#!/bin/env python
#md5sum="1399d8ca81cf1c7b565d13a003be4c0f"

# The above is the (embedded) md5sum of this file taken without this line, 
# can be # created this way if using a bash shell: 
# f=poap_ng.py ; cat $f | sed '/^#md5sum/d' > $f.md5 ; sed -i "s/^#md5sum=.*/#md5sum=\"$(md5sum $f.md5 | sed 's/ .*//')\"/" $f
# This way this script's integrity can be checked in case you do not trust
# tftp's ip checksum. This integrity check is done by /isan/bin/poap.bin).
# The integrity of the files downloaded later (images, config) is checked 
# by downloading the corresponding file with the .md5 extension and is
# done by this script itself.
# Version History
# ---------------------------------------------------------------------------
# Version 1.1 - Integrating both static mode and serial_number mode for POAP 
#   to obtain the config file. This may be required for Smart Licensing token 
#   config automation requirement.
#   User can now simultaneously define serial_number based config and static
#   config download. POAP will try to download <serial_number.cfg> by default,
#   and if the file does not exists in the tftp server, then it will retry 
#   again specified by serial_number_retry value. If still config downlaod 
#   fails POAP will fallback to downlaod the static config(golden.cfg). 
#   User to set retry count as per their network conditions.
#   Please also check the accompanying new script sl_token_preprovision.py,
#   which can be used for token config automation in smart licensing feature.

import os
import time
import re
import sys
import syslog
import shutil
import signal
import string
import traceback

# **** Here are all variables that parametrize this script **** 
# *************************************************************

# system and kickstart images, configuration: location on server (src) and target (dst)
image_version       = "6.2.1.23"
n3k_image_version   = "5.0.3.U5.1"
n5k_image_version   = "5.2.1.N1.2a"
image_dir_src       = "/tftpb" # part of path to remove during copy
n3k_system_image_src      = "n3000-uk9.%s.bin"      % n3k_image_version
n7k_system_image_src      = "n7000-s1-dk9.%s.bin"   % image_version
n5k_system_image_src      = "n5000-uk9.%s.bin"      % n5k_image_version
n3k_kickstart_image_src     = "n3000-uk9-kickstart.%s.bin"      % n3k_image_version
n7k_kickstart_image_src     = "n7000-s1-kickstart.%s.bin"   % image_version
n5k_kickstart_image_src     = "n5000-uk9-kickstart.%s.bin"  % n5k_image_version
config_file_src     = "/tftpb/poap.cfg"
config_file_src_static = "/tftpb/golden.cfg"
image_dir_dst       = "bootflash:"
system_image_dst        = "%s/system.img"      %  image_dir_dst
kickstart_image_dst     = "%s/kickstart.img"   %  image_dir_dst
# the copy scheduled-config command will copy to persistent location
config_file_dst     = "volatile:poap.cfg" 
md5sum_ext_src      = "md5" # extension of file containing md5sum of the one without ext.
# there is no md5sum_ext_dst because one the target it is a temp file
required_space = 250000 # Required space on /bootflash (for config and kick/system images)

# Protocols available to download are scp/tftp/ftp/sftp 
protocol="scp" # protocol to use to download images/config

# Host name and user credentials
username = "user" # tftp server account
ftp_username = "user" # ftp server account
password = "password"
hostname = "192.168.1.1"

# vrf info
vrf = "management"
if os.environ.has_key('POAP_VRF'):
    vrf=os.environ['POAP_VRF']

# Timeout info (from biggest to smallest image, should be f(image-size, protocol))
system_timeout    = 2100 
kickstart_timeout = 900  
config_timeout    = 120 
md5sum_timeout    = 120  

