src/logalert.py

   1 #!/usr/bin/env python3
   2
   3 import argparse
   4 import logging
   5 import os
   6 import signal
   7 import time
   8
   9 import misc
  10
  11 LINES_TO_KEEP = 10
  12 ALERT_INTERVAL = 86400
  13
  14 def handleInterrupt(sig, frame):
  15     global stop
  16     if os.getpid() == mainPid:
  17         logging.info( "Got stop signal." )
  18         stop = True
  19
  20 mainPid = os.getpid()
  21 signal.signal(signal.SIGINT, handleInterrupt)
  22
  23 stop = False
  24
  25 parser = argparse.ArgumentParser(description='Alert on excessive number of error log lines.')
  26 parser.add_argument('logfile', type=str, help='logfile to be watched')
  27 parser.add_argument('handler', type=str,
  28                     help='alert will be delivered to standard input of handler')
  29 parser.add_argument('-s', '--interval-size', type=int, default=600, dest='interval_size',
  30                     help='sample interval size in seconds (default: 600)')
  31 parser.add_argument('-n', '--num-intervals', type=int, default=6, dest='num_intervals',
  32                     help='number of intervals to keep in history (default: 6)')
  33 parser.add_argument('-l', '--log-level', type=str, default='INFO', dest='log_lvl',
  34                     choices=['DEBUG', 'INFO', 'WARNING'], help='select log level')
  35
  36 args = parser.parse_args()
  37
  38 logging.basicConfig(format='[%(asctime)s] %(levelname)s: %(message)s',
  39                     level=logging.getLevelName(args.log_lvl),
  40                     datefmt='%m/%d/%Y %H:%M:%S')
  41
  42 num_intervals = (args.num_intervals + 1)
  43 intervals = [False] * num_intervals
  44 lines = []
  45 last_time_slot = 0
  46 interval_ptr = 0
  47 error_state = False
  48 last_alert_time = 0
  49
  50 for line in misc.follow_file(args.logfile):
  51     time_now = time.time()
  52     time_slot = int(time_now) // args.interval_size
  53     time_slot_diff = time_slot - last_time_slot
  54     last_time_slot = time_slot
  55
  56     interval_ptr = (interval_ptr + time_slot_diff) % num_intervals
  57     for i in range(0, min(num_intervals, time_slot_diff)):
  58         intervals[(interval_ptr + i ) % num_intervals] = False
  59
  60     if line:
  61         intervals[interval_ptr] = True
  62         lines.append(line)
  63         if len(lines) > LINES_TO_KEEP:
  64             lines.pop(0)
  65
  66     logging.debug( misc.print_list(intervals, interval_ptr) )
  67
  68     intervals_error_state = True
  69     for i in range(1, num_intervals):
  70         if not intervals[(interval_ptr + i) % num_intervals]:
  71             intervals_error_state = False
  72             break
  73
  74     if intervals_error_state:
  75         if not error_state or time_now - last_alert_time > ALERT_INTERVAL:
  76             last_alert_time = time_now
  77             misc.feed_handler( args.handler,
  78                                misc.create_msg("Log Alert",
  79                                                "&#9760;",
  80                                                args.logfile,
  81                                                "Number of errors exceeded!",
  82                                                lines) )
  83         if not error_state:
  84             logging.warning("Entering error state!")
  85             error_state = True
  86
  87     else:
  88         if error_state:
  89             logging.info("Leaving error state.")
  90             error_state = False
  91
  92     if stop:
  93         break