Changes to make lldp show command for multi-npu platforms. (sonic-net#914)

* Changes to make lldp show command for multi-npu platforms.
We will display only front-panel port information.

* Address Review Comments.

* Added Comment

* Fix LGTM error

* Address Review Comments

Author: abdosi

scripts/lldpshow

@@ -25,30 +25,73 @@ import re
 import sys
 import xml.etree.ElementTree as ET
 from tabulate import tabulate
+import argparse
+import sonic_device_util
+from swsssdk import ConfigDBConnector, SonicDBConfig
+BACKEND_ASIC_INTERFACE_NAME_PREFIX = 'Ethernet-BP'
+
+LLDP_INTERFACE_LIST_IN_HOST_NAMESPACE = ''
+LLDP_INSTANCE_IN_HOST_NAMESPACE = ''
+LLDP_DEFAULT_INTERFACE_LIST_IN_ASIC_NAMESPACE = ''
+SPACE_TOKEN = ' '
 
 class Lldpshow(object):
     def __init__(self):
-        self.lldpraw = None
+        self.lldpraw = []
         self.lldpsum = {}
+        self.lldp_interface = []
+        self.lldp_instance = []
         self.err = None
         ### So far only find Router and Bridge two capabilities in lldpctl, so any other capacility types will be read as Other
         ### if further capability type is supported like WLAN, can just add the tag definition here
         self.ctags = {'Router': 'R', 'Bridge': 'B'}
+        SonicDBConfig.load_sonic_global_db_config()
+
+        # For multi-asic platforms we will get only front-panel interface to display
+        namespaces = sonic_device_util.get_all_namespaces()
+        per_asic_configdb = {}
+        for instance_num, front_asic_namespaces in enumerate(namespaces['front_ns']):
+            per_asic_configdb[front_asic_namespaces] = ConfigDBConnector(use_unix_socket_path=True, namespace=front_asic_namespaces)
+            per_asic_configdb[front_asic_namespaces].connect()
+            # Initalize Interface list to be ''. We will do string append of the interfaces below.
+            self.lldp_interface.append(LLDP_DEFAULT_INTERFACE_LIST_IN_ASIC_NAMESPACE)
+            self.lldp_instance.append(instance_num)
+            keys = per_asic_configdb[front_asic_namespaces].get_keys("PORT")
+            for key in keys:
+                if key.startswith(BACKEND_ASIC_INTERFACE_NAME_PREFIX):
+                    continue
+                self.lldp_interface[instance_num] += key + SPACE_TOKEN
 
-    def get_info(self):
+        # LLDP running in host namespace
+        self.lldp_instance.append(LLDP_INSTANCE_IN_HOST_NAMESPACE)
+        self.lldp_interface.append(LLDP_INTERFACE_LIST_IN_HOST_NAMESPACE)
+
+    def get_info(self, lldp_detail_info, lldp_port):
         """
-        use 'lldpctl -f xml' command to gather local lldp detailed information
+        use 'lldpctl' command to gather local lldp detailed information
         """
-        lldp_cmd = 'lldpctl -f xml'
-        p = subprocess.Popen(lldp_cmd, stdout=subprocess.PIPE, shell=True)
-        (output, err) = p.communicate()
-        ## Wait for end of command. Get return returncode ##
-        returncode = p.wait()
-        ### if no error, get the lldpctl result
-        if returncode == 0:
-            self.lldpraw = output
-        else:
-            self.err = err
+        for lldp_instace_num in range(len(self.lldp_instance)):
+            lldp_interface_list = lldp_port if lldp_port is not None else self.lldp_interface[lldp_instace_num]
+            # In detail mode we will pass interface list (only front ports) and get O/P as plain text 
+            # and in table format we will get xml output
+            lldp_cmd = 'sudo docker exec -it lldp{} lldpctl '.format(self.lldp_instance[lldp_instace_num]) + ('-f xml' if not lldp_detail_info else lldp_interface_list)
+            p = subprocess.Popen(lldp_cmd, stdout=subprocess.PIPE, shell=True)
+            (output, err) = p.communicate()
+            ## Wait for end of command. Get return returncode ##
+            returncode = p.wait()
+            ### if no error, get the lldpctl result
+            if returncode == 0:
+                # ignore the output if given port is not present
+                if lldp_port is not None and lldp_port not in output:
+                    continue
+                self.lldpraw.append(output)
+                if lldp_port is not None:
+                    break
+            else:
+                self.err = err
+        
+        if self.err:
+            self.lldpraw = []
 
     def parse_cap(self, capabs):
         """
@@ -64,15 +107,19 @@ class Lldpshow(object):
                     capability += 'O'
         return capability
 
