monitors an VPN connection and controls OSX Shimo.app in case of problems

shimo_vpn.py

#!/usr/bin/python
# OSX VPN monitor
#
# requires:
# - http://www.chungwasoft.com/shimo/
# - http://growl.info/
# - http://appscript.sourceforge.net/

import sys
import socket
import appscript
import time

MONITOR_HOST = 'DESTINATION_IP'
VPN_PROFILE = 'test - mobile' # as named in Shimo perferences

growl = appscript.app('GrowlHelperApp')
growl.register(
    as_application='vpn check',
    all_notifications=['vpn down', 'vpn up'],
    default_notifications=['vpn down']
)

vpn = appscript.app('Shimo')

def growl_alert(msg):
    growl.notify(
        with_name='vpn down',
        title='VPN down',
        description=msg,
        application_name = 'vpn check'
    )

if __name__ == '__main__':
    print '\rvpn check initalizing..',

    while True:
        # up to 3 attempts to conenct to server with 5 sec timeout 
        # otherwise reconnect vpn connection and alert via growl

        error_count = 3
        while error_count >= 1:
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.settimeout(5)
            try:
                s.connect((MONITOR_HOST, 53))
            except:
                print '\rVPN DOWN - %s' % time.ctime()
                error_count -= 1
            else:
                print '\rVPN OK - %s' % time.ctime(),
                error_count = 3
                time.sleep(5)

            s.close()
            sys.stdout.flush()

        # ensure that overal internet is still up to avoid loop with
        # 3 connection attempts
        test_count = 3
        test_timeout = 5
        while test_count >= 1:
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.settimeout(test_timeout)
            try:
                s.connect((socket.gethostbyname('www.google.com'), 80))
            except:
                print '\rNo Connection - %s' % time.ctime(),
                sys.stdout.flush()
                test_count = 3
            else:
                time.sleep(1)
                test_count -= 1

        # only called if all connect attempts failed
        print 'reconnect VPN with 10 sec delay'
        sys.stdout.flush()


        # re connect vpn with 10 sec delay
        vpn.disconnect()
        time.sleep(10)
        vpn.connect(
            with_profile=VPN_PROFILE
        )

        growl_alert('VPN re-connected %s - %s' % (VPN_PROFILE, time.ctime()))

        # delay before monitoring starts after connection
        time.sleep(30)