Allow system jobs to be registered

A new registry key allows background system jobs to be registered and
automatically scheduled when rqworker starts.

netbox/core/management/commands/rqworker.py

@@ -1,7 +1,10 @@
 import logging
 
+from django.core.management.base import CommandError
 from django_rq.management.commands.rqworker import Command as _Command
 
+from netbox.registry import registry
+
 
 DEFAULT_QUEUES = ('high', 'default', 'low')
 
@@ -14,6 +17,16 @@ class Command(_Command):
     of only the 'default' queue).
     """
     def handle(self, *args, **options):
+        # Setup system jobs.
+        for job in registry['system_jobs'].values():
+            if getattr(job.Meta, 'enabled', True):
+                try:
+                    logger.debug(f"Scheduling system job {job.name}")
+                    job.enqueue_once(interval=getattr(job.Meta, 'interval'))
+
+                except AttributeError as e:
+                    raise CommandError(f"Job {job.name} is missing required attribute in Meta: {e.name}")
+
         # Run the worker with scheduler functionality
         options['with_scheduler'] = True
 

netbox/netbox/registry.py

@@ -30,6 +30,7 @@ registry = Registry({
     'models': collections.defaultdict(set),
     'plugins': dict(),
     'search': dict(),
+    'system_jobs': dict(),
     'tables': collections.defaultdict(dict),
     'views': collections.defaultdict(dict),
     'widgets': dict(),

netbox/netbox/utils.py

@@ -3,6 +3,7 @@ from netbox.registry import registry
 __all__ = (
     'get_data_backend_choices',
     'register_data_backend',
+    'register_system_job',
 )
 
 
@@ -24,3 +25,14 @@ def register_data_backend():
         return cls
 
     return _wrapper
+
+
+def register_system_job():
+    """
+    Decorator for registering a `JobRunner` class as system background job.
+    """
+    def _wrapper(cls):
+        registry['system_jobs'][cls.name] = cls
+        return cls
+
+    return _wrapper