[bugfix] vnet ping missing with secondary endpoints empty in priority routes. (sonic-net#2736)

Adding a priority vnet route without secondary endpoints with
custom monitoring does not result in vnet ping session creation.
This change fixes that and adds a test.
Signed-off-by: siqbal1486 <[email protected]>

Author: siqbal1986

orchagent/vnetorch.cpp

@@ -1061,8 +1061,8 @@ bool VNetRouteOrch::selectNextHopGroup(const string& vnet,
     else if (!hasNextHopGroup(vnet, nexthops_primary))
     {
         SWSS_LOG_INFO("Creating next hop group  %s", nexthops_primary.to_string().c_str());
-        setEndpointMonitor(vnet, monitors, nexthops_primary, "", ipPrefix);
-        if (!createNextHopGroup(vnet, nexthops_primary, vrf_obj, ""))
+        setEndpointMonitor(vnet, monitors, nexthops_primary, monitoring, ipPrefix);
+        if (!createNextHopGroup(vnet, nexthops_primary, vrf_obj, monitoring))
         {
             delEndpointMonitor(vnet, nexthops_primary, ipPrefix);
             return false;

tests/test_vnet.py

@@ -3171,6 +3171,33 @@ def test_vnet_orch_22(self, dvs, testlog):
         check_remove_state_db_routes(dvs, 'Vnet12', "100.100.1.67/32")
         #adv should be gone.
         check_remove_routes_advertisement(dvs, "100.100.1.0/24")
+
+        #Add priority route with no secondary enpoints
+        create_vnet_routes(dvs, "100.100.1.71/32", vnet_name, '19.0.0.1,19.0.0.2', ep_monitor='19.0.0.1,19.0.0.2', profile = "test_prf", primary ='19.0.0.1,19.0.0.2',monitoring='custom', adv_prefix='100.100.1.0/24')
+        update_monitor_session_state(dvs, '100.100.1.71/32', '19.0.0.1', 'up')
+        update_monitor_session_state(dvs, '100.100.1.71/32', '19.0.0.2', 'up')
+
+        #verify that no BFD sessions are created.
+        check_del_bfd_session(dvs, ['19.0.0.1'])
+        check_del_bfd_session(dvs, ['19.0.0.2'])
+        time.sleep(2)
+        check_state_db_routes(dvs, vnet_name, "100.100.1.71/32", ['19.0.0.1,19.0.0.2'])
+        # The default Vnet setting does not advertise prefix
+        check_routes_advertisement(dvs, "100.100.1.0/24", "test_prf")
+
+        update_monitor_session_state(dvs, '100.100.1.71/32', '19.0.0.1', 'down')
+        check_state_db_routes(dvs, vnet_name, "100.100.1.71/32", ['19.0.0.2'])
+        # The default Vnet setting does not advertise prefix
+        check_routes_advertisement(dvs, "100.100.1.0/24", "test_prf")
+
+        update_monitor_session_state(dvs, '100.100.1.71/32', '19.0.0.2', 'down')
+        check_remove_state_db_routes(dvs, 'Vnet12', "100.100.1.71/32")
+
+        #remove first route
+        delete_vnet_routes(dvs, "100.100.1.71/32", vnet_name)
+        vnet_obj.check_del_vnet_routes(dvs, 'Vnet12', ["100.100.1.71/32"])
+        check_remove_state_db_routes(dvs, 'Vnet12', "100.100.1.71/32")
+
         delete_vnet_entry(dvs,vnet_name)
         vnet_obj.check_del_vnet_entry(dvs, vnet_name)
         delete_vxlan_tunnel(dvs, tunnel_name)