[minigraph] Parse bandwidth for DeviceMgmtLinks (#7744)

Why I did it
The current code skips parsing bandwidth for DeviceMgmtLinks. We have a use case to set the speed for these type of links based on the bandwidth attribute in the minigraph

How to verify it
Ran sonic-cfggen on a minigraph and verified that interface of type DeviceMgmtLink has speed set in the PORT table from the bandwidth attribute in the minigraph

src/sonic-config-engine/minigraph.py

@@ -218,7 +218,7 @@ def parse_png(png, hname, dpg_ecmp_content = None):
                     startdevice = link.find(str(QName(ns, "StartDevice"))).text
                     port_device_map[endport] = startdevice
 
-                if linktype != "DeviceInterfaceLink" and linktype != "UnderlayInterfaceLink":
+                if linktype != "DeviceInterfaceLink" and linktype != "UnderlayInterfaceLink" and linktype != "DeviceMgmtLink":
                     continue
 
                 enddevice = link.find(str(QName(ns, "EndDevice"))).text
@@ -230,12 +230,14 @@ def parse_png(png, hname, dpg_ecmp_content = None):
                 if enddevice.lower() == hname.lower():
                     if endport in port_alias_map:
                         endport = port_alias_map[endport]
+                    if linktype != "DeviceMgmtLink":
                         neighbors[endport] = {'name': startdevice, 'port': startport}
                     if bandwidth:
                         port_speeds[endport] = bandwidth
                 elif startdevice.lower() == hname.lower():
                     if startport in port_alias_map:
                         startport = port_alias_map[startport]
+                    if linktype != "DeviceMgmtLink":
                         neighbors[startport] = {'name': enddevice, 'port': endport}
                     if bandwidth:
                         port_speeds[startport] = bandwidth
@@ -1405,6 +1407,10 @@ def parse_xml(filename, platform=None, port_config_file=None, asic_name=None, hw
                 print("Warning: ignore interface '%s' as it is not in the port_config.ini" % port_name, file=sys.stderr)
                 continue
 
+        # skip management ports
+        if port_name in mgmt_alias_reverse_mapping.keys():
+            continue
+
         ports.setdefault(port_name, {})['speed'] = port_speed_png[port_name]
 
     for port_name, port in list(ports.items()):

src/sonic-config-engine/tests/sample_output/py2/ports.json

@@ -20,6 +20,13 @@
         },
         "OP": "SET"
     },
+    {
+        "PORT_TABLE:Ethernet16": {
+            "speed": "1000",
+            "description": "fortyGigE0/16"
+        },
+        "OP": "SET"
+    },
     {
         "PORT_TABLE:Ethernet12": {
             "speed": "100000",

src/sonic-config-engine/tests/sample_output/py3/ports.json

@@ -26,5 +26,12 @@
             "description": "Interface description"
         },
         "OP": "SET"
+    },
+    {
+        "PORT_TABLE:Ethernet16": {
+            "speed": "1000",
+            "description": "fortyGigE0/16"
+        },
+        "OP": "SET"
     }
 ]

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

@@ -308,6 +308,25 @@
         <StartPort>Ethernet1/33</StartPort>
         <Validate>true</Validate>
       </DeviceLinkBase>
+      <DeviceLinkBase i:type="DeviceMgmtLink">
+        <ElementType>DeviceMgmtLink</ElementType>
+        <Bandwidth>1000</Bandwidth>
+        <EndDevice>switch-t0</EndDevice>
+        <EndPort>fortyGigE0/16</EndPort>
+        <FlowControl>true</FlowControl>
+        <StartDevice>ChassisMTS1</StartDevice>
+        <StartPort>mgmt0</StartPort>
+        <Validate>true</Validate>
+      </DeviceLinkBase>
+      <DeviceLinkBase i:type="DeviceMgmtLink">
+      <ElementType>DeviceMgmtLink</ElementType>
+      <Bandwidth>1000</Bandwidth>
+      <EndDevice>switch-t0</EndDevice>
+      <EndPort>Management1</EndPort>
+      <StartDevice>switch-m0</StartDevice>
+      <StartPort>Management1</StartPort>
+      <Validate>true</Validate>
+      </DeviceLinkBase>
     </DeviceInterfaceLinks>
     <Devices>
       <Device i:type="ToRRouter">
@@ -410,6 +429,18 @@
           <Speed>100000</Speed>
           <Description>Interface description</Description>
         </a:EthernetInterface>
+        <a:EthernetInterface>
+          <ElementType>DeviceInterface</ElementType>
+          <AlternateSpeeds i:nil="true"/>
+          <EnableFlowControl>true</EnableFlowControl>
+          <Index>1</Index>
+          <InterfaceName>fortyGigE0/16</InterfaceName>
+          <InterfaceType i:nil="true"/>
+          <MultiPortsInterface>false</MultiPortsInterface>
+          <PortName>0</PortName>
+          <Priority>0</Priority>
+          <Speed>100000</Speed>
+        </a:EthernetInterface>
       </EthernetInterfaces>
       <FlowControl>true</FlowControl>
       <Height>0</Height>

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

@@ -524,7 +524,7 @@ class TestCfgGen(TestCase):
                 "'Ethernet4': {'lanes': '25,26,27,28', 'description': 'fortyGigE0/4', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/4', 'admin_status': 'up', 'speed': '25000'}, "
                 "'Ethernet8': {'lanes': '37,38,39,40', 'description': 'Interface description', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/8', 'admin_status': 'up', 'speed': '1000'}, "
                 "'Ethernet12': {'lanes': '33,34,35,36', 'fec': 'rs', 'pfc_asym': 'off', 'mtu': '9100', 'alias': 'fortyGigE0/12', 'admin_status': 'up', 'speed': '100000', 'description': 'Interface description'}, "
-                "'Ethernet16': {'alias': 'fortyGigE0/16', 'pfc_asym': 'off', 'lanes': '41,42,43,44', 'description': 'fortyGigE0/16', 'mtu': '9100'}, "
+                "'Ethernet16': {'lanes': '41,42,43,44', 'pfc_asym': 'off', 'description': 'fortyGigE0/16', 'mtu': '9100', 'alias': 'fortyGigE0/16', 'speed': '1000'}, "
                 "'Ethernet20': {'alias': 'fortyGigE0/20', 'pfc_asym': 'off', 'lanes': '45,46,47,48', 'description': 'fortyGigE0/20', 'mtu': '9100'}, "
                 "'Ethernet24': {'alias': 'fortyGigE0/24', 'pfc_asym': 'off', 'lanes': '5,6,7,8', 'description': 'fortyGigE0/24', 'mtu': '9100'}, "
                 "'Ethernet28': {'alias': 'fortyGigE0/28', 'pfc_asym': 'off', 'lanes': '1,2,3,4', 'description': 'fortyGigE0/28', 'mtu': '9100'}, "