# POAP can use 3 modes to obtain the config file.
# - 'static' - filename is static
# - 'serial_number' - switch serial number is part of the filename
# - 'location' - CDP neighbor of interface on which DHCPDISCOVER arrived
#                is part of filename
# serial_number case:
# if serial-number is abc123, filename for config should be abc123.cfg
# file is present in location /tftp/
# the above requires populating config_file_src = "/tftp/.cfg" 
# location case:
# if cdp neighbor's device_id=abc and port_id=111, then filename is config_file_src.abc_111
# Note: the next line can be overwritten by command-line arg processing later
# static case: 
# POAP will try to copy from config_file_src_static. This variable should be changed
# to reflect name of any static config file for POAP.(Not mandatory for serial_number case).
# serial_number_retry signifies the number of retries for serial_number case.
# 0 means no retry. 
# Warning: Setting serial_number_retry to a high value can potentially cause 
# lag in bootup due to large number of copy retries.

serial_number_retry = 0
config_file_type = "serial_number"

# parameters passed through environment:
pid=""
if os.environ.has_key('POAP_PID'):
    pid=os.environ['POAP_PID']
serial_number=None
if os.environ.has_key('POAP_SERIAL'):
    serial_number=os.environ['POAP_SERIAL']
cdp_interface=None
if os.environ.has_key('POAP_INTF'):
    cdp_interface=os.environ['POAP_INTF']

# will append date/timespace into the name later
log_filename = "/bootflash/poap.log"
t=time.localtime()
now="%d_%d_%d" % (t.tm_hour, t.tm_min, t.tm_sec)

# **** end of parameters **** 
# *************************************************************

# ***** argv parsing and online help (for test through cli) ******
# ****************************************************************

cl_cdp_interface=None  # Command Line version of cdp-interface
cl_serial_number=None  # can overwrite the corresp. env var
cl_protocol=None       # can overwride the script's default
cl_download_only=None  # dont write boot variables

def parse_args(argv, help=None):
    global cl_cdp_interface, cl_serial_number, cl_protocol, protocol, cl_download_only
    while argv:
        x = argv.pop(0)
        # not handling duplicate matches...
        if cmp('cdp-interface'[0:len(x)], x) == 0:
          try: cl_cdp_interface = argv.pop(0)
          except: 
             if help: cl_cdp_interface=-1
          if len(x) != len('cdp-interface') and help: cl_cdp_interface=None
          continue
        if cmp('serial-number'[0:len(x)], x) == 0:
          try: cl_serial_number = argv.pop(0)
          except: 
            if help: cl_serial_number=-1
          if len(x) != len('serial-number') and help: cl_serial_number=None
          continue
        if cmp('protocol'[0:len(x)], x) == 0:
          try: cl_protocol = argv.pop(0); 
          except: 
            if help: cl_protocol=-1
          if len(x) != len('protocol') and help: cl_protocol=None
          if cl_protocol: protocol=cl_protocol
          continue
        if cmp('download-only'[0:len(x)], x) == 0:
          cl_download_only = 1
          continue
        print "Syntax Error|invalid token:", x
        exit(-1)
  

########### display online help (if asked for) #################
nb_args = len(sys.argv)
if nb_args > 1:
  m = re.match('__cli_script.*help', sys.argv[1])
  if m:
    # first level help: display script description
    if sys.argv[1] == "__cli_script_help":
      print "loads system/kickstart images and config file for POAP\n"
      exit(0)
    # argument help
    argv = sys.argv[2:]
    # dont count last arg if it was partial help (no-space-question-mark)
    if sys.argv[1] == "__cli_script_args_help_partial":
      argv = argv[:-1]
    parse_args(argv, "help")
    if cl_serial_number==-1:
      print "WORD|Enter the serial number"
      exit(0)
    if cl_cdp_interface==-1:
      print "WORD|Enter the CDP interface instance"
      exit(0)
    if cl_protocol==-1:
      print "tftp|Use tftp for file transfer protocol"
      print "ftp|Use ftp for file transfer protocol"
      print "scp|Use scp for file transfer protocol"
      exit(0)
    if not cl_serial_number:
      print "serial-number|The serial number to use for the config filename"
    if not cl_cdp_interface:
      print "cdp-interface|The CDP interface to use for the config filename"
    if not cl_protocol:
      print "protocol|The file transfer protocol"
    if not cl_download_only:
      print "download-only|stop after download, dont write boot variables"
    print "<CR>|Run it (use static name for config file)"
    # we are done
    exit(0)

