hostwatcher.py

#!/usr/bin/python

# Ping hosts and receive message if host doesn't answer
# A message will be sent only once per day and host during continuous downtime
#
# #example /etc/hostwatcher.conf:
# [main]
# # messenger should take the fail message as its first argument
# messenger = "/usr/local/sbin/telegrambot.py"
#
# [hosts]
# ping = [ "google.com", "facebook.com" ]
# ping6 = [ "ipv6.google.com", "facebook.com" ]
# http = [ "www.google.com" ]

import os
import json
import ConfigParser
import time

# Init config
config = ConfigParser.RawConfigParser()   
configFile = "/etc/hostwatcher.conf"
config.read(configFile)
failmessage = "does not answer" 

host_types = config.items( "hosts" )
for ping, hosts in host_types:
    for host in json.loads(hosts):
      # Try ping 2 times, break if host answers
      for i in range(2):
        print("{0} {1} try {2}".format(ping, host, i+1))
        # test http/https
        if ping[:4] == "http":
          response =  os.system("nc -z -w2 " + host + " " + ping)   
        # test ping     
        else:
          response = os.system(ping + " -c 1 -w 2 " + host + " > /dev/null 2>&1")
        
        statusfile = "/tmp/hostwatcher-nonresponsive-"+host
      
        # host doesn't answer on first try
        if response != 0 and i == 0:
          # wait seconds before retry
          time.sleep(10)
        # host doesn't answer on second try
        elif response != 0:
          message = "{0} {1} {2}.".format(host, failmessage, ping)
          print("-"+message)
          # if nonresponsive-status file does not exists yet, create it and send message
          if not os.path.isfile(statusfile):
            os.mknod(statusfile)
            os.system('{0} "(hostwatcher) {1}"'.format(config.get('main', 'messenger'), message))
          # if nonresponsive-status older than 24h, delete it to get new message
          elif time.time()-os.stat(statusfile).st_ctime > 86400:
            os.remove(statusfile)

        # Host answers and nonresponsive-status file exists 
        elif os.path.isfile(statusfile):
          os.remove(statusfile)
          os.system('{0} "(hostwatcher) {1} answers {2} again!"'.format(config.get('main', 'messenger'), host, ping))
          print "-{0} answers {1} again!".format(host, ping)
          break
        # Host answers 
        else:
          print "-{0} answers".format(host)
          break