[minigraph.py]: Add support for parsing mux cable (#5676)

Find LogicalLinks in minigraph and parse the port information. A new field called `mux_cable` is added to each port's entry in the Port table in config DB:

```
PORT|Ethernet0: {
	"alias": "Ethernet4/1"
	...
	"mux_cable": "true"
}
```

If a mux cable is present on a port, the value for `mux_cable` will be `"true"`. If no mux cable is present, the attribute will either be omitted (default behavior) or set to `"false"`.

src/sonic-config-engine/minigraph.py

@@ -90,6 +90,7 @@ def parse_png(png, hname):
     mgmt_port = ''
     port_speeds = {}
     console_ports = {}
+    mux_cable_ports = {}
     for child in png:
         if child.tag == str(QName(ns, "DeviceInterfaceLinks")):
             for link in child.findall(str(QName(ns, "DeviceLinkBase"))):
@@ -162,7 +163,16 @@ def parse_png(png, hname):
                             elif node.tag == str(QName(ns, "EndDevice")):
                                 mgmt_dev = node.text
 
-    return (neighbors, devices, console_dev, console_port, mgmt_dev, mgmt_port, port_speeds, console_ports)
+        if child.tag == str(QName(ns, "DeviceInterfaceLinks")):
+            for link in child.findall(str(QName(ns, 'DeviceLinkBase'))):
+                if link.find(str(QName(ns, "ElementType"))).text == "LogicalLink":
+                    intf_name = link.find(str(QName(ns, "EndPort"))).text
+                    if intf_name in port_alias_map:
+                        intf_name = port_alias_map[intf_name]
+
+                    mux_cable_ports[intf_name] = "true"
+
+    return (neighbors, devices, console_dev, console_port, mgmt_dev, mgmt_port, port_speeds, console_ports, mux_cable_ports)
 
 def parse_asic_external_link(link, asic_name, hostname):
     neighbors = {}
@@ -831,6 +841,7 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
     port_speed_png = {}
     port_descriptions = {}
     console_ports = {}
+    mux_cable_ports = {}
     syslog_servers = []
     dhcp_servers = []
     ntp_servers = []
@@ -873,7 +884,7 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
             elif child.tag == str(QName(ns, "CpgDec")):
                 (bgp_sessions, bgp_asn, bgp_peers_with_range, bgp_monitors) = parse_cpg(child, hostname)
             elif child.tag == str(QName(ns, "PngDec")):
-                (neighbors, devices, console_dev, console_port, mgmt_dev, mgmt_port, port_speed_png, console_ports) = parse_png(child, hostname)
+                (neighbors, devices, console_dev, console_port, mgmt_dev, mgmt_port, port_speed_png, console_ports, mux_cable_ports) = parse_png(child, hostname)
             elif child.tag == str(QName(ns, "UngDec")):
                 (u_neighbors, u_devices, _, _, _, _, _, _) = parse_png(child, hostname)
             elif child.tag == str(QName(ns, "MetadataDeclaration")):
@@ -1009,6 +1020,11 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
         if port.get('speed') == '100000' and linkmetas.get(alias, {}).get('FECDisabled', '').lower() != 'true':
             port['fec'] = 'rs'
 
+    # If connected to a smart cable, get the connection position
+    for port_name, port in ports.items():
+        if port_name in mux_cable_ports:
+            port['mux_cable'] = mux_cable_ports[port_name]
+
     # set port description if parsed from deviceinfo
     for port_name in port_descriptions:
         # ignore port not in port_config.ini

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

@@ -209,6 +209,28 @@
         <StartDevice>switch-02t1</StartDevice>
         <StartPort>port1</StartPort>
       </DeviceLinkBase>
+      <DeviceLinkBase i:type="LogicalLink">
+        <ElementType>LogicalLink</ElementType>
+        <Bandwidth>10000</Bandwidth>
+        <ChassisInternal>false</ChassisInternal>
+        <EndDevice>switch-t0</EndDevice>
+        <EndPort>fortyGigE0/4</EndPort>
+        <FlowControl>true</FlowControl>
+        <StartDevice>mux-cable</StartDevice>
+        <StartPort>L</StartPort>
+        <Validate>true</Validate>
+      </DeviceLinkBase>
+      <DeviceLinkBase i:type="LogicalLink">
+        <ElementType>LogicalLink</ElementType>
+        <Bandwidth>10000</Bandwidth>
+        <ChassisInternal>false</ChassisInternal>
+        <EndDevice>switch-t0</EndDevice>
+        <EndPort>fortyGigE0/8</EndPort>
+        <FlowControl>true</FlowControl>
+        <StartDevice>mux-cable</StartDevice>
+        <StartPort>U</StartPort>
+        <Validate>true</Validate>
+      </DeviceLinkBase>
     </DeviceInterfaceLinks>
     <Devices>
       <Device i:type="ToRRouter">

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

@@ -346,9 +346,9 @@ class TestCfgGen(TestCase):
         self.assertEqual(
             utils.to_dict(output.strip()),
             utils.to_dict(
-                "{'Ethernet8': {'lanes': '37,38,39,40', 'description': 'Interface description', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/8', 'admin_status': 'up', 'speed': '40000'}, "
+                "{'Ethernet8': {'lanes': '37,38,39,40', 'description': 'Interface description', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/8', 'admin_status': 'up', 'speed': '40000', 'mux_cable': 'true'}, "
                 "'Ethernet0': {'lanes': '29,30,31,32', 'description': 'switch-01t1:port1', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/0', 'admin_status': 'up', 'speed': '10000'}, "
-                "'Ethernet4': {'lanes': '25,26,27,28', 'description': 'fortyGigE0/4', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/4', 'admin_status': 'up', 'speed': '25000'}, "
+                "'Ethernet4': {'lanes': '25,26,27,28', 'description': 'fortyGigE0/4', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/4', 'admin_status': 'up', 'speed': '25000', 'mux_cable': 'true'}, "
                 "'Ethernet108': {'alias': 'fortyGigE0/108', 'pfc_asym': 'off', 'lanes': '81,82,83,84', 'description': 'fortyGigE0/108', 'mtu': '9100'}, "
                 "'Ethernet100': {'alias': 'fortyGigE0/100', 'pfc_asym': 'off', 'lanes': '125,126,127,128', 'description': 'fortyGigE0/100', 'mtu': '9100'}, "
                 "'Ethernet104': {'alias': 'fortyGigE0/104', 'pfc_asym': 'off', 'lanes': '85,86,87,88', 'description': 'fortyGigE0/104', 'mtu': '9100'}, "

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

@@ -2,6 +2,7 @@ import os
 import subprocess
 
 import tests.common_utils as utils
+import minigraph
 
 from unittest import TestCase
 
@@ -159,3 +160,13 @@ class TestCfgGenCaseInsensitive(TestCase):
         output = self.run_script(argument)
         self.assertEqual(output.strip(), "{}")
 
+    def test_mux_cable_parsing(self):
+        result = minigraph.parse_xml(self.sample_graph, port_config_file=self.port_config)
+        
+        expected_mux_cable_ports = ["Ethernet4", "Ethernet8"]
+        port_table = result['PORT']
+        for port_name, port in port_table.items():
+            if port_name in expected_mux_cable_ports:
+                self.assertTrue(port["mux_cable"])
+            else:
+                self.assertTrue("mux_cable" not in port)