Add source status API and enhance dashboard with data source checks

- Introduced a new API endpoint `/api/source-status/` to return the status of Prometheus and OpenStack data sources.
- Implemented lightweight health check functions for both Prometheus and OpenStack.
- Updated the dashboard template to display the status of data sources dynamically.
- Added tests for the new API endpoint to ensure correct functionality and response handling.
- Configured a cache timeout for source status checks to improve performance.

dashboard/views.py

@@ -5,9 +5,9 @@ from django.conf import settings
 from django.core.cache import cache
 from django.http import JsonResponse
 from django.shortcuts import render
-from dashboard.openstack_utils.connect import get_connection
+from dashboard.openstack_utils.connect import check_openstack, get_connection
 from dashboard.openstack_utils.flavor import get_flavor_list
-from dashboard.prometheus_utils.query import query_prometheus
+from dashboard.prometheus_utils.query import check_prometheus, query_prometheus
 from dashboard.openstack_utils.audits import get_audits, get_current_cluster_cpu
 from dashboard.mock_data import get_mock_context
 
@@ -264,4 +264,24 @@ def api_audits(request):
         connection = get_connection()
         current_cluster = get_current_cluster_cpu(connection)
         cache.set(cache_key_cluster, current_cluster, timeout=cache_ttl)
-    return JsonResponse({"audits": audits, "current_cluster": current_cluster})
+    return JsonResponse({"audits": audits, "current_cluster": current_cluster})
+
+
+def api_source_status(request):
+    """Return status of Prometheus and OpenStack data sources (ok / error / mock)."""
+    if getattr(settings, "USE_MOCK_DATA", False):
+        return JsonResponse({
+            "prometheus": {"status": "mock"},
+            "openstack": {"status": "mock"},
+        })
+
+    cache_key = "dashboard_source_status"
+    cache_ttl = getattr(settings, "SOURCE_STATUS_CACHE_TTL", 30)
+    data = cache.get(cache_key)
+    if data is None:
+        data = {
+            "prometheus": check_prometheus(),
+            "openstack": check_openstack(),
+        }
+        cache.set(cache_key, data, timeout=cache_ttl)
+    return JsonResponse(data)