Munin contributed plugins

# #!@@PYTHON@@

# -*- python -*-

"""

=head1 NAME

fail2ban_ - Wildcard plugin to monitor fail2ban blacklists

=head1 ABOUT

Requires Python 2.7

Requires fail2ban 0.9.2

=head1 AUTHOR

Copyright (c) 2015 Lee Clemens

Inspired by fail2ban plugin written by Stig Sandbeck Mathisen

=head1 CONFIGURATION

fail2ban-client needs to be run as root.

Add the following to your @@CONFDIR@@/munin-node:

  [fail2ban_*]

    user root

=head1 LICENSE

GNU GPLv2 or any later version

=begin comment

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or (at

your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

General Public License for more details

You should have received a copy of the GNU General Public License along

with this program; if not, write to the Free Software Foundation, Inc.,

51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

=end comment

=head1 BUGS

Transient values (particularly ASNs) come and go...

Better error handling (Popen), logging

Optimize loops and parsing in __get_jail_status() and parse_fail2ban_status()

Cymru ASNs aren't displayed in numerical order (internal name has alpha-prefix)

Use JSON status once fail2ban exposes JSON status data

=head1 MAGIC MARKERS

 #%# family=auto

 #%# capabilities=autoconf suggest

=cut

"""

from collections import Counter

from os import path, stat, access, X_OK, environ

from subprocess import Popen, PIPE

from time import time

import re

import sys

PLUGIN_BASE = "fail2ban_"

CACHE_DIR = environ['MUNIN_PLUGSTATE']

CACHE_MAX_AGE = 120

STATUS_FLAVORS_FIELDS = {

    "basic": ["jail"],

    "cymru": ["asn", "country", "rir"]

}

def __parse_plugin_name():

    if path.basename(__file__).count("_") == 1:

        return path.basename(__file__)[len(PLUGIN_BASE):], ""

    else:

        return (path.basename(__file__)[len(PLUGIN_BASE):].split("_")[0],

                path.basename(__file__)[len(PLUGIN_BASE):].split("_")[1])

def __get_jails_cache_file():

    return "%s/%s.state" % (CACHE_DIR, path.basename(__file__))

def __get_jail_status_cache_file(jail_name):

    return "%s/%s__%s.state" % (CACHE_DIR, path.basename(__file__), jail_name)

def __parse_jail_names(jails_data):

    """

    Parse the jails returned by `fail2ban-client status`:

    Status

    |- Number of jail:	3

    `- Jail list:	apache-badbots, dovecot, sshd

    """

    jails = []

    for line in jails_data.splitlines()[1:]:

        if line.startswith("`- Jail list:"):

            return [jail.strip(" ,\t") for jail in

                    line.split(":", 1)[1].split(" ")]

    return jails

def __get_jail_names():

    """

    Read jails from cache or execute `fail2ban-client status`

     and pass stdout to __parse_jail_names

    """

    cache_filename = __get_jails_cache_file()

    try:

        mtime = stat(cache_filename).st_mtime

    except OSError:

        mtime = 0

    if time() - mtime > CACHE_MAX_AGE:

        p = Popen(["fail2ban-client", "status"], shell=False, stdout=PIPE)

        jails_data = p.communicate()[0]

        with open(cache_filename, 'w') as f:

            f.write(jails_data)

    else:

        with open(cache_filename, 'r') as f:

            jails_data = f.read()

    return __parse_jail_names(jails_data)

def autoconf():

    """

    Attempt to find fail2ban-client in path (using `which`) and ping the client

    """

    p_which = Popen(["which", "fail2ban-client"], shell=False, stdout=PIPE,

                    stderr=PIPE)

    stdout, stderr = p_which.communicate()

    if len(stdout) > 0:

        client_path = stdout.strip()

        if access(client_path, X_OK):

            p_ping = Popen([client_path, "ping"], shell=False)

            p_ping.communicate()

            if p_ping.returncode == 0:

                print("yes")

            else:

                print("no (fail2ban-server does not respond to ping)")

        else:

            print("no (fail2ban-client is not executable)")

    else:

        import os

        print("no (fail2ban-client not found in path: %s)" %

              os.environ["PATH"])

def suggest():

    """

    Iterate all defined flavors (source of data) and fields (graph to display)

