metrics: Add the first (simple) custom metrics

core/core/management/commands/update_metrics.py

@@ -0,0 +1,8 @@
+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

@@ -0,0 +1,11 @@
+from prometheus_client import Gauge
+from django_prometheus import exports
+from inventory.models import *
+
+g_items_total = Gauge('c3lf_items_total', 'Current Total items')
+
+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)

core/core/settings.py

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

core/core/urls.py

@@ -19,6 +19,8 @@ from django.urls import path, include
 
 from .version import get_info
 
+from .metrics import *
+
 urlpatterns = [
     path('djangoadmin/', admin.site.urls),
     path('api/2/', include('inventory.api_v2')),