# *** now overwrite env vars with command line vars (if any given)
# *** this can be used for testing the script using the command line

argv = sys.argv[1:]
parse_args(argv)
if cl_serial_number: 
    serial_number=cl_serial_number
    config_file_type = "serial_number"
if cl_cdp_interface: 
    cdp_interface=cl_cdp_interface
    config_file_type = "location"
if cl_protocol: 
    protocol=cl_protocol

# figure out what kind of box we have (to download the correct images)
from cisco import cli
r=cli("show version")
# n3k, n5k and n6k cli returns a two element list, second one is the result string
if len(r)==2:
    lines=r[1].split("\n")
else:
    lines=r.split("\n")

idx = [i for i, line in enumerate(lines) if re.search('^.*cisco.*Chassis.*$', line)]
if re.match(".*Nexus7.*",lines[idx[0]]): 
    box="n7k"
elif re.match(".*Nexus3.*",lines[idx[0]]): 
    box="n3k"
elif re.match(".*Nexus5.*",lines[idx[0]]): 
    box="n5k"
elif re.match(".*Nexus6.*",lines[idx[0]]): 
    box="n6k"
elif re.match(".*Nexus 7.*",lines[idx[0]]):
    box="titan"

print "box is", box

if box!="n7k":
    from cisco import transfer


# setup log file and associated utils
try:
    log_filename = "%s.%s" % (log_filename, now)
except Exception as inst:
    print inst
poap_log_file = open(log_filename, "w+")

def poap_log (info):
    poap_log_file.write(info)
    poap_log_file.write("\n")
    poap_log_file.flush()
    print info
    syslog.syslog(9, info)
    sys.stdout.flush()

def poap_log_close ():
    poap_log_file.close()

def abort_cleanup_exit () : 
    poap_log("INFO: cleaning up")
    poap_log_close()
    exit(-1)


# some argument sanity checks:
# sanity check for serial number is removed for smart-licensing requirement


if config_file_type == "location" and cdp_interface == None: 
    poap_log("ERR: interface required (to derive config name) but none given")
    exit(-1)

# Get final image name based on actual box
# The variable box is the box platform, like n7k, n3k, n5k, n6k.
# This is to generate the kickstart or system image src variable names defined
# in the beginning of the file, e.g., n3k_system_image_src
# For different sup, e.g., sup1, sup2, assign the correct image name to image
# src variable
system_image_src = eval("%s_%s" %(box , "system_image_src"), globals())
kickstart_image_src = eval("%s_%s" %(box , "kickstart_image_src"), globals())

# images are copied to temporary location first (dont want to 
# overwrite good images with bad ones).
system_image_dst_tmp    = "%s/system.img%s"    % (image_dir_dst, ".new")
kickstart_image_dst_tmp = "%s/kickstart.img%s" % (image_dir_dst, ".new")

system_image_src    = "%s/%s" % (image_dir_src, system_image_src)
kickstart_image_src = "%s/%s" % (image_dir_src, kickstart_image_src)

# setup the cli session
cli("no terminal color persist");
cli("terminal dont-ask");

# utility functions
def run_cli (cmd):
    if("password" not in cmd):
        poap_log("CLI : %s" % cmd)
    if box=="n7k":
        r=cli(cmd)
    else:
        r=cli(cmd)[1]

    return r

def rm_rf (filename): 
    try: cli("delete %s" % filename)
    except: pass

# signal handling
def sig_handler_no_exit (signum, frame) : 
    poap_log("INFO: SIGTERM Handler while configuring boot variables")

def sigterm_handler (signum, frame): 
    poap_log("INFO: SIGTERM Handler") 
    abort_cleanup_exit()
    exit(1)

signal.signal(signal.SIGTERM, sigterm_handler)

