From 89bfc325caa86fd0af4eaa691d04e6772d55f588 Mon Sep 17 00:00:00 2001
From: asmita singh <asmita.singh@nttdata.com>
Date: Wed, 27 Feb 2019 13:40:32 +0000
Subject: [PATCH] Handle SIGHUP signal for blazar-manager correctly

After a SIGHUP signal is sent to blazar-manager, the RPC messaging
between API and blazar-manager stops working and users start seeing
"Internal Server Error".

This issue is fixed in this patch, which adds a wait method to the
RPCServer class and calls the wait method of the RPC server from
oslo.messaging, so that all existing requests are fulfilled before
restarting the blazar-manager service again.

Change-Id: I8272975afeabfb74f974e9bf9a6ae9162c22a6e0
Closes-Bug: #1807689
---
 blazar/tests/manager/test_service.py | 13 +++++++++++++
 blazar/utils/service.py              |  4 ++++
 2 files changed, 17 insertions(+)

diff --git a/blazar/tests/manager/test_service.py b/blazar/tests/manager/test_service.py
index 1d1dc23c..d12197ae 100644
--- a/blazar/tests/manager/test_service.py
+++ b/blazar/tests/manager/test_service.py
@@ -19,6 +19,7 @@ import ddt
 import eventlet
 import mock
 from oslo_config import cfg
+import oslo_messaging as messaging
 from six.moves import reload_module
 from stevedore import enabled
 import testtools
@@ -1561,3 +1562,15 @@ class ServiceTestCase(tests.TestCase):
         self.manager.plugins = {'physical:host': None}
         self.assertRaises(AttributeError, getattr, self.manager,
                           'physical:host:method_not_present')
+
+    @mock.patch.object(messaging, 'get_rpc_server')
+    def test_rpc_server(self, mock_get_rpc_server):
+        server = service.ManagerService()
+        server.start()
+        for m in server.monitors:
+            m.start_monitoring.assert_called_once()
+        server.stop()
+        server._server.stop.assert_called_once()
+        server.wait()
+        server._server.wait.assert_called_once()
+        self.assertEqual(1, mock_get_rpc_server.call_count)
diff --git a/blazar/utils/service.py b/blazar/utils/service.py
index af36ea05..745c120a 100644
--- a/blazar/utils/service.py
+++ b/blazar/utils/service.py
@@ -58,6 +58,10 @@ class RPCServer(service.Service):
         super(RPCServer, self).start()
         self.tg.add_thread(self._server.start)
 
+    def wait(self):
+        super(RPCServer, self).wait()
+        self._server.wait()
+
     def stop(self):
         super(RPCServer, self).stop()
         self._server.stop()