[minigraph] Adjust minigraph parsing per Fine Grained ECMP matchmode changes (#6885)

To adjust config db generated via minigraph per matchmode changes in fine grained ecmp. The changes are done so that nexthop IP based filtering can occur to determine routes as requiring Fine Grained ECMP, in the past the only mode was to use the IP prefix of the route for filtering, with this matchmode change we will use nexthop IP based filtering
Azure/SONiC#727

How I did it
Change will modify config db entry created for FG_NHG to include 'match_mode': 'nexthop-based' so that nexthop IP based filtering can occur to determine routes as requiring Fine Grained ECMP. Changes also remove FG_NHG_PREFIX entry since its not needed under matchmode nexthop-based.

src/sonic-config-engine/minigraph.py

@@ -146,7 +146,6 @@ def formulate_fine_grained_ecmp(version, dpg_ecmp_content, port_device_map, port
         tag = "fgnhg_v6"
 
     port_nhip_map = dpg_ecmp_content['port_nhip_map']
-    nhgaddr = dpg_ecmp_content['nhgaddr']
     nhg_int = dpg_ecmp_content['nhg_int']
 
     nhip_device_map = {port_nhip_map[x]: port_device_map[x] for x in port_device_map
@@ -159,20 +158,17 @@ def formulate_fine_grained_ecmp(version, dpg_ecmp_content, port_device_map, port
     FG_NHG_MEMBER = {ip: {"FG_NHG": tag, "bank": bank} for ip, bank in nhip_bank_map.items()}
     nhip_port_map = dict(zip(port_nhip_map.values(), port_nhip_map.keys()))
 
-    
-
     for nhip, memberinfo in FG_NHG_MEMBER.items():
         if nhip in nhip_port_map:
             memberinfo["link"] = port_alias_map[nhip_port_map[nhip]]
             FG_NHG_MEMBER[nhip] = memberinfo
 
-    FG_NHG_PREFIX = {nhgaddr: {"FG_NHG": tag}}
+    FG_NHG = {tag: {"bucket_size": LCM, "match_mode": "nexthop-based"}}
-    FG_NHG = {tag: {"bucket_size": LCM}}
     for ip in nhip_bank_map:
         neigh_key.append(str(nhg_int + "|" + ip))
     NEIGH = {neigh_key: {"family": family} for neigh_key in neigh_key}
 
-    fine_grained_content = {"FG_NHG_MEMBER": FG_NHG_MEMBER, "FG_NHG": FG_NHG, "FG_NHG_PREFIX": FG_NHG_PREFIX, "NEIGH": NEIGH}
+    fine_grained_content = {"FG_NHG_MEMBER": FG_NHG_MEMBER, "FG_NHG": FG_NHG, "NEIGH": NEIGH}
     return fine_grained_content
 
 def parse_png(png, hname, dpg_ecmp_content = None):
@@ -189,7 +185,6 @@ def parse_png(png, hname, dpg_ecmp_content = None):
     port_device_map = {}
     png_ecmp_content = {}
     FG_NHG_MEMBER = {}
-    FG_NHG_PREFIX = {}
     FG_NHG = {}
     NEIGH = {}
 
@@ -292,12 +287,10 @@ def parse_png(png, hname, dpg_ecmp_content = None):
             for version, content in dpg_ecmp_content.items():  # version is ipv4 or ipv6
                 fine_grained_content = formulate_fine_grained_ecmp(version, content, port_device_map, port_alias_map)  # port_alias_map
                 FG_NHG_MEMBER.update(fine_grained_content['FG_NHG_MEMBER'])
-                FG_NHG_PREFIX.update(fine_grained_content['FG_NHG_PREFIX'])
                 FG_NHG.update(fine_grained_content['FG_NHG'])
                 NEIGH.update(fine_grained_content['NEIGH'])
 
-            png_ecmp_content = {"FG_NHG_PREFIX": FG_NHG_PREFIX, "FG_NHG_MEMBER": FG_NHG_MEMBER, "FG_NHG": FG_NHG,
+            png_ecmp_content = {"FG_NHG_MEMBER": FG_NHG_MEMBER, "FG_NHG": FG_NHG, "NEIGH": NEIGH}
-                            "NEIGH": NEIGH}
 
     return (neighbors, devices, console_dev, console_port, mgmt_dev, mgmt_port, port_speeds, console_ports, mux_cable_ports, is_storage_device, png_ecmp_content)
 
