From b2dc70ee9bafe3397cf1a6a8ab4553298952e717 Mon Sep 17 00:00:00 2001
From: Lucas Alvares Gomes <lucasagomes@gmail.com>
Date: Thu, 26 Nov 2020 09:51:12 +0000
Subject: [PATCH] [OVN] ovn-metadata-agent: Retry registering Chassis at
 startup

This patch adds a retry mechanism on the register_metadata_agent()
method from the OVN metadata agent to make it more tolerable to the
start up order of the services.

Conflicts:
    neutron/agent/ovn/metadata/agent.py

Change-Id: If0e5a64e5f692c781fb5e6a68b948b611c694ab0
Closes-Bug: #1905700
Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>
(cherry picked from commit 9c236db3bf18854aef5a29a37dd83bff8bda2f7d)
---
 neutron/agent/ovn/metadata/agent.py | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/neutron/agent/ovn/metadata/agent.py b/neutron/agent/ovn/metadata/agent.py
index b02f6f4f7c9..1eeabe241fd 100644
--- a/neutron/agent/ovn/metadata/agent.py
+++ b/neutron/agent/ovn/metadata/agent.py
@@ -15,6 +15,15 @@
 import collections
 import re
 
+from neutron_lib import constants as n_const
+from oslo_concurrency import lockutils
+from oslo_log import log
+from oslo_utils import uuidutils
+from ovsdbapp.backend.ovs_idl import event as row_event
+from ovsdbapp.backend.ovs_idl import vlog
+import six
+import tenacity
+
 from neutron.agent.linux import external_process
 from neutron.agent.linux import ip_lib
 from neutron.agent.linux import iptables_manager
@@ -24,13 +33,6 @@ from neutron.agent.ovn.metadata import server as metadata_server
 from neutron.common.ovn import constants as ovn_const
 from neutron.common import utils
 from neutron.conf.plugins.ml2.drivers.ovn import ovn_conf as config
-from neutron_lib import constants as n_const
-from oslo_concurrency import lockutils
-from oslo_log import log
-from oslo_utils import uuidutils
-from ovsdbapp.backend.ovs_idl import event as row_event
-from ovsdbapp.backend.ovs_idl import vlog
-import six
 
 
 LOG = log.getLogger(__name__)
@@ -231,6 +233,10 @@ class MetadataAgent(object):
 
         proxy.wait()
 
+    @tenacity.retry(
+        wait=tenacity.wait_exponential(
+            max=config.get_ovn_ovsdb_retry_max_interval()),
+        reraise=True)
     def register_metadata_agent(self):
         # NOTE(lucasagomes): db_add() will not overwrite the UUID if
         # it's already set.