From 1d00d2c58fb5cd3585e321e3eea54fc8ae0178d8 Mon Sep 17 00:00:00 2001
From: Luis Tomas Bolivar <ltomasbo@redhat.com>
Date: Wed, 14 Jun 2023 16:50:39 +0200
Subject: [PATCH] Retry get_ovs_patch_port_ofport if empty port

It seems sometimes we are getting [] instead of the ofport,
possibly due to a race between creating the interface and
attaching it to the ovs bridge. This ensure it is also
retried in that case

Change-Id: I2f0766c3a018336168c02ab77bbdfc9ed246a150
---
 ovn_bgp_agent/drivers/openstack/utils/ovs.py  | 20 +++++++++++++++++--
 ovn_bgp_agent/drivers/openstack/utils/wire.py | 11 +---------
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/ovn_bgp_agent/drivers/openstack/utils/ovs.py b/ovn_bgp_agent/drivers/openstack/utils/ovs.py
index 5a7df532..0bbd3b6b 100644
--- a/ovn_bgp_agent/drivers/openstack/utils/ovs.py
+++ b/ovn_bgp_agent/drivers/openstack/utils/ovs.py
@@ -18,8 +18,10 @@ from ovsdbapp.backend.ovs_idl import connection
 from ovsdbapp.backend.ovs_idl import idlutils
 from ovsdbapp.schema.open_vswitch import impl_idl as idl_ovs
 import pyroute2
+import tenacity
 
 from ovn_bgp_agent import constants
+from ovn_bgp_agent import exceptions as agent_exc
 import ovn_bgp_agent.privileged.ovs_vsctl
 from ovn_bgp_agent.utils import linux_net
 
@@ -62,10 +64,24 @@ def get_ovs_patch_ports_info(bridge):
     return in_ports
 
 
+@tenacity.retry(
+    retry=tenacity.retry_if_exception_type(agent_exc.PatchPortNotFound),
+    wait=tenacity.wait_fixed(1),
+    stop=tenacity.stop_after_delay(5),
+    reraise=True)
 def get_ovs_patch_port_ofport(patch):
     patch_name = "patch-{}-to-br-int".format(patch)
-    ofport = ovn_bgp_agent.privileged.ovs_vsctl.ovs_cmd(
-        'ovs-vsctl', ['get', 'Interface', patch_name, 'ofport'])[0].rstrip()
+    try:
+        ofport = ovn_bgp_agent.privileged.ovs_vsctl.ovs_cmd(
+            'ovs-vsctl', ['get', 'Interface', patch_name, 'ofport']
+            )[0].rstrip()
+    except Exception:
+        raise agent_exc.PatchPortNotFound(localnet=patch)
+    if ofport == '[]':
+        # NOTE(ltomasbo): there is a chance the patch port interface was
+        # created but not yet added to ovs bridge, therefore it exists but
+        # has an empty ofport. We should retry in this case
+        raise agent_exc.PatchPortNotFound(localnet=patch)
     return ofport
 
 
diff --git a/ovn_bgp_agent/drivers/openstack/utils/wire.py b/ovn_bgp_agent/drivers/openstack/utils/wire.py
index 1d5f63f7..4f0c1e79 100644
--- a/ovn_bgp_agent/drivers/openstack/utils/wire.py
+++ b/ovn_bgp_agent/drivers/openstack/utils/wire.py
@@ -16,7 +16,6 @@ import pyroute2
 
 from oslo_config import cfg
 from oslo_log import log as logging
-import tenacity
 
 from ovn_bgp_agent import constants
 from ovn_bgp_agent.drivers.openstack.utils import ovs
@@ -139,16 +138,8 @@ def unwire_provider_port(routing_tables_routes, port_ips, bridge_device,
         return True
 
 
-@tenacity.retry(
-    retry=tenacity.retry_if_exception_type(agent_exc.PatchPortNotFound),
-    wait=tenacity.wait_fixed(1),
-    stop=tenacity.stop_after_delay(5),
-    reraise=True)
 def _ensure_updated_mac_tweak_flows(localnet, bridge_device, ovs_flows):
-    try:
-        ofport = ovs.get_ovs_patch_port_ofport(localnet)
-    except Exception:
-        raise agent_exc.PatchPortNotFound(localnet=localnet)
+    ofport = ovs.get_ovs_patch_port_ofport(localnet)
     if ofport not in ovs_flows[bridge_device]['in_port']:
         ovs_flows[bridge_device]['in_port'].append(ofport)
         ovs.ensure_mac_tweak_flows(bridge_device,