OpenVPN ping plugin for Nagios

check_openvpn.py

#!/usr/bin/env python
# OpenVPN plugin for Nagios

from optparse import OptionParser
import socket
from datetime import datetime

def main():
	senddata= "\x38\x01\x00\x00\x00\x00\x00\x00\x00"

	usage = 'usage: %prog -H HOST [options]'
	parser = OptionParser(usage=usage)
	parser.add_option('-H', '--host', dest='host',
		help='host to check')
	parser.add_option('-p', '--port', dest='port', type='int',
		default=1194, help='port to check')
	parser.add_option('-t', '--tcp', dest='use_tcp', action='store_true',
		default=False, help='use TCP instead of UDP')
	parser.add_option('-w', '--timeout', dest='timeout', type='int',
		default=5, help='set the timeout')
	parser.add_option('-v', dest='verbose', action='store_true')
	(options, args) = parser.parse_args()
	
	if not options.host:
		parser.error('provide a --host/-H')
		exit(3) # unknown
	
	host = options.host
	port = options.port
	proto = (socket.SOCK_STREAM, 'tcp') if options.use_tcp \
		else (socket.SOCK_DGRAM, 'udp')
	
	if options.verbose:
		print "checking %s:%d %s"%(host, port, proto[1])

	sock = socket.socket(socket.AF_INET, proto[0])
	status = 0
	try:
		sock.settimeout(options.timeout)
		ts = datetime.now()
		sock.connect((host, port))
		sock.send(senddata)
		reply = sock.recv(100)
		te = datetime.now()
		if options.verbose:
			hreply = ''.join(['%02x'%ord(byte) for byte in reply])
			print 'received(hex): %s'%(hreply)
		td = te - ts
		print 'ok %.3fms'%(td.total_seconds()*1000)
		
		status = 0 # ok
	except socket.gaierror, e:
		print 'error: '+e.args[1]
		status = 2 # critical
	except:
		print 'server not responding'
		status = 2 # critical
	sock.close()
	exit(status)

if __name__ == "__main__":
	main()