Allow plugins to register system jobs

docs/plugins/development/background-jobs.md

@@ -31,12 +31,20 @@ You can schedule the background job from within your code (e.g. from a model's `
 
 ### Attributes
 
-`JobRunner` attributes are defined under a class named `Meta` within the job. These are optional, but encouraged.
+`JobRunner` attributes are defined under a class named `Meta` within the job. These are optional (unless specified otherwise), but encouraged.
 
 #### `name`
 
 This is the human-friendly names of your background job. If omitted, the class name will be used.
 
+#### `enabled`
+
+When the `JobRunner` is defined as [system job](#system-jobs), this attribute controls whether a job will be scheduled. By default, this attribute is `True`.
+
+#### `interval` *(required for system jobs)*
+
+When the `JobRunner` is defined as [system job](#system-jobs), this attribute controls the interval of the scheduled job.
+
 ### Scheduled Jobs
 
 As described above, jobs can be scheduled for immediate execution or at any later time using the `enqueue()` method. However, for management purposes, the `enqueue_once()` method allows a job to be scheduled exactly once avoiding duplicates. If a job is already scheduled for a particular instance, a second one won't be scheduled, respecting thread safety. An example use case would be to schedule a periodic task that is bound to an instance in general, but not to any event of that instance (such as updates). The parameters of the `enqueue_once()` method are identical to those of `enqueue()`.
@@ -62,6 +70,33 @@ class MyModel(NetBoxModel):
         MyTestJob.enqueue(instance=self)
 ```
 
+
+### System Jobs
+
+Some plugins may implement background jobs that are decoupled from any object and the request-response cycle. Typical use cases would be housekeeping tasks or synchronization jobs. These can be created using *system jobs*. The `JobRunner` class has everything included to provide this type of job as well. Just add the appropriate metadata to let NetBox schedule all background jobs automatically.
+
+!!! info
+    All system jobs are automatically scheduled just before the `./manage.py rqworker` command is started and the job queue is processed. The schedules are also checked at each restart of this process.
+
+#### Example
+
+```python title="jobs.py"
+from netbox.jobs import JobRunner
+from .models import MyModel
+
+class MyHousekeepingJob(JobRunner):
+    class Meta:
+        name = "My Housekeeping Job"
+        interval = 60  # every 60 minutes
+
+    def run(self, *args, **kwargs):
+        MyModel.objects.filter(foo='bar').delete()
+
+system_jobs = (
+    MyHousekeepingJob,
+)
+```
+
 ## Task queues
 
 Three task queues of differing priority are defined by default:

docs/plugins/development/data-backends.md

@@ -18,6 +18,6 @@ backends = [MyDataBackend]
 ```
 
 !!! tip
-    The path to the list of search indexes can be modified by setting `data_backends` in the PluginConfig instance.
+    The path to the list of data backends can be modified by setting `data_backends` in the PluginConfig instance.
 
 ::: netbox.data_backends.DataBackend

netbox/netbox/plugins/__init__.py

@@ -8,7 +8,7 @@ from packaging import version
 
 from netbox.registry import registry
 from netbox.search import register_search
-from netbox.utils import register_data_backend
+from netbox.utils import register_data_backend, register_system_job
 from .navigation import *
 from .registration import *
 from .templates import *
@@ -26,6 +26,7 @@ registry['plugins'].update({
 DEFAULT_RESOURCE_PATHS = {
     'search_indexes': 'search.indexes',
     'data_backends': 'data_backends.backends',
+    'system_jobs': 'jobs.system_jobs',
     'graphql_schema': 'graphql.schema',
     'menu': 'navigation.menu',
     'menu_items': 'navigation.menu_items',
@@ -73,6 +74,7 @@ class PluginConfig(AppConfig):
     # Optional plugin resources
     search_indexes = None
     data_backends = None
+    system_jobs = None
     graphql_schema = None
     menu = None
     menu_items = None
@@ -111,6 +113,11 @@ class PluginConfig(AppConfig):
         for backend in data_backends:
             register_data_backend()(backend)
 
+        # Register system jobs (if defined)
+        system_jobs = self._load_resource('system_jobs') or []
+        for job in system_jobs:
+            register_system_job()(job)
+
         # Register template content (if defined)
         if template_extensions := self._load_resource('template_extensions'):
             register_template_extensions(template_extensions)

netbox/netbox/tests/dummy_plugin/jobs.py

@@ -0,0 +1,14 @@
+from netbox.jobs import JobRunner
+
+
+class DummySystemJob(JobRunner):
+    class Meta:
+        interval = 60
+
+    def run(self, *args, **kwargs):
+        pass
+
+
+system_jobs = (
+    DummySystemJob,
+)

netbox/netbox/tests/test_plugins.py

@@ -7,6 +7,7 @@ from django.urls import reverse
 
 from netbox.tests.dummy_plugin import config as dummy_config
 from netbox.tests.dummy_plugin.data_backends import DummyBackend
+from netbox.tests.dummy_plugin.jobs import DummySystemJob
 from netbox.plugins.navigation import PluginMenu
 from netbox.plugins.utils import get_plugin_config
 from netbox.graphql.schema import Query
@@ -130,6 +131,13 @@ class PluginTest(TestCase):
         self.assertIn('dummy', registry['data_backends'])
         self.assertIs(registry['data_backends']['dummy'], DummyBackend)
 
+    def test_system_jobs(self):
+        """
+        Check registered system jobs.
+        """
+        self.assertIn(DummySystemJob.name, registry['system_jobs'])
+        self.assertIs(registry['system_jobs'][DummySystemJob.name], DummySystemJob)
+
     def test_queues(self):
         """
         Check that plugin queues are registered with the accurate name.