From 8e4271dbf70ae530d2d7f69a937b47e38907a50d Mon Sep 17 00:00:00 2001
From: Emmanuel Evbuomwan <emmanuel.evbuomwan@aiven.io>
Date: Mon, 26 Aug 2024 15:41:18 +0200
Subject: [PATCH] rapu: fire shutdown metric on app shutdown

- we add the `karapace_shutdown_count` metric, to
the base app and fire the metric on app shutdown
- the `close_by_app()` is added to the app shutdown hooks and thus is
called on app shutdown
---
 karapace/rapu.py        |  3 +++
 tests/unit/test_rapu.py | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/karapace/rapu.py b/karapace/rapu.py
index bfccebfe9..c4e4c5ee3 100644
--- a/karapace/rapu.py
+++ b/karapace/rapu.py
@@ -164,6 +164,7 @@ def __init__(
         self.app_name = app_name
         self.config = config
         self.app_request_metric = f"{app_name}_request"
+        self.app_shutdown_count_metric = f"{app_name}_shutdown_count"
         self.app = self._create_aiohttp_application(config=config)
         self.log = logging.getLogger(self.app_name)
         self.stats = StatsClient(config=config)
@@ -183,6 +184,8 @@ async def close(self) -> None:
         set as hook because the awaitables have to run inside the event loop
         created by the aiohttp library.
         """
+        self.log.warning("=======> Received shutdown signal, closing Application <=======")
+        self.stats.increase(self.app_shutdown_count_metric)
         self.stats.close()
 
     @staticmethod
diff --git a/tests/unit/test_rapu.py b/tests/unit/test_rapu.py
index 304af2603..cde68e2be 100644
--- a/tests/unit/test_rapu.py
+++ b/tests/unit/test_rapu.py
@@ -2,13 +2,16 @@
 Copyright (c) 2023 Aiven Ltd
 See LICENSE for details
 """
+from _pytest.logging import LogCaptureFixture
 from aiohttp.client_exceptions import ClientConnectionError
 from aiohttp.web import Request
 from karapace.config import DEFAULTS
 from karapace.karapace import KarapaceBase
 from karapace.rapu import HTTPRequest, REST_ACCEPT_RE, REST_CONTENT_TYPE_RE
+from karapace.statsd import StatsClient
 from unittest.mock import Mock
 
+import logging
 import pytest
 
 
@@ -180,3 +183,18 @@ async def test_raise_connection_error_handling(connection_error: BaseException)
     assert response.status == 503
     request_mock.read.assert_has_calls([])
     callback_mock.assert_not_called()
+
+
+async def test_close_by_app(caplog: LogCaptureFixture) -> None:
+    app = KarapaceBase(config=DEFAULTS)
+    app.stats = Mock(spec=StatsClient)
+
+    with caplog.at_level(logging.WARNING, logger="karapace.rapu"):
+        await app.close_by_app(app=app.app)
+
+    app.stats.increase.assert_called_once_with("karapace_shutdown_count")
+    app.stats.close.assert_called_once()
+    for log in caplog.records:
+        assert log.name == "karapace"
+        assert log.levelname == "WARNING"
+        assert log.message == "=======> Received shutdown signal, closing Application <======="