects.past().filter(
         state__in=[MaintenanceTask.STATE_ACTIVE, MaintenanceTask.STATE_SCHEDULED]
@@ -105,6 +103,20 @@ def do_state_transitions():
 
     _logger.debug("Tasks transitioned to active state: %r", tasks)
 
+    cancel_tasks_without_components()
+
+
+def cancel_tasks_without_components():
+    """Cancels active tasks where all components are missing"""
+    tasks = MaintenanceTask.objects.filter(
+        state=MaintenanceTask.STATE_ACTIVE
+    ).prefetch_related('maintenance_components')
+    for task in tasks:
+        if not any(task.get_components()):
+            task.state = MaintenanceTask.STATE_CANCELED
+            task.save()
+            _logger.debug("Task %r canceled because all components were missing", task)
+
 
 def check_state_differences():
     """

tests/integration/maintengine_test.py

@@ -0,0 +1,61 @@
+from datetime import datetime, timedelta
+
+import pytest
+
+from nav import maintengine
+from nav.models.msgmaint import MaintenanceTask, MaintenanceComponent
+
+
+class TestCancelTasksWithoutComponents:
+    def test_it_should_cancel_active_empty_tasks(self, empty_task):
+        assert empty_task.state == MaintenanceTask.STATE_ACTIVE
+        maintengine.cancel_tasks_without_components()
+        empty_task.refresh_from_db()
+        assert empty_task.state == MaintenanceTask.STATE_CANCELED
+
+    def test_it_should_not_cancel_scheduled_empty_tasks(self, scheduled_empty_task):
+        assert scheduled_empty_task.state == MaintenanceTask.STATE_SCHEDULED
+        maintengine.cancel_tasks_without_components()
+        scheduled_empty_task.refresh_from_db()
+        assert scheduled_empty_task.state == MaintenanceTask.STATE_SCHEDULED
+
+    def test_it_should_not_cancel_nonempty_tasks(self, half_empty_task):
+        assert half_empty_task.state == MaintenanceTask.STATE_ACTIVE
+        maintengine.cancel_tasks_without_components()
+        half_empty_task.refresh_from_db()
+        assert half_empty_task.state == MaintenanceTask.STATE_ACTIVE
+
+
+@pytest.fixture
+def empty_task(db):
+    task = MaintenanceTask(
+        start_time=datetime.now() - timedelta(minutes=30),
+        end_time=datetime.now() + timedelta(minutes=30),
+        description="Test task",
+        state=MaintenanceTask.STATE_ACTIVE,
+    )
+    task.save()
+    component = MaintenanceComponent(
+        maintenance_task=task,
+        key="netbox",
+        value=99999,
+    )
+    component.save()
+
+    yield task
+
+
+@pytest.fixture
+def scheduled_empty_task(empty_task):
+    empty_task.state = MaintenanceTask.STATE_SCHEDULED
+    empty_task.start_time = datetime.now() + timedelta(minutes=30)
+    empty_task.end_time = datetime.now() + timedelta(minutes=60)
+    empty_task.save()
+    yield empty_task
+
+
+@pytest.fixture
+def half_empty_task(empty_task, localhost):
+    component = MaintenanceComponent(maintenance_task=empty_task, component=localhost)
+    component.save()
+    yield empty_task