Script for monitoring internet

check_internet.py

import datetime
import time
import urllib2

def log(s, ts=None):
  ts = datetime.datetime.now()
  print ts.strftime("%H:%M:%S ") + s

def main():
  last_state_change = time.time()
  last_state = None
  while 1:
    start = time.time()
    try:
      s = urllib2.urlopen("https://www.google.com", timeout=5)
      log("up", start)
      state = "up"
    except urllib2.URLError:
      state = "down"
      log("error", start)

    if last_state != state:
      time_since = (start - last_state_change ) / 60
      msg = "state changed from {0!s} to {1!s} after {2!s} minutes".format(last_state, state, time_since)
      log(msg, start)

      last_state = state
      last_state_change = start
  
    time.sleep(max(0.001,  15 - (time.time() - start)))

main()