#!/usr/bin/env python3
"""
=head1 NAME

snmp__juniper - Health monitoring plugin for Juniper firewalls.

=head1 CONFIGURATION

Make sure your Juniper device is accessible via SNMP (e.g. via snmpwalk) and the munin-node
has been configured correctly.

=head1 VERSION

0.0.1

=head1 BUGS

Open a ticket at https://github.com/ercpe/contrib if you find one.

=head1 AUTHOR

Copyright (C) 2014 Johann Schmitz <johann@j-schmitz.net>


=head1 LICENSE

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; version 2 only

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 Library General Public License for more details.

You should have received a copy of the GNU Library General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

SPDX-License-Identifier: GPL-2.0-only


=head1 MAGIC MARKERS

    #%# family=snmpauto
    #%# capabilities=snmpconf

=cut
"""

import re
import sys
import os
import logging

from pysnmp.entity.rfc3413.oneliner import cmdgen

host = None
port = os.getenv('port', 161)
community = os.getenv('community', None)

debug = bool(os.getenv('MUNIN_DEBUG', os.getenv('DEBUG', 0)))

if debug:
    logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)-7s %(message)s')

try:
    match = re.search(r"^(?:|.*/)snmp_([^_]+)_juniper$", sys.argv[0])
    host = match.group(1)
    request = match.group(2)
    match = re.search(r"^([^:]+):(\d+)$", host)
    if match is not None:
        host = match.group(1)
        port = match.group(2)
except Exception:
    pass

jnxOperatingTable = '1.3.6.1.4.1.2636.3.1.13.1.5'

jnxOperatingTemp = '1.3.6.1.4.1.2636.3.1.13.1.7'
jnxOperatingCPU = '1.3.6.1.4.1.2636.3.1.13.1.8'
jnxOperatingBuffer = '1.3.6.1.4.1.2636.3.1.13.1.11'


class JunOSSnmpClient(object):
    def __init__(self, host, port, community):
        self.hostname = host
        self.transport = cmdgen.UdpTransportTarget((host, int(port)))
        self.auth = cmdgen.CommunityData('test-agent', community)
        self.gen = cmdgen.CommandGenerator()

    def get_devices(self):
        errorIndication, errorStatus, errorIndex, varBindTable = self.gen.bulkCmd(
            self.auth,
            self.transport,
            0, 20,
            jnxOperatingTable)
        # the following line is only available with pysnmp >= 4.2.4 (?)
        # ignoreNonIncreasingOids=True)

        if errorIndication:
            logging.error("SNMP bulkCmd for devices failed: %s, %s, %s"
                          % (errorIndication, errorStatus, errorIndex))
            return {}

        devices = {}
        for row in varBindTable:
            for name, value in row:
                if not str(name).startswith(jnxOperatingTable):
                    continue

                if 'Routing Engine' in str(value):
                    devices[str(name)[len(jnxOperatingTable):]] = re.sub(
                        r"[^\w]", '_', str(value).replace(' Routing Engine', ''))
        return devices

    def get_one(self, prefix_oid, suffix):
        oid = prefix_oid + suffix
        errorIndication, errorStatus, errorIndex, varBindTable = self.gen.getCmd(
            self.auth,
            self.transport,
            oid)

        if errorIndication:
            logging.error("SNMP getCmd for %s failed: %s, %s, %s"
                          % (oid, errorIndication, errorStatus, errorIndex))
            return None

        return int(varBindTable[0][1])

    def get_data(self):
        devs = self.get_devices()

        return {
            'temp': dict([(name, self.get_one(jnxOperatingTemp, suffix))
                          for suffix, name in devs.items()]),
            'cpu': dict([(name, self.get_one(jnxOperatingCPU, suffix))
                         for suffix, name in devs.items()]),
            'buffer': dict([(name, self.get_one(jnxOperatingBuffer, suffix))
                            for suffix, name in devs.items()]),
        }

    def print_config(self):
        devices = self.get_devices()

        data_def = [
            ('temp', self.hostname, 'System temperature', '--base 1000',
             'System temperature in C'),
            ('cpu', self.hostname, 'CPU usage', '--base 1000 -l 0 --upper-limit 100',
             'CPU usage in %'),
            ('buffer', self.hostname, 'Buffer usage', '--base 1000 -l 0 --upper-limit 100',
             'Buffer usage in %'),
        ]

        for datarow, hostname, title, args, vlabel in data_def:
            print("""multigraph juniper_{datarow}
host_name {hostname}
graph_title {title}
graph_vlabel {vlabel}
graph_args {args}
graph_category fw
graph_info {title}""".format(datarow=datarow, hostname=hostname, title=title, args=args,
                             vlabel=vlabel))

            for suffix, node in devices.items():
                ident = "%s_%s" % (datarow, node)
                print("""{label}.info {title} on {node}
{label}.label {node}
{label}.type GAUGE
{label}.min 0""".format(title=title, label=ident, node=node))

    def execute(self):
        data = self.get_data()

        for pre, values in data.items():
            print("multigraph juniper_%s" % pre)
            for node, value in values.items():
                print("%s_%s.value %s" % (pre, node, value))


c = JunOSSnmpClient(host, port, community)


if "snmpconf" in sys.argv[1:]:
    print("require 1.3.6.1.4.1.2636.3.1.13.1.5")
    sys.exit(0)
else:
    if not (host and port and community):
        print("# Bad configuration. Cannot run with Host=%s, port=%s and community=%s"
              % (host, port, community), file=sys.stderr)
        sys.exit(1)

    if "config" in sys.argv[1:]:
        c.print_config()
    else:
        c.execute()