From 2cd75e073aa7d949f8842db8d4adbc4d7d2c36ac Mon Sep 17 00:00:00 2001
From: Terry Wilson <twilson@redhat.com>
Date: Fri, 31 Jan 2020 14:49:48 -0600
Subject: [PATCH] OVN Metadata agent gets OVSDB updates for only its Chassis

The metadata agent registers the Chassis table with ovsdb-server
and therefor gets database updates every time *any* Chassis is
updated--even if the update is just a liveness check that updates
nb_cfg.

This patch adds a condition so that metadata agent only gets updates
for the Chassis that it is running on.

Change-Id: I452b7de09312ecea621c4b448cc63f037cad9675
Related-bug: #1861092
---
 neutron/agent/ovn/metadata/agent.py  | 14 ++++++++------
 neutron/agent/ovn/metadata/ovsdb.py  |  3 ++-
 neutron/agent/ovn/metadata/server.py | 10 ++++++----
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/neutron/agent/ovn/metadata/agent.py b/neutron/agent/ovn/metadata/agent.py
index af39467b609..35ff2dfe4f5 100644
--- a/neutron/agent/ovn/metadata/agent.py
+++ b/neutron/agent/ovn/metadata/agent.py
@@ -166,18 +166,20 @@ class MetadataAgent(object):
         self.sync()
 
     def start(self):
-        # Launch the server that will act as a proxy between the VM's and Nova.
-        proxy = metadata_server.UnixDomainMetadataProxy(self.conf)
-        proxy.run()
-
         # Open the connection to OVS database
         self.ovs_idl = ovsdb.MetadataAgentOvsIdl().start()
         self._load_config()
 
+        # Launch the server that will act as a proxy between the VM's and Nova.
+        proxy = metadata_server.UnixDomainMetadataProxy(self.conf,
+                                                        self.chassis)
+        proxy.run()
+
         # Open the connection to OVN SB database.
         self.sb_idl = ovsdb.MetadataAgentOvnSbIdl(
-            [PortBindingChassisEvent(self), ChassisCreateEvent(self),
-                SbGlobalUpdateEvent(self)]).start()
+            chassis=self.chassis,
+            events=[PortBindingChassisEvent(self), ChassisCreateEvent(self),
+                    SbGlobalUpdateEvent(self)]).start()
 
         # Do the initial sync.
         self.sync()
diff --git a/neutron/agent/ovn/metadata/ovsdb.py b/neutron/agent/ovn/metadata/ovsdb.py
index 965670f4d18..703edc68042 100644
--- a/neutron/agent/ovn/metadata/ovsdb.py
+++ b/neutron/agent/ovn/metadata/ovsdb.py
@@ -27,7 +27,7 @@ class MetadataAgentOvnSbIdl(ovsdb_monitor.OvnIdl):
 
     SCHEMA = 'OVN_Southbound'
 
-    def __init__(self, events=None):
+    def __init__(self, chassis, events=None):
         connection_string = config.get_ovn_sb_connection()
         ovsdb_monitor._check_and_set_ssl_files(self.SCHEMA)
         helper = self._get_ovsdb_helper(connection_string)
@@ -37,6 +37,7 @@ class MetadataAgentOvnSbIdl(ovsdb_monitor.OvnIdl):
             helper.register_table(table)
         super(MetadataAgentOvnSbIdl, self).__init__(
             None, connection_string, helper)
+        self.tables['Chassis'].condition = [['name', '==', chassis]]
         if events:
             self.notify_handler.watch_events(events)
 
diff --git a/neutron/agent/ovn/metadata/server.py b/neutron/agent/ovn/metadata/server.py
index 10bee18ca40..8ab2f71bb93 100644
--- a/neutron/agent/ovn/metadata/server.py
+++ b/neutron/agent/ovn/metadata/server.py
@@ -44,8 +44,9 @@ MODE_MAP = {
 
 class MetadataProxyHandler(object):
 
-    def __init__(self, conf):
+    def __init__(self, conf, chassis=''):
         self.conf = conf
+        self.chassis = chassis
         self.subscribe()
 
     def subscribe(self):
@@ -56,7 +57,7 @@ class MetadataProxyHandler(object):
     def post_fork_initialize(self, resource, event, trigger, payload=None):
         # We need to open a connection to OVN SouthBound database for
         # each worker so that we can process the metadata requests.
-        self.sb_idl = ovsdb.MetadataAgentOvnSbIdl().start()
+        self.sb_idl = ovsdb.MetadataAgentOvnSbIdl(chassis=self.chassis).start()
 
     @webob.dec.wsgify(RequestClass=webob.Request)
     def __call__(self, req):
@@ -161,8 +162,9 @@ class MetadataProxyHandler(object):
 
 class UnixDomainMetadataProxy(object):
 
-    def __init__(self, conf):
+    def __init__(self, conf, chassis=''):
         self.conf = conf
+        self.chassis = chassis
         agent_utils.ensure_directory_exists_without_file(
             cfg.CONF.metadata_proxy_socket)
 
@@ -187,7 +189,7 @@ class UnixDomainMetadataProxy(object):
     def run(self):
         self.server = agent_utils.UnixDomainWSGIServer(
             'networking-ovn-metadata-agent')
-        self.server.start(MetadataProxyHandler(self.conf),
+        self.server.start(MetadataProxyHandler(self.conf, self.chassis),
                           self.conf.metadata_proxy_socket,
                           workers=self.conf.metadata_workers,
                           backlog=self.conf.metadata_backlog,