blob: 61921124ffb6be43a3cf4be3788dbabc0af8a193 [file] [log] [blame] [edit]
#!/usr/bin/python
"""
usage:
./dhcp_failed_machines.py /var/log/dhcp.log
You can also run it directly on the gzip'd logs.
This script basically expects to run from the dhcp machine, as it looks at
/etc/dhcp/dhcpd.conf to be able to do reverse DNS lookups. It also expects the
dhcp log to be copied to some local file.
If you're lucky, there might still be a copy of this script already on the dhcp
server at /tmp/looky.py.
"""
import gzip
import itertools
import pprint
import re
import sys
lookups = {}
with open('/etc/dhcp/dhcpd.conf', 'r') as f:
for line in f:
if line.startswith('#'):
continue
if line.split() and line.split()[0] == 'host':
hostconf = list(itertools.takewhile(lambda x: x.strip() != '}', f))
d = dict([h.strip().split()[-2:] for h in hostconf])
hostname = d['ddns-hostname'].replace('"', '').replace(';', '')
lookups[d['fixed-address'].replace(';', '')] = hostname
offers = {}
offenders = set()
restarts = []
rgx = re.compile(
r'(?P<command>[A-Z]+) (?:from|on|for) (?P<host>\d+.\d+.\d+.\d+)')
server_restart_str = 'Internet Systems Consortium'
def open_file(f):
if f.endswith('.gz'):
return gzip.open(f, 'r')
else:
return open(f, 'r')
with open_file(sys.argv[1]) as f:
for line in f:
if server_restart_str in line:
restarts.append(line)
continue
m = rgx.search(line)
if m:
command = m.group('command')
host = m.group('host')
if command == 'DHCPOFFER':
offers[host] = offers.get(host, 0) + 1
if offers[host] > 2:
offenders.add(host)
if command == 'DHCPREQUEST':
offers[host] = 0
if restarts:
print 'DHCP restarts:\n %s' % ''.join(restarts)
def lookup(h):
return lookups.get(h, h)
hosts = sorted([lookup(h) for h in offenders])
if len(sys.argv) == 2:
pprint.pprint(hosts)
else:
warning = int(sys.argv[2])
critical = int(sys.argv[3])
if len(offenders) > critical:
print ('DHCP Critical, number of duts with DHCP failure is %d: %s' %
(len(hosts), ', '.join(hosts)))
sys.exit(2)
elif len(offenders) > warning:
print ('DHCP Warning, number of duts with DHCP failure is %d: %s' %
(len(hosts), ', '.join(hosts)))
sys.exit(1)
else:
print ('DHCP OK, number of duts with DHCP failure is %d: %s' %
(len(hosts), ', '.join(hosts)))
sys.exit(0)