# transfers file, return True on success; on error exits unless 'fatal' is False in which case we return False
def doCopy(protocol = "", host = "", source = "", dest = "", vrf = "management", login_timeout=10, user = "", password = "", fatal=True):
    rm_rf(dest)

    # modify source paths (tftp does not like full paths)
    global username, ftp_username
    if protocol=="tftp": 
      source=source[len(image_dir_src):]
    if protocol=="ftp": 
      username=ftp_username
      source=source[len(image_dir_src):]

    if box=="n7k":
        cmd="terminal password %s ; copy %s://%s@%s/%s %s vrf %s" % (password, protocol, username, host, source, dest, vrf)
        poap_log("Command executed: terminal password ****** ; copy %s://%s@%s/%s %s vrf %s" % (protocol, username, host, source, dest, vrf))
        #print cmd
        try: run_cli(cmd)
        except:
            poap_log("WARN: Copy Failed: %s" % str(sys.exc_value).strip('\n\r') )
            if fatal:
                poap_log("ERR : aborting")
                abort_cleanup_exit()
                exit(1)
            return False
        return True
    else:
        try:
            transfer(protocol, host, source, dest, vrf, login_timeout, username, password)
        except Exception as inst:
            poap_log("WARN: Copy Failed: %s" % inst)
            if fatal:
                poap_log("ERR : aborting")
                abort_cleanup_exit()
                exit(1)
            return False
        return True


def get_md5sum_src (file_name):
    md5_file_name_src = "%s.%s" % (file_name, md5sum_ext_src)
    md5_file_name_dst = "volatile:%s.poap_md5" % os.path.basename(md5_file_name_src)
    rm_rf(md5_file_name_dst)

    ret=doCopy(protocol, hostname, md5_file_name_src, md5_file_name_dst, vrf, md5sum_timeout, username, password, False)
    if ret == True:
        r=run_cli("show file %s" % md5_file_name_dst)
        match = re.search("^([0-9a-f]+)\s+.*", r, re.MULTILINE)
        if match:
            sum = match.group(1)
        else:
            poap_log("INFO: Unable to get the md5 sum")
            return None
        poap_log("INFO: md5sum %s (.md5 file)" % sum)
        rm_rf(md5_file_name_dst)
        return sum
    return None
    # if no .md5 file, and text file, could try to look for an embedded checksum (see below)


def check_embedded_md5sum (filename):
    # extract the embedded checksum
    sum_emb=run_cli("show file %s | grep '^#md5sum' | head lines 1 | sed 's/.*=//'" % filename).strip('\n')
    if sum_emb == "":
        poap_log("INFO: no embedded checksum")
        return None
    poap_log("INFO: md5sum %s (embedded)" % sum_emb)

    # remove the embedded checksum (create temp file) before we recalculate
    cmd="show file %s exact | sed '/^#md5sum=/d' > volatile:poap_md5" % filename
    run_cli(cmd)
    # calculate checksum (using temp file without md5sum line)
    sum_dst=run_cli("show file volatile:poap_md5 md5sum").strip('\n')
    poap_log("INFO: md5sum %s (recalculated)" % sum_dst)
    try: run_cli("delete volatile:poap_md5")
    except: pass
    if sum_emb != sum_dst:
        poap_log("ERR : MD5 verification failed for %s" % filename)
        abort_cleanup_exit()

    return None

def get_md5sum_dst (filename):
    sum=run_cli("show file %s md5sum" % filename).strip('\n')
    poap_log("INFO: md5sum %s (recalculated)" % sum)
    return sum  

def check_md5sum (filename_src, filename_dst, lname):
    md5sum_src = get_md5sum_src(filename_src)
    if md5sum_src: # we found a .md5 file on the server
        md5sum_dst = get_md5sum_dst(filename_dst)
        if md5sum_dst != md5sum_src:
             poap_log("ERR : MD5 verification failed for %s! (%s)" % (lname, filename_dst))
             abort_cleanup_exit()

