python example to change Junos port admin state

change_interface_admin.py

import sys
from ncclient import manager as ncclient
from ncclient.operations.rpc import RPCError
from lxml import etree

### ---------------------------------------------------------------------------
### unix invocation:
### $ python change_interface_admin.py <hostname> <portname> [up|down]
###
### example:
### $ python change_interface_admin.py 192.168.10.21 ge-0/0/1 down
### ---------------------------------------------------------------------------

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

username = "root"
password = "juniper1"

### -----------------------------------------------------------------
### 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

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

def set_port_admin( ncdev, port_name=arg_interface_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
  """

  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'))

  # not trapping on RPCError; should one occur, it could
  # be cause by the calling routine.
  rsp = ncdev.load_configuration(action='set', config=set_config)

  ncdev.commit()
  ncdev.unlock()

  return admin_state

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

def get_port_status( ncdev, port_name=arg_interface_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
    })

  rpc = ncdev.rpc( cmd )
  try:
    ifd_xml = rpc.xpath('//physical-interface')[0]
  except IndexError:
    # indicates that interface does not exist on the device
    return False

  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__":
  ncdev = ncclient.connect(host=arg_host, username=username, password=password, timeout=10, hostkey_verify=False )
  set_port_admin( ncdev )
  ncdev.close_session()