[minigraph.py]: Parse peer switch info from minigraph (sonic-net#5869)

* Create new `PEER_SWITCH` table in config DB with info from minigraph
* Add `subtype` field to `DEVICE_METADATA` table and set value to `DualToR` if device is in a dual ToR setup

src/sonic-config-engine/minigraph.py

@@ -65,6 +65,18 @@ def default(self, obj):
             return str(obj)
         return json.JSONEncoder.default(self, obj)
 
+def get_peer_switch_info(link_metadata, devices):
+    peer_switch_table = {}
+    for data in link_metadata.values():
+        if "PeerSwitch" in data:
+            peer_hostname = data["PeerSwitch"]
+            peer_lo_addr = devices[peer_hostname]["lo_addr"] 
+            peer_switch_table[peer_hostname] = {
+                'address_ipv4': peer_lo_addr
+            }
+
+    return peer_switch_table
+
 def parse_device(device):
     lo_prefix = None
     mgmt_prefix = None
@@ -674,16 +686,31 @@ def parse_linkmeta(meta, hname):
             # Cannot find a matching hname, something went wrong
             continue
 
+        has_peer_switch = False
+        upper_tor_hostname = ''
+        lower_tor_hostname = ''
+
         properties = linkmeta.find(str(QName(ns1, "Properties")))
         for device_property in properties.findall(str(QName(ns1, "DeviceProperty"))):
             name = device_property.find(str(QName(ns1, "Name"))).text
             value = device_property.find(str(QName(ns1, "Value"))).text
             if name == "FECDisabled":
                 fec_disabled = value
+            elif name == "GeminiPeeringLink":
+                has_peer_switch = True
+            elif name == "UpperTOR":
+                upper_tor_hostname = value
+            elif name == "LowerTOR":
+                lower_tor_hostname = value
 
         linkmetas[port] = {}
         if fec_disabled:
             linkmetas[port]["FECDisabled"] = fec_disabled
+        if has_peer_switch:
+            if upper_tor_hostname == hname:
+                linkmetas[port]["PeerSwitch"] = lower_tor_hostname
+            else:
+                linkmetas[port]["PeerSwitch"] = upper_tor_hostname
     return linkmetas
 
 
@@ -1001,8 +1028,14 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
         }
     }
 
+    results['PEER_SWITCH'] = get_peer_switch_info(linkmetas, devices)
+
+    if bool(results['PEER_SWITCH']):
+        results['DEVICE_METADATA']['localhost']['subtype'] = 'DualToR'
+
     if is_storage_device:
         results['DEVICE_METADATA']['localhost']['storage_device'] = "true"
+
     # for this hostname, if sub_role is defined, add sub_role in 
     # device_metadata
     if sub_role is not None:

src/sonic-config-engine/tests/simple-sample-graph-case.xml

@@ -286,7 +286,7 @@
         <d3p1:Name i:nil="true" />
         <d3p1:Properties>
           <d3p1:DeviceProperty>
-            <d3p1:Name>DevicePeeringLink</d3p1:Name>
+            <d3p1:Name>GeminiPeeringLink</d3p1:Name>
             <d3p1:Reference i:nil="true" />
             <d3p1:Value>True</d3p1:Value>
           </d3p1:DeviceProperty>

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

@@ -52,6 +52,11 @@ def test_jinja_expression(self):
         output = self.run_script(argument)
         self.assertEqual(output.strip(), 'ToRRouter')
 
+    def test_minigraph_subtype(self):
+        argument = '-m "' + self.sample_graph + '" -v "DEVICE_METADATA[\'localhost\'][\'subtype\']"'
+        output = self.run_script(argument)
+        self.assertEqual(output.strip(), 'DualToR')
+
     def test_additional_json_data(self):
         argument = '-a \'{"key1":"value1"}\' -v key1'
         output = self.run_script(argument)
@@ -174,6 +179,20 @@ def test_minigraph_bgp_mon(self):
         output = self.run_script(argument)
         self.assertEqual(output.strip(), "{}")
 
+    def test_minigraph_peer_switch(self):
+        argument = '-m "' + self.sample_graph + '" -p "' + self.port_config + '" -v "PEER_SWITCH"'
+        expected_table = {
+            'switch2-t0': {
+                'address_ipv4': "25.1.1.10"
+            }
+        }
+
+        output = self.run_script(argument)
+        self.assertEqual(
+            utils.to_dict(output.strip()),
+            expected_table
+        )
+
     def test_mux_cable_parsing(self):
         result = minigraph.parse_xml(self.sample_graph, port_config_file=self.port_config)