# Will run our CLI command to test MD5 checksum and if files are valid images
# This check is also performed while setting the boot variables, but this is an
# additional check

def get_md5_status (msg):
   
    lines=msg.split("\n") 
    for line in lines:
        index=line.find("MD5")
        if (index!=-1):
            status=line[index+17:]
            return status

def get_version (msg):
   
    lines=msg.split("\n") 
    for line in lines:
        index=line.find("MD5")
        if (index!=-1):
            status=line[index+17:]

        index=line.find("kickstart:")
        if (index!=-1): 
            index=line.find("version")
            ver=line[index:]
            return ver

        index=line.find("system:")
        if (index!=-1):
            index=line.find("version")
            ver=line[index:]
            return ver
    
def get_image_version(image):
    version = "Unable to retrieve"
    try:
        out = cli("show version image %s" % image)
        out = out[1]
        # This is a Hack; once the "plugin based. failed to get image swid"
        # is fixed this  expect part can be removed.
    except SyntaxError, err:
        out = err.msg

    match = re.search("image name:\s+([a-zA-Z\.\-0-9]+)\n", out, re.MULTILINE)
    if match:
        split_image = match.group(1).split('.')
        version = ".".join(split_image[1:len(split_image) -1])

    return version

def verify_images ():

    if box=="n5k":
        # This is to fix the n5k system image bug
        kick_v=get_image_version(kickstart_image_dst)
        sys_v=get_image_version(system_image_dst)
        if kick_v != sys_v: 
            poap_log("ERR : Image version mismatch. (kickstart : %s) (system : %s)" % (kick_v, sys_v))
            abort_cleanup_exit()
        return True

    kick_cmd="show version image %s" % kickstart_image_dst
    sys_cmd="show version image %s" % system_image_dst

    kick_msg=run_cli(kick_cmd)
    sys_msg=run_cli(sys_cmd)

    # n3k, n6k images do not provide md5 information
    if box=="n7k":
        kick_s=get_md5_status(kick_msg)
        sys_s=get_md5_status(sys_msg)    

    kick_v=get_version(kick_msg)
    sys_v=get_version(sys_msg)
    
    if box=="n7k": 
        print "MD5 status: %s and %s" % (kick_s, sys_s)
        if (kick_s == "Passed" and sys_s == "Passed"):
            # MD5 verification passed
            if(kick_v != sys_v): 
                poap_log("ERR : Image version mismatch. (kickstart : %s) (system : %s)" % (kick_v, sys_v))
                abort_cleanup_exit()
        else:
            poap_log("ERR : MD5 verification failed!")
            poap_log("%s\n%s" % (kick_msg, sys_msg))
            abort_cleanup_exit()
        poap_log("INFO: Verification passed. (kickstart : %s) (system : %s)" % (kick_v, sys_v))
        return True
    else:
        if kick_v != sys_v: 
            poap_log("ERR : Image version mismatch. (kickstart : %s) (system : %s)" % (kick_v, sys_v))
            abort_cleanup_exit()
    
