Python script to admin up/down a Junos interface using the SNMP ifTable index value. Requires the "ncclient" module found at www.github.com/Juniper/ncclient

admin_ifd_byidx.py

# Copyright (c) 1999-2011, Juniper Networks Inc.
# All rights reserved.
# Author: Jeremy Schulman
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#   * Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#
#   * Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#
#   * Neither the name of the Juniper Networks nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY <copyright holder> ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import sys
from ncclient import manager as NC
from lxml import etree

### ---------------------------------------------------------------------------
### unix invocation:
### $ python change_interface_admin.py <hostname> <port_iftbl_idx> [up|down]
###
### example:
### $ python admin_ifd_byidx.py 192.168.10.21 507 down
### ---------------------------------------------------------------------------

CONNECT_TIMEOUT = 5             # 5 seconds to reach device, then error
CONNECT_USERNAME = 'root'       # ! you should change this
CONNECT_PASSWORD = 'juniper1'   # ! you should change this

# The following are exit() codes to indicate failure reason to the
# calling program

ERROR_DEVUNREACHABLE = 1        # unable to connect to device
ERROR_INVALIDPORT = 2           # invalid snmp index
ERROR_ONCHANGE = 3              # when commiting change

# extract program arguments from the command link invocation
# nothing fancy here ...

arg_host = sys.argv[1]
arg_snmp_ifidx = sys.argv[2]
arg_admin_state = False if sys.argv[3] == 'down' else True

# login structure that will be later used to connect
# to the Junos device.

g_login = {
  'host': arg_host,
  'username': CONNECT_USERNAME,
  'password': CONNECT_PASSWORD,
  'timeout': CONNECT_TIMEOUT,
}

### -----------------------------------------------------------------
### build_rpc_cmd - helper function to create XML API command
### -----------------------------------------------------------------

def build_rpc_cmd( rpc_cmd, rpc_args ):
  """
  rpc_cmd - str: command
  rpc_args - dict: key/value rpc arguments
  """
  rpc = etree.Element( rpc_cmd )
  if rpc_args:
    for name, value in rpc_args.items():
      arg = etree.SubElement( rpc, name )
      if value != True: arg.text = value
  return rpc

### -----------------------------------------------------------------
### build_rpc_cmd - helper function to create XML API command
### -----------------------------------------------------------------

def ifd_by_snmpidx( ncdev, ifidx ):

    cmd = build_rpc_cmd('get-snmp-object', {
      'snmp-object-name': 'ifDescr.'+str(ifidx)
    })

    try:
      rsp = ncdev.rpc( cmd )
      ifd = rsp.xpath('.//object-value')[0].text.strip()
    except:
      sys.exit( ERROR_INVALIDPORT )

    return ifd

### -----------------------------------------------------------------
### set_port_admin - change the port admin state
### -----------------------------------------------------------------

def set_port_admin( ncdev, port_name, admin_state=arg_admin_state ):
  """
     Change the admin state of a port.

     ncdev - netconf device object
     port_name - str: name of the interface
     admin_state - True (enable), False (disable)

     Notes: 
     (1) change is exclusive
     (2) exceptions are bubbled up
  """

  try:

    ncdev.lock()

    # disabling a port means setting 'disable' on the port
    set_config = "{cmd} interfaces {name} disable".format(
      name=port_name,
      cmd=('set' if not admin_state else 'delete'))

    rsp = ncdev.load_configuration(action='set', config=set_config)

    ncdev.commit()
    ncdev.unlock()

  except:
    sys.exit( ERROR_ONCHANGE )

  return admin_state

### -----------------------------------------------------------------
### get_port_status - used to retrieve basic port information
### -----------------------------------------------------------------

def get_port_status( ncdev, port_name ):
  """
    get basic port information, returns a dict of information
    or False if the provided interface name (ifd_name) does
    not exist on the device

    ncdev - netconf device object
    port_name - str: the name of the interface, e.g. 'ge-0/0/0'
  """
  cmd = build_rpc_cmd('get-interface-information', {
      'interface-name': port_name,
      'media': True
    })

  try:
    rpc = ncdev.rpc( cmd )
    ifd_xml = rpc.xpath('//physical-interface')[0]
  except IndexError:
    sys.exit( ERROR_INVALIDPORT )

  xpath_item = lambda xpath: ifd_xml.xpath(xpath)[0].text.strip()

  status = {}
  status['name'] = port_name
  status['status'] = xpath_item('oper-status')
  status['admin'] = xpath_item('admin-status')
  status['speed'] = xpath_item('speed')
  status['duplex'] = xpath_item('duplex')
  status['mtu'] = xpath_item('mtu')

  return status

if __name__ == "__main__":

  # do not require ssh hostkey checking

  g_login['hostkey_verify'] = False

  # try to login to the device.  If it fails 
  # for any reason, exit the program with the 
  # given exit code

  try:
    ncdev = NC.connect( **g_login )
  except:
    sys.exit( ERROR_DEVUNREACHABLE )

  ifd_name = ifd_by_snmpidx( ncdev, arg_snmp_ifidx )
  set_port_admin( ncdev, ifd_name )
  ncdev.close_session()