Nginx Status monitoring plugin script

check_nginx.py

#!/usr/bin/env python3


"""
Parse the Nginx Status output and return as monitoring plugin data.
"""


import nagiosplugin
from http.client import HTTPConnection
import re, argparse


class Nginx(nagiosplugin.Resource):
	def __init__(self, host='localhost', port=80, url='/nginx_status', timeout=5):
		self.host    = host
		self.port    = port
		self.url     = url
		self.timeout = timeout

	def probe(self):
		result = {}
		url = "/nginx_status"

		connection = HTTPConnection(self.host, self.port, timeout=self.timeout)
		connection.request("GET", self.url)
		response = connection.getresponse()
		data = response.read().decode("UTF-8")

		m1 = re.search(r'Active connections:\s+(?P<connections>\d+)', data)
		m2 = re.search(r'\s*(?P<accepted>\d+)\s+(?P<handled>\d+)\s+(?P<requests>\d+)', data)
		m3 = re.search(r'Reading:\s*(?P<reading>\d+)\s*Writing:\s*(?P<writing>\d+)\s*Waiting:\s*(?P<waiting>\d+)', data)

		if not m1 or not m2 or not m3:
			raise Exception('Unable to parse %s' % url)

		yield nagiosplugin.Metric('connections', int(m1.groupdict()['connections']), min=0, context='connections')

		_accepted = int(m2.groupdict()['accepted'])
		_handled  = int(m2.groupdict()['handled'])
		_requests = int(m2.groupdict()['requests'])
		yield nagiosplugin.Metric('accepted', _accepted, min=0, context='default')
		yield nagiosplugin.Metric('handled', _handled, min=0, context='default')
		yield nagiosplugin.Metric('requests', _requests, min=0, context='default')

		yield nagiosplugin.Metric('reading', int(m3.groupdict()['reading']), min=0, context='default')
		yield nagiosplugin.Metric('writing', int(m3.groupdict()['writing']), min=0, context='default')
		yield nagiosplugin.Metric('waiting', int(m3.groupdict()['waiting']), min=0, context='default')


def main():
	argp = argparse.ArgumentParser(description=__doc__, add_help=False)

	argp.add_argument('-h', '--host', default='localhost', help='')
	argp.add_argument('-p', '--port', default=80, help='')
	argp.add_argument('-u', '--url', default='/nginx_status', help='')

	argp.add_argument('-t', '--timeout', default=5, help='')

	argp.add_argument('-w', '--warning', metavar='WARN', default='', help='return warning if number of connections greater than WARN')
	argp.add_argument('-c', '--critical', metavar='CRIT', default='', help='return critical if number of connections is greater than CRIT')

	argp.add_argument('--help', action='help', help='show this help message and exit')

	args = argp.parse_args()

	check = nagiosplugin.Check(
		Nginx(args.host, args.port, args.url, args.timeout),
		nagiosplugin.ScalarContext('connections', args.warning, args.critical, fmt_metric='{value} connections')
	)
	check.main()


if __name__ == '__main__':
	main()