        return True
        

# get config file from server
def get_config (config_file_type, serial_number_retry):
    
    if config_file_type == "serial_number":
        if (serial_number_retry > 25):
            poap_log("WARNING: High serial_number_retry detected. Retries may take few minutes.")
        rc = doCopy (protocol, hostname, config_file_src, config_file_dst, vrf, config_timeout, username, password, False)
# here the retries will start if initial copy failed.
        if (rc == True):
            poap_log("INFO: Completed Copy of Config File")
        else:
            while (serial_number_retry > 0):
                rc = doCopy (protocol, hostname, config_file_src, config_file_dst, vrf, config_timeout, username, password, False)
                if (rc == True):
                    poap_log("INFO: Completed Copy of Config File")
                    serial_number_retry = 1             #this is to terminate the while loop.
                serial_number_retry = serial_number_retry - 1
            if (rc != True):    
                poap_log("INFO: Serial number case failed. Trying static case.")
                rc = doCopy(protocol, hostname, config_file_src_static, config_file_dst, vrf, config_timeout, username, password)
                if (rc == True):
                    poap_log("INFO: Completed copy of config file through static")
                    config_file_type = "static"             #config_file_type is changed for md5 checksum to be picked up
    else:
        rc = doCopy(protocol, hostname, config_file_src_static, config_file_dst, vrf, config_timeout, username, password)
        if (rc == True):
            poap_log("INFO: Completed copy of config file through static")
        
    # get file's md5 from server (if any) and verify it, failure is fatal (exit)
    if config_file_type == "static":
        check_md5sum (config_file_src_static, config_file_dst, "config file")
    else:
        check_md5sum (config_file_src, config_file_dst, "config file")

# get system image file from server
def get_system_image ():

    doCopy (protocol, hostname, system_image_src, system_image_dst_tmp, vrf, system_timeout, username, password)  
    poap_log("INFO: Completed Copy of System Image" ) 
    
    # get file's md5 from server (if any) and verify it, failure is fatal (exit)
    check_md5sum (system_image_src, system_image_dst_tmp, "system image")
    run_cli ("move %s %s" % (system_image_dst_tmp, system_image_dst))


# get kickstart image file from server
def get_kickstart_image ():

    doCopy (protocol, hostname, kickstart_image_src, kickstart_image_dst_tmp, vrf, kickstart_timeout, username, password)  
    poap_log("INFO: Completed Copy of Kickstart Image") 
    
    # get file's md5 from server (if any) and verify it, failure is fatal (exit)
    check_md5sum (kickstart_image_src, kickstart_image_dst_tmp, "kickstart image")
    run_cli ("move %s %s" % (kickstart_image_dst_tmp, kickstart_image_dst))


def wait_box_online ():
	
    while 1:
#        r=run_cli("show system internal ascii-cfg event-history | grep BOX_ONLINE")
        r=int(run_cli("show system internal platform internal info | grep box_online | sed 's/[^0-9]*//g'").strip('\n'))
        if r: break
        else: time.sleep(5)
        poap_log("INFO: Waiting for box online...") 


# install (make persistent) images and config 
def install_it (): 
    global cl_download_only
    if cl_download_only: exit(0)
    timeout = -1

    # make sure box is online
    if box=="n7k": wait_box_online()

    poap_log("INFO: Setting the boot variables")
    try:
        run_cli ("config terminal ; boot kickstart %s" % kickstart_image_dst)
        run_cli ("config terminal ; boot system %s" % system_image_dst)
        run_cli ("copy running-config startup-config")
        run_cli ('copy %s scheduled-config' % config_file_dst)
    except:
        poap_log("ERR : setting bootvars or copy run start failed!")
        poap_log("ERR: msg: %s" % str(sys.exc_value).strip('\n\r'))
        traceback.print_exc(file=sys.stdout)
        sys.stdout.flush()
        abort_cleanup_exit()
    poap_log("INFO: Configuration successful")

        
# Verify if free space is available to download config, kickstart and system images
def verify_freespace (): 
    out=run_cli("dir bootflash:")
    match = re.search("^\s+([0-9]+)\s+bytes\s+free$", out, re.MULTILINE)
    if match:
        freespace=int(match.group(1))/1024
    else:
        poap_log("ERR: Unable to get free space")
        poap_log_handle.close()
        abort_cleanup_exit()

    poap_log("INFO: free space is %s kB"  % freespace )

    if required_space > freespace:
        poap_log("ERR : Not enough space to copy the config, kickstart image and system image, aborting!")
        abort_cleanup_exit()


