[minigraph] Enhanced parser to parse interface name for static route …

…nexthop (sonic-net#9707)

What I did:-

Enhanced minigraph parser to parse interface name associated with static route nexthop

Why I did:-

One of the use case to support interface name is Chassis Packet. For Chassis Packet we have Static Routes configured to route traffic across line-card. If the FRR programs static route without the interface name then in case if the ip interface that is associated with the nexthop goes down FRR resolves static route nexthop over the default route as we have FRR config ip nht-resolve-via-default which causes undesired behavior. Having interface name with Static Route prevents recursive lookup on default route.

How I verify:

Updated unit-test cases
Manual verification

src/sonic-config-engine/minigraph.py

@@ -510,10 +510,11 @@ def parse_dpg(dpg, hname):
                     elif ":" in ipnhaddr:
                         port_nhipv6_map[ipnhfmbr] = ipnhaddr
                 elif ipnh.find(str(QName(ns, "Type"))).text == 'StaticRoute':
-                    prefix = ipnh.find(str(QName(ns, "AttachTo"))).text
+                    prefix = ipnh.find(str(QName(ns, "AssociatedTo"))).text
+                    ifname = ipnh.find(str(QName(ns, "AttachTo"))).text
                     nexthop = ipnh.find(str(QName(ns, "Address"))).text
                     advertise = ipnh.find(str(QName(ns, "Advertise"))).text
-                    static_routes[prefix] = {'nexthop': nexthop, 'advertise': advertise}
+                    static_routes[prefix] = {'nexthop': nexthop, 'ifname': ifname, 'advertise': advertise}
 
             if port_nhipv4_map and port_nhipv6_map:
                 subnet_check_ip = list(port_nhipv4_map.values())[0]

src/sonic-config-engine/tests/sample-chassis-packet-lc-graph.xml

@@ -121,8 +121,9 @@
 	   <IPNextHop>
 	    <ElementType>IPNextHop</ElementType>
 	    <Name i:nil="true"/>
-	    <AttachTo>8.0.0.1/32</AttachTo>
+	    <AssociatedTo>8.0.0.1/32</AssociatedTo>
 	    <Address>192.168.1.2,192.168.2.2</Address>
+	    <AttachTo>PortChannel40,PortChannel50</AttachTo>
 	    <Type>StaticRoute</Type>
         <Advertise>false</Advertise>
         </IPNextHop>
@@ -212,8 +213,9 @@
 	<IPNextHop>
 	  <ElementType>IPNextHop</ElementType>
 	  <Name i:nil="true"/>
-	  <AttachTo>8.0.0.1/32</AttachTo>
-	  <Address>192.168.1.2,192.168.2.2</Address>
+	    <AssociatedTo>8.0.0.1/32</AssociatedTo>
+	    <Address>192.168.1.2,192.168.2.2</Address>
+	    <AttachTo>PortChannel40,PortChannel50</AttachTo>
       <Type>StaticRoute</Type>
       <Advertise>false</Advertise>
         </IPNextHop>

src/sonic-config-engine/tests/test_cfggen.py

@@ -904,14 +904,14 @@ def test_minigraph_bgp_packet_chassis_static_route(self):
         output = self.run_script(argument)
         self.assertEqual(
             utils.to_dict(output.strip()),
-            utils.to_dict("{'8.0.0.1/32': {'nexthop': '192.168.1.2,192.168.2.2', 'advertise':'false'}}")
+            utils.to_dict("{'8.0.0.1/32': {'nexthop': '192.168.1.2,192.168.2.2', 'ifname': 'PortChannel40,PortChannel50', 'advertise':'false'}}")
         )
 
         argument = '-m "' + self.packet_chassis_graph + '" -p "' + self.packet_chassis_port_ini + '" -n "' + "asic1" + '" -v "STATIC_ROUTE"'
         output = self.run_script(argument)
         self.assertEqual(
             utils.to_dict(output.strip()),
-            utils.to_dict("{'8.0.0.1/32': {'nexthop': '192.168.1.2,192.168.2.2', 'advertise':'false'}}")
+            utils.to_dict("{'8.0.0.1/32': {'nexthop': '192.168.1.2,192.168.2.2', 'ifname': 'PortChannel40,PortChannel50', 'advertise':'false'}}")
         )
 
     def test_minigraph_bgp_packet_chassis_vlan_subintf(self):