#!/usr/bin/python
# -*- coding: utf-8 -*-

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

"""
=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 MAGIC MARKERS

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

=head1 VERSION

0.0.1

=head1 BUGS

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

=head1 AUTHOR

Johann Schmitz <johann@j-schmitz.net>

=head1 LICENSE

GPLv2

=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("^(?:|.*\/)snmp_([^_]+)_juniper$", sys.argv[0])
	host = match.group(1)
	request = match.group(2)
	match = re.search("^([^:]+):(\d+)$", host)
	if match is not None:
		host = match.group(1)
		port = match.group(2)
except:
	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)
#			ignoreNonIncreasingOids=True) # only available with pysnmp >= 4.2.4 (?)

		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

				# TODO: Find a better way to get the routing engines in a cluster
				if str(value).endswith(' Routing Engine'):
					devices[str(name)[len(jnxOperatingTable):]] = re.sub("[^\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.iteritems()]),
			'cpu': dict([(name, self.get_one(jnxOperatingCPU, suffix)) for suffix, name in devs.iteritems()]),
			'buffer': dict([(name, self.get_one(jnxOperatingBuffer, suffix)) for suffix, name in devs.iteritems()]),
		}

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

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

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

			for suffix, node in devices.iteritems():
				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.iteritems():
			print "multigraph juniper_%s" % pre
			for node, value in values.iteritems():
				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)
		sys.exit(1)
	
	if "config" in sys.argv[1:]:
		c.print_config()
	else:
		c.execute()