# figure out config filename to download based on serial-number
def set_config_file_src_serial_number (): 
    global config_file_src
    match=re.search("^(.*)\.cfg",config_file_src,re.MULTILINE)
    if match: config_file_src = "%s%s.cfg" % (match.group(1), serial_number)
    poap_log("INFO: Selected config filename (serial-nb) : %s" % config_file_src)


# figure out config filename to download based on cdp neighbor info
# sample output:
#   switch# show cdp neig
#   Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge
#                     S - Switch, H - Host, I - IGMP, r - Repeater,
#                     V - VoIP-Phone, D - Remotely-Managed-Device,
#                     s - Supports-STP-Dispute, M - Two-port Mac Relay
#
#   Device ID              Local Intrfce   Hldtme  Capability  Platform      Port ID
#   Switch                 mgmt0           148     S I         WS-C2960G-24T Gig0/2
#   switch(Nexus-Switch)   Eth1/1          150     R S I s     Nexus-Switch  Eth2/1
#   switch(Nexus-Switch)   Eth1/2          150     R S I s     Nexus-Switch  Eth2/2
# in xml:
#   <ROW_cdp_neighbor_brief_info>
#    <ifindex>83886080</ifindex>
#    <device_id>Switch</device_id>
#    <intf_id>mgmt0</intf_id>
#    <ttl>137</ttl>
#    <capability>switch</capability>
#    <capability>IGMP_cnd_filtering</capability>
#    <platform_id>cisco WS-C2960G-24TC-L</platform_id>
#    <port_id>GigabitEthernet0/4</port_id>
#   </ROW_cdp_neighbor_brief_info>

def set_config_file_src_location():
    global config_file_src
    cmd = "show cdp neighbors interface %s" % cdp_interface
    poap_log("CLI: %s" % cmd)
    try: r = run_cli(cmd);
    except: 
        poap_log("ERR: cant get neighbor info on %s", cdp_interface)
        exit(-1)

    lines=r.split("\n")

    try:
        idx = [i for i, line in enumerate(lines) if re.search('^.*Device-ID.*$', line)]
        ix=idx[0]+1
        line=lines[ix]
        words=line.split()
        # Check if there is a wrap due to long output string, which breaks one
        # line output into multiple lines
        while len(words)<6:
            ix=ix+1
            if ix<len(lines):
                line=line+' '+lines[ix]
                words=line.split()
            else:
                poap_log("ERR: 'show cdp neigbhor' output wraps. Incomplete merge: %s." % line)
                raise Exception("Invalid")
        switchName=words[0]
        intfName = words[len(words)-1]
    except:
        poap_log("ERR: unexpected 'show cdp neigbhor' output: %s" % r)
        exit(-1)
    switchName = switchName.split("(")[0]
    neighbor = "%s_%s" % (switchName, intfName)
    neighbor = string.replace(neighbor, "/", "_")
    match=re.search("^(.*)\.cfg",config_file_src,re.MULTILINE)
    if match: config_file_src = "%s_%s.cfg" % (match.group(1), neighbor)
    poap_log("INFO: Selected config filename (cdp-neighbor) : %s" % config_file_src)

# set complete name of config_file_src based on serial-number/interface (add extension)

if config_file_type == "location": 
    #set source config file based on location
    set_config_file_src_location()

elif config_file_type == "serial_number": 
    #set source config file based on switch's serial number
    set_config_file_src_serial_number()


# finaly do it

verify_freespace()
get_kickstart_image()
get_system_image()
verify_images()
get_config(config_file_type, serial_number_retry)

# prevent someone from sending a signal while we install the config
signal.signal(signal.SIGTERM, sig_handler_no_exit)
install_it()

poap_log_close()
exit(0)