fix(ci): use internal metrics for provider freshness smoke

apps/api/tests/test_alert_chain_smoke_metric.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import importlib.util
+import json
 import sys
 import time
 import unittest
@@ -78,6 +79,50 @@ class AlertChainSmokeMetricTest(unittest.TestCase):
         self.assertFalse(result.passed)
         self.assertTrue(result.critical)
 
+    def test_alert_chain_metric_checks_app_metric_when_prometheus_is_stale(self):
+        fresh_ts = time.time() - 30
+        stale_ts = time.time() - alert_chain_smoke_test.MAX_ALERT_CHAIN_SILENCE_SECONDS - 60
+
+        def fake_get(url, *, params=None, timeout=None):
+            if url.endswith("/api/v1/query"):
+                return alert_chain_smoke_test.HttpGetResult(
+                    200,
+                    json.dumps(
+                        {
+                            "data": {
+                                "result": [
+                                    {
+                                        "metric": {"source": "sentry"},
+                                        "value": [time.time(), str(stale_ts)],
+                                    }
+                                ]
+                            }
+                        }
+                    ),
+                )
+            if url.endswith("/metrics"):
+                return alert_chain_smoke_test.HttpGetResult(
+                    200,
+                    'awoooi_alert_chain_last_success_timestamp{source="sentry"} '
+                    f"{fresh_ts}",
+                )
+            raise AssertionError(f"unexpected url {url}")
+
+        original_get = alert_chain_smoke_test.http_get
+        try:
+            alert_chain_smoke_test.http_get = fake_get
+            result = alert_chain_smoke_test.check_alert_chain_metric(
+                "http://prometheus",
+                "http://api",
+                source="sentry",
+            )
+        finally:
+            alert_chain_smoke_test.http_get = original_get
+
+        self.assertTrue(result.passed)
+        self.assertIn("app_metrics", result.message)
+        self.assertIn("Prometheus scrape 尚未看到", result.message)
+
     def test_source_provider_heartbeat_requires_operator_key(self):
         result = alert_chain_smoke_test.send_source_provider_heartbeat(
             "https://awoooi.example",