python.d/isc_dhcdp.chart.py

   1 # -*- coding: utf-8 -*-
   2 # Description: isc dhcpd lease netdata python.d module
   3 # Author: l2isbad
   4
   5 from base import SimpleService
   6 from re import compile, search
   7 from time import mktime, strptime, gmtime
   8 try:
   9     from ipaddress import IPv4Address as ipaddress
  10     from ipaddress import ip_network
  11     have_ipaddress = True
  12 except ImportError:
  13     have_ipaddress = False
  14
  15 priority = 60000
  16 retries = 60
  17 update_every = 60
  18
  19 class Service(SimpleService):
  20     def __init__(self, configuration=None, name=None):
  21         SimpleService.__init__(self, configuration=configuration, name=name)
  22         self.leases_path = self.configuration.get('leases_path', '/var/lib/dhcp/dhcpd.leases')
  23         self.pools = self.configuration.get('pools')
  24
  25         # Will work only with 'default' db-time-format (weekday year/month/day hour:minute:second)
  26         # TODO: update the regex to parse correctly 'local' db-time-format
  27         # (epoch <seconds-since-epoch>; # <day-name> <month-name> <day-number> <hours>:<minutes>:<seconds> <year>)
  28         # Also only ipv4 supported
  29         self.regex = compile(r'(\d+(?:\.\d+){3}).*?((?<=ends )[0-9].*?(?=;))')
  30
  31     def check(self):
  32         if not self._get_raw_data():
  33             self.error('Make sure leases_path is correct and dhcpd.leases is readable by netdata')
  34             return False
  35         elif not have_ipaddress:
  36             self.error('No ipaddress module. Please install (py2-ipaddress in case of python2)')
  37             return False
  38         else:
  39             try:
  40                 self.pools = self.pools.split()
  41                 if not [ip_network(pool) for pool in self.pools]:
  42                     self.error('Pools list is empty')
  43                     return False
  44             except (ValueError, IndexError, AttributeError, SyntaxError):
  45                 self.error('Pools configurations is incorrect')
  46                 return False
  47
  48             # Creating dynamic charts
  49             self.order = ['utilization']
  50             self.definitions = {'utilization': {'options': [None, 'Pools utilization', 'used %', 'Utulization', 'isc_dhcpd.util', 'line'], 'lines': []} }
  51             for pool in self.pools:
  52                 self.definitions['utilization']['lines'].append([''.join(['ut_', pool]), pool, 'absolute'])
  53                 self.order.append(''.join(['leases_', pool]))
  54                 self.definitions[''.join(['leases_', pool])] = \
  55                     {'options': [None, 'Active leases', 'leases', 'Leases', 'isc_dhcpd.lease', 'area'],
  56                      'lines': [[''.join(['le_', pool]), pool, 'absolute']]}
  57
  58             self.info('Plugin was started succesfully')
  59             return True
  60
  61     def _get_raw_data(self):
  62         """
  63         Open log file
  64         :return: str
  65         """
  66         try:
  67             with open(self.leases_path, 'rt') as leases:
  68                 result = leases.read()
  69         except Exception:
  70             return None
  71         else:
  72             return result
  73
  74     def _get_data(self):
  75         """
  76         Parse dhcpd.leases file.
  77         """
  78         raw_leases = self._get_raw_data()
  79         all_leases = dict(self.regex.findall(' '.join(raw_leases.split())))
  80
  81         if  not all_leases:
  82             self.error('Cant parse leases file correctly')
  83             return None
  84
  85         # Result: [active binding, active binding....]. (Expire time (ends date;) - current time > 0)
  86         active_leases = [k for k, v in all_leases.items() if is_bind_active(all_leases[k])]
  87
  88         # Result: {pool: number of active bindings in pool, ...}
  89         pools_count = {pool: len([lease for lease in active_leases if is_address_in(lease, pool)]) for pool in self.pools}
  90
  91         # Result: {pool: number of host ip addresses in pool, }
  92         pools_max = {pool: (2 ** (32 - int(pool.split('/')[1])) - 2) for pool in self.pools}
  93
  94         # Result: {pool: % utilization, ....} (percent)
  95         pools_util = {pool:int(round(float(pools_count[pool]) / pools_max[pool] * 100, 0)) for pool in self.pools}
  96
  97         # Bulding dicts to send to netdata
  98         final_count = {''.join(['le_', k]): v for k, v in pools_count.items()}
  99         final_util = {''.join(['ut_', k]): v for k, v in pools_util.items()}
 100
 101         final_count.update(final_util)
 102
 103         return final_count
 104
 105 def is_bind_active(binding):
 106     return mktime(strptime(binding, '%w %Y/%m/%d %H:%M:%S')) - mktime(gmtime()) > 0
 107
 108 def is_address_in(address, pool):
 109     return ipaddress(address) in ip_network(pool)