Repository: sonic-net/sonic-utilities

Issue:
'show ipv6 interface' command crashes on master
**Description**
'show ipv6 interface' command crashes

**Steps to reproduce the issue**
1. Issue the command 'show ipv6 interface'

**Describe the results you received**
admin@sonic:/etc/sonic$ show ipv6 interface
Traceback (most recent call last):
  File "/usr/bin/show", line 12, in <module>
    sys.exit(cli())
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1066, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1066, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/show/main.py", line 1107, in interfaces
    data.append([iface, ifaddresses[0][1], admin + "/" + oper], neighbor_name, neighbor_ip)
TypeError: append() takes exactly one argument (3 given)

**Output of `show version`**

```
SONiC Software Version: SONiC.HEAD.93-dirty-20190930.070254
Distribution: Debian 9.11
Kernel: 4.9.0-9-2-amd64
Build commit: fb666d23
Build date: Mon Sep 30 07:10:43 UTC 2019
Built by: johnar@jenkins-worker-4

Platform: x86_64-dell_s6000_s1220-r0
HwSKU: Force10-S6000
ASIC: broadcom
Serial Number: CN07VJDK282985710002
Uptime: 20:29:47 up 48 min,  1 user,  load average: 0.76, 0.64, 0.63

Docker images:
REPOSITORY                 TAG                             IMAGE ID            SIZE
docker-syncd-brcm          HEAD.93-dirty-20190930.070254   0e89ee4ba898        391MB
docker-syncd-brcm          latest                          0e89ee4ba898        391MB
docker-fpm-frr             HEAD.93-dirty-20190930.070254   89c6a380d5e9        318MB
docker-fpm-frr             latest                          89c6a380d5e9        318MB
docker-sflow               HEAD.93-dirty-20190930.070254   b23adc9f38cf        302MB
docker-sflow               latest                          b23adc9f38cf        302MB
docker-lldp-sv2            HEAD.93-dirty-20190930.070254   68c4e6440ff1        298MB
docker-lldp-sv2            latest                          68c4e6440ff1        298MB
docker-dhcp-relay          HEAD.93-dirty-20190930.070254   3e6d3f86cb37        289MB
docker-dhcp-relay          latest                          3e6d3f86cb37        289MB
docker-database            HEAD.93-dirty-20190930.070254   aff263393d3d        280MB
docker-database            latest                          aff263393d3d        280MB
docker-snmp-sv2            HEAD.93-dirty-20190930.070254   fa84e00fbf8d        334MB
docker-snmp-sv2            latest                          fa84e00fbf8d        334MB
docker-orchagent           HEAD.93-dirty-20190930.070254   775ed521a827        320MB
docker-orchagent           latest                          775ed521a827        320MB
docker-teamd               HEAD.93-dirty-20190930.070254   6c26cb64f61e        302MB
docker-teamd               latest                          6c26cb64f61e        302MB
docker-sonic-telemetry     HEAD.93-dirty-20190930.070254   afd1f6151f17        303MB
docker-sonic-telemetry     latest                          afd1f6151f17        303MB
docker-router-advertiser   HEAD.93-dirty-20190930.070254   ca3561f681c3        281MB
docker-router-advertiser   latest                          ca3561f681c3        281MB
docker-platform-monitor    HEAD.93-dirty-20190930.070254   8ccbf123e0a2        325MB
docker-platform-monitor    latest                          8ccbf123e0a2        325MB
```




Discussion:

Resolving patch:
diff --git a/show/main.py b/show/main.py
--- a/show/main.py
+++ b/show/main.py
@@ -1073,7 +1073,7 @@ def ipv6():
 @ipv6.command()
 def interfaces():
     """Show interfaces IPv6 address"""
-    header = ['Interface', 'IPv6 address/mask', 'Admin/Oper']
+    header = ['Interface', 'IPv6 address/mask', 'Admin/Oper', 'BGP Neighbor', 'Neighbor IP']
     data = []
     bgp_peer = get_bgp_peer()
 
@@ -1104,7 +1104,7 @@ def interfaces():
                     oper = "down"
                 if get_interface_mode() == "alias":
                     iface = iface_alias_converter.name_to_alias(iface)
-                data.append([iface, ifaddresses[0][1], admin + "/" + oper], neighbor_name, neighbor_ip)
+                data.append([iface, ifaddresses[0][1], admin + "/" + oper, neighbor_name, neighbor_ip])
             for ifaddr in ifaddresses[1:]:
                 data.append(["", ifaddr[1], ""])
 


Test patch: