From 818ca43e78ea7d8a908cefa41970bd26f4ddea26 Mon Sep 17 00:00:00 2001
From: Maurice Escher <maurice.escher@sap.com>
Date: Wed, 21 Apr 2021 10:11:03 +0200
Subject: [PATCH] init_host should be called before RPC consumer is created

This change adds a new hook to Manager class called init_host_with_rpc()
to allow services like scheduler to do something once RPC is ready.

Copied from cinder https://opendev.org/openstack/cinder/commit/65fa80c361f71158cc492dfc520dc4a63ccfa419
and https://opendev.org/openstack/cinder/commit/60c563f72d2d6d008fca03f0a058941f3807e1a8

Change-Id: Iac6507a6e395c55f0fec453650009f08c2bb6563
Closes-Bug: #1271568
(cherry picked from commit 0339802a5d0801cda19c464a87853b60982ae011)
(cherry picked from commit 887c4bf4c041cfaafaf1c47edb9262574bbb959a)
(cherry picked from commit d3481f5c2645fa96c710b4298c44ba915f7d9d92)
(cherry picked from commit ad9042b2551d944aa9bf17488117419daf42e9c2)
---
 manila/manager.py                                  | 14 +++++++++++++-
 manila/scheduler/manager.py                        |  2 +-
 manila/service.py                                  |  4 +++-
 manila/tests/scheduler/test_manager.py             |  4 ++--
 ...ix-rpc-init-host-with-rpc-6e76afa553b4f2af.yaml |  6 ++++++
 5 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 releasenotes/notes/bug-1271568-fix-rpc-init-host-with-rpc-6e76afa553b4f2af.yaml

diff --git a/manila/manager.py b/manila/manager.py
index 210c9d706c..296b9f0c98 100644
--- a/manila/manager.py
+++ b/manila/manager.py
@@ -101,7 +101,19 @@ class Manager(base.Base, PeriodicTasks):
     def init_host(self):
         """Handle initialization if this is a standalone service.
 
-        Child classes should override this method.
+        A hook point for services to execute tasks before the services are made
+        available (i.e. showing up on RPC and starting to accept RPC calls) to
+        other components.  Child classes should override this method.
+
+        """
+        pass
+
+    def init_host_with_rpc(self):
+        """A hook for service to do jobs after RPC is ready.
+
+        Like init_host(), this method is a hook where services get a chance
+        to execute tasks that *need* RPC. Child classes should override
+        this method.
 
         """
         pass
diff --git a/manila/scheduler/manager.py b/manila/scheduler/manager.py
index 3a5957e5a2..d60ba00aa2 100644
--- a/manila/scheduler/manager.py
+++ b/manila/scheduler/manager.py
@@ -83,7 +83,7 @@ class SchedulerManager(manager.Manager):
         self.message_api = message_api.API()
         super(SchedulerManager, self).__init__(*args, **kwargs)
 
-    def init_host(self):
+    def init_host_with_rpc(self):
         ctxt = context.get_admin_context()
         self.request_service_capabilities(ctxt)
 
diff --git a/manila/service.py b/manila/service.py
index 32345cc562..bce1effd4c 100644
--- a/manila/service.py
+++ b/manila/service.py
@@ -105,6 +105,7 @@ class Service(service.Service):
         LOG.info('Starting %(topic)s node (version %(version_string)s)',
                  {'topic': self.topic, 'version_string': version_string})
         self.model_disconnected = False
+        self.manager.init_host()
         ctxt = context.get_admin_context()
 
         if self.coordinator:
@@ -126,7 +127,8 @@ class Service(service.Service):
         self.rpcserver = rpc.get_server(target, endpoints)
         self.rpcserver.start()
 
-        self.manager.init_host()
+        self.manager.init_host_with_rpc()
+
         if self.report_interval:
             pulse = loopingcall.FixedIntervalLoopingCall(self.report_state)
             pulse.start(interval=self.report_interval,
diff --git a/manila/tests/scheduler/test_manager.py b/manila/tests/scheduler/test_manager.py
index b1f0fc12ea..a3caccfecc 100644
--- a/manila/tests/scheduler/test_manager.py
+++ b/manila/tests/scheduler/test_manager.py
@@ -89,14 +89,14 @@ class SchedulerManagerTestCase(test.TestCase):
 
         self.assertIsInstance(test_manager.driver, filter.FilterScheduler)
 
-    def test_init_host(self):
+    def test_init_host_with_rpc(self):
 
         self.mock_object(context,
                          'get_admin_context',
                          mock.Mock(return_value='fake_admin_context'))
         self.mock_object(self.manager, 'request_service_capabilities')
 
-        self.manager.init_host()
+        self.manager.init_host_with_rpc()
 
         self.manager.request_service_capabilities.assert_called_once_with(
             'fake_admin_context')
diff --git a/releasenotes/notes/bug-1271568-fix-rpc-init-host-with-rpc-6e76afa553b4f2af.yaml b/releasenotes/notes/bug-1271568-fix-rpc-init-host-with-rpc-6e76afa553b4f2af.yaml
new file mode 100644
index 0000000000..d83830731b
--- /dev/null
+++ b/releasenotes/notes/bug-1271568-fix-rpc-init-host-with-rpc-6e76afa553b4f2af.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    An issue with RPC handling on service restart was addressed by ensuring
+    proper initialization before creating the RPC consumer.  See `bug 1271568
+    <https://bugs.launchpad.net/manila/+bug/1271568>`_ for more details.