    """

    # Just use basic for autoconf/suggest

    flavor = "basic"

    for field in STATUS_FLAVORS_FIELDS[flavor]:

        print("%s_%s" % (flavor, field if len(flavor) > 0 else flavor))

def __get_jail_status(jail, flavor):

    """

    Return cache or execute `fail2ban-client status <jail> <flavor>`

     and save to cache and return

    """

    cache_filename = __get_jail_status_cache_file(jail)

    try:

        mtime = stat(cache_filename).st_mtime

    except OSError:

        mtime = 0

    if time() - mtime > CACHE_MAX_AGE:

        p = Popen(["fail2ban-client", "status", jail, flavor], shell=False,

                  stdout=PIPE)

        jail_status_data = p.communicate()[0]

        with open(cache_filename, 'w') as f:

            f.write(jail_status_data)

    else:

        with open(cache_filename, 'r') as f:

            jail_status_data = f.read()

    return jail_status_data

def __normalize(name):

    name = re.sub("[^a-z0-9A-Z]", "_", name)

    return name

def __count_groups(value_str):

    """

    Helper method to count unique values in the space-delimited value_str

    """

    return Counter([key for key in value_str.split(" ") if key])

def config(flavor, field):

    """

    Print config data (e.g. munin-run config), including possible labels

     by parsing real status data

    """

    print("graph_title fail2ban %s %s" % (flavor, field))

    print("graph_args --base 1000 -l 0")

    print("graph_vlabel Hosts banned")

    print("graph_category security")

    print("graph_info"

          " Number of hosts banned using status flavor %s and field %s" %

          (flavor, field))

    print("graph_total total")

    munin_fields, field_labels, values = parse_fail2ban_status(flavor, field)

    for munin_field in munin_fields:

        print("%s.label %s" % (munin_field, field_labels[munin_field]))

def run(flavor, field):

    """

    Parse the status data and print all values for a given flavor and field

    """

    munin_fields, field_labels, values = parse_fail2ban_status(flavor, field)

    for munin_field in munin_fields:

        print("%s.value %s" % (munin_field, values[munin_field]))

def parse_fail2ban_status(flavor, field):

    """

    Shared method to parse jail status output and determine field names

     and aggregate counts

    """

    field_labels = dict()

    values = dict()

    for jail in __get_jail_names():

        jail_status = __get_jail_status(jail, flavor)

        for line in jail_status.splitlines()[1:]:

            if flavor == "basic":

                if field == "jail":

                    if line.startswith("   |- Currently banned:"):

                        internal_name = __normalize(jail)

                        field_labels[internal_name] = jail

                        values[internal_name] = line.split(":", 1)[1].strip()

                else:

                    raise Exception(

                        "Undefined field %s for flavor %s for jail %s" %

                        (field, flavor, jail))

            elif flavor == "cymru":

                # Determine which line of output we care about

                if field == "asn":

                    search_string = "   |- Banned ASN list:"

                elif field == "country":

                    search_string = "   |- Banned Country list:"

                elif field == "rir":

                    search_string = "   `- Banned RIR list:"

                else:

                    raise Exception(

                        "Undefined field %s for flavor %s for jail %s" %

                        (field, flavor, jail))

                if line.startswith(search_string):

                    prefix = "%s_%s" % (flavor, field)

                    # Now process/aggregate the counts

                    counts_dict = __count_groups(line.split(":", 1)[1].strip())

                    for key in counts_dict:

                        internal_name = "%s_%s" % (prefix, __normalize(key))

                        if internal_name in field_labels:

                            values[internal_name] += counts_dict[key]

                        else:

                            field_labels[internal_name] = key

                            values[internal_name] = counts_dict[key]

            else:

                raise Exception("Undefined flavor: %s for jail %s" %

                                (flavor, jail))

    return sorted(field_labels.keys()), field_labels, values

if __name__ == "__main__":

    if len(sys.argv) > 1:

        command = sys.argv[1]

    else:

        command = ""

    if command == "autoconf":

        autoconf()

    elif command == "suggest":

        suggest()

    elif command == 'config':

        flavor_, field_ = __parse_plugin_name()

        config(flavor_, field_)

    else:

        flavor_, field_ = __parse_plugin_name()

        run(flavor_, field_)