metrics: Make metrics actually usable

core/core/management/commands/update_metrics.py

@@ -1,8 +0,0 @@
-from django.core.management.base import BaseCommand, CommandError
-from core.metrics import update_item_count
-
-class Command(BaseCommand):
-    help = "Refresh the metrics"
-    
-    def handle(self, *args, **options):
-        update_item_count()

core/core/metrics.py

@@ -1,11 +1,16 @@
-from prometheus_client import Gauge
-from django_prometheus import exports
-from inventory.models import *
+from django.apps import apps
+from prometheus_client.core import CounterMetricFamily, REGISTRY
 
-g_items_total = Gauge('c3lf_items_total', 'Current Total items')
+class ModelCountCollector(object):
 
-def update_item_count():
-    # Get the count of MyModel objects
-    count = Item.objects.count()
-    # Set the gauge to the current count
-    g_items_total.set(count)
+    def collect(self):
+        counter = CounterMetricFamily('model_count', 'Number of objects per model', labels=['model', 'app'])
+        yield counter
+        if not apps.models_ready or not apps.apps_ready:
+            return
+        for app_name, app_config in apps.app_configs.items():
+            for model in app_config.get_models():
+                counter.add_metric([model.__name__, app_name], model.objects.count())
+        yield counter
+
+REGISTRY.register(ModelCountCollector())

core/core/settings.py

@@ -70,7 +70,6 @@ INSTALLED_APPS = [
     'inventory',
     'mail',
     'notify_sessions',
-    'core'
 ]
 
 REST_FRAMEWORK = {