Munin contributed plugins

#!/usr/bin/python

#

# Plugin to monitor fail2ban blacklists.

# Parses iptables output. Must be run as a user that may do such. Probably root.

#

# Requires: python, probably 2.3 or so :)

# 

# Written by Lasse Karstensen <lasse.karstensen@gmail.com> September 2007.

# Parameters understood:

# 	config   (required)

# 	autoconf (optional)

#

#%# family=auto

#%# capabilities=autoconf

libdir="/usr/share/fail2ban"

iptablesbin="/sbin/iptables"

import sys, os, ConfigParser

def get_fail2ban_checks(configfile="/etc/fail2ban.conf"):

    confReader = ConfigParser.ConfigParser()

    confReader.read(configfile)

    res = []

    for section in confReader.sections():

        # basic configuration, not essential for us so we skip it.

        if section in ["MAIL"]:

            continue

        if confReader.has_option(section, "enabled"):

	    val = confReader.get(section, "enabled")

	    if val.lower() == "true":

	        res.append(section)

    return res

def list_iptables(chain):

    global iptablesbin

    cmd = "%s -n -L fail2ban-%s" % (iptablesbin, chain)

    num = 0

    for line in os.popen(cmd):

        line = line.strip()

	if line.split()[0] == "DROP":

	    num = num + 1

    return num

def print_config():

    # noisy

    print 'graph_title Fail2ban blacklist'

    print 'graph_info This graph shows the number of host blocked by fail2ban.'

    print 'graph_category network'

    print 'graph_vlabel Count'

    print 'graph_args --base 1000 -l 0'

    print 'graph_total total'

    for checkname in get_fail2ban_checks():

        checkname_sane = checkname_sanitize(checkname)

        print '%s.label Rules in chain %s' % (checkname_sane, checkname_sane)

        print '%s.min 0' % checkname_sane

def checkname_sanitize(name):

    new = ""

    from string import digits, letters

    for char in name:

        if char not in letters+digits:

	    new += "_"

        else:

	    new += char

    return new

def main():

   if len(sys.argv) > 1 and sys.argv[1] == "autoconf":

       if os.path.isdir(libdir):

           print "yes"

	   sys.exit(0)

       else: 

           print "no"

           sys.exit(1)

   sys.path.append(libdir)

   if len(sys.argv) > 1 and sys.argv[1] == "config":

       print_config()

       sys.exit(0)

   for checkname in get_fail2ban_checks():

       num = list_iptables(checkname)

       print "%s.value %s" % (checkname_sanitize(checkname), num)

if __name__ == "__main__": 

    main()