-    def parse_info(self):
+    def parse_info(self, lldp_detail_info):
         """
         Parse the lldp detailed infomation into dict
         """
-        if self.lldpraw is not None:
-            neis = ET.fromstring(self.lldpraw)
+        if lldp_detail_info:
+            return
+        for lldpraw in self.lldpraw:
+            neis = ET.fromstring(lldpraw)
             intfs = neis.findall('interface')
             for intf in intfs:
                 l_intf = intf.attrib['name']
+                if l_intf.startswith(BACKEND_ASIC_INTERFACE_NAME_PREFIX):
+                    continue
                 self.lldpsum[l_intf] = {}
                 chassis = intf.find('chassis')
                 capabs = chassis.findall('capability')
@@ -97,11 +144,17 @@ class Lldpshow(object):
         return sorted(summary, key=alphanum_key)
 
 
-    def display_sum(self):
+    def display_sum(self, lldp_detail_info):
         """
         print out summary result of lldp neighbors
         """
-        if self.lldpraw is not None:
+        # In detail mode output is plain text
+        if self.lldpraw and lldp_detail_info:
+            lldp_output = ''
+            for lldp_detail_output in self.lldpraw:
+                lldp_output += lldp_detail_output
+            print (lldp_output)
+        elif self.lldpraw:
             lldpstatus = []
             print ('Capability codes: (R) Router, (B) Bridge, (O) Other')
             header = ['LocalPort', 'RemoteDevice', 'RemotePortID', 'Capability', 'RemotePortDescr']
@@ -115,11 +168,32 @@ class Lldpshow(object):
             print ('Error:',self.err)
 
 def main():
+    parser  = argparse.ArgumentParser(description='Display the LLDP neighbors',
+                                      version='1.0.0',
+                                      formatter_class=argparse.RawTextHelpFormatter,
+                                      epilog="""
+                                      Examples:
+                                      lldpshow
+                                      lldpshow -d
+                                      lldpshow -d -p Ethernet0
+                                      lldpshow -p Ethernet0
+                                      """)
+
+    parser.add_argument('-d', '--detail', action='store_true', help='LLDP neighbors detail information', default=False)
+    parser.add_argument('-p', '--port', type=str, help='LLDP neighbors detail information for given port', default=None)
+    args = parser.parse_args()
+
+    lldp_detail_info = args.detail
+    lldp_port = args.port
+
+    if lldp_port and not lldp_detail_info:
+        lldp_detail_info = True
+
     try:
         lldp = Lldpshow()
-        lldp.get_info()
-        lldp.parse_info()
-        lldp.display_sum()
+        lldp.get_info(lldp_detail_info, lldp_port)
+        lldp.parse_info(lldp_detail_info)
+        lldp.display_sum(lldp_detail_info)
     except Exception as e:
         print(e.message, file=sys.stderr)
         sys.exit(1)

show/main.py

@@ -1629,13 +1629,13 @@ def lldp():
 @click.option('--verbose', is_flag=True, help="Enable verbose output")
 def neighbors(interfacename, verbose):
     """Show LLDP neighbors"""
-    cmd = "sudo lldpctl"
+    cmd = "sudo lldpshow -d"
 
     if interfacename is not None:
         if get_interface_mode() == "alias":
             interfacename = iface_alias_converter.alias_to_name(interfacename)
 
-        cmd += " {}".format(interfacename)
+        cmd += " -p {}".format(interfacename)
 
     run_command(cmd, display_cmd=verbose)