@@ -483,7 +476,6 @@ def parse_dpg(dpg, hname):
                 pcs[pcintfname] = {'members': pcmbr_list, 'min_links': str(int(math.ceil(len(pcmbr_list) * 0.75)))}
         port_nhipv4_map = {}
         port_nhipv6_map = {}
-        nhgaddr = ["", ""]
         nhg_int = ""
         nhportlist = []
         dpg_ecmp_content = {}
@@ -507,20 +499,12 @@ def parse_dpg(dpg, hname):
                         n = list(ipaddress.ip_network(UNICODE_TYPE(subnet_range), False).hosts())
                         if a in n:
                             nhg_int = ip_intfs_map[subnet_range]
-                dwnstrms = child.find(str(QName(ns, "DownstreamSummarySet")))
+
-                for dwnstrm in dwnstrms.findall(str(QName(ns, "DownstreamSummary"))):
+                ipv4_content = {"port_nhip_map": port_nhipv4_map, "nhg_int": nhg_int}
-                    dwnstrmentry = str(ET.tostring(dwnstrm))
+                ipv6_content = {"port_nhip_map": port_nhipv6_map, "nhg_int": nhg_int}
-                    if ("FineGrainedECMPGroupDestination" in dwnstrmentry):
-                        subnet_ip = dwnstrm.find(str(QName(ns1, "Subnet"))).text
-                        truncsubnet_ip = subnet_ip.split("/")[0]
-                        if "." in (truncsubnet_ip):
-                            nhgaddr[0] = subnet_ip
-                        elif ":" in (truncsubnet_ip):
-                            nhgaddr[1] = subnet_ip
-                ipv4_content = {"port_nhip_map": port_nhipv4_map, "nhgaddr": nhgaddr[0], "nhg_int": nhg_int}
-                ipv6_content = {"port_nhip_map": port_nhipv6_map, "nhgaddr": nhgaddr[1], "nhg_int": nhg_int}
                 dpg_ecmp_content['ipv4'] = ipv4_content
                 dpg_ecmp_content['ipv6'] = ipv6_content
+
         vlanintfs = child.find(str(QName(ns, "VlanInterfaces")))
         vlans = {}
         vlan_members = {}
@@ -1490,7 +1474,6 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
 
     if len(png_ecmp_content):
         results['FG_NHG_MEMBER'] = png_ecmp_content['FG_NHG_MEMBER']
-        results['FG_NHG_PREFIX'] = png_ecmp_content['FG_NHG_PREFIX']
         results['FG_NHG'] = png_ecmp_content['FG_NHG']
         results['NEIGH'] = png_ecmp_content['NEIGH']
 

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

@@ -233,9 +233,14 @@ class TestCfgGen(TestCase):
         self.assertEqual(output.strip(), "[('Vlan1000', '192.168.0.1/27'), 'Vlan1000']")
 
     def test_minigraph_ecmp_fg_nhg(self):
-        argument = '-m "' + self.ecmp_graph + '" -p "' + self.mlnx_port_config + '" -v \"FG_NHG.values()|list\"'
+        argument = '-m "' + self.ecmp_graph + '" -p "' + self.mlnx_port_config + '" -v FG_NHG'
         output = self.run_script(argument)
-        self.assertEqual(output.strip(), "[{'bucket_size': 120}, {'bucket_size': 120}]")
+        print(output.strip())
+        self.assertEqual(utils.to_dict(output.strip()), 
+                         utils.to_dict(
+                            "{'fgnhg_v4': {'match_mode': 'nexthop-based', 'bucket_size': 120}, "
+                            "'fgnhg_v6': {'match_mode': 'nexthop-based', 'bucket_size': 120}}"
+                        ))
 
     def test_minigraph_ecmp_members(self):
         argument = '-m "' + self.ecmp_graph + '" -p "' + self.mlnx_port_config + '" -v "FG_NHG_MEMBER.keys()|list|sort"'
@@ -254,12 +259,6 @@ class TestCfgGen(TestCase):
                                          " 'Vlan31|200:200:200:200::2', 'Vlan31|200:200:200:200::3', 'Vlan31|200:200:200:200::4', 'Vlan31|200:200:200:200::5', "
                                          "'Vlan31|200:200:200:200::6', 'Vlan31|200:200:200:200::7', 'Vlan31|200:200:200:200::8', 'Vlan31|200:200:200:200::9']")
 
-    def test_minigraph_ecmp_prefixes(self):
-        argument = '-m "' + self.ecmp_graph + '" -p "' + self.mlnx_port_config + '" -v "FG_NHG_PREFIX.keys()|list|sort"'
-        output = self.run_script(argument)
-        self.assertEqual(output.strip(), "['100.50.25.12/32', 'fc:5::/128']")
-
-        
     def test_minigraph_portchannels(self):
         argument = '-m "' + self.sample_graph_simple + '" -p "' + self.port_config + '" -v PORTCHANNEL'
         output = self.run_script(argument)