osm_lcm/lcm_hc.py

   1 #!/usr/bin/python3
   2 # -*- coding: utf-8 -*-
   3
   4 ##
   5 # Copyright 2018 Telefonica S.A.
   6 #
   7 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   8 # not use this file except in compliance with the License. You may obtain
   9 # a copy of the License at
  10 #
  11 #         http://www.apache.org/licenses/LICENSE-2.0
  12 #
  13 # Unless required by applicable law or agreed to in writing, software
  14 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  15 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  16 # License for the specific language governing permissions and limitations
  17 # under the License.
  18 ##
  19
  20 from os import path
  21 from time import time, sleep
  22 from sys import stderr
  23
  24 """ This module is used for helth check. A file called time_last_ping is used
  25 This contains the last time where something is received from kafka
  26 """
  27
  28
  29 def health_check(health_check_file=None, ping_interval_pace=120):
  30     health_check_file = health_check_file or path.expanduser("~") + "/time_last_ping"
  31     retry = 2
  32     while retry:
  33         retry -= 1
  34         try:
  35             with open(health_check_file, "r") as f:
  36                 last_received_ping = f.read()
  37
  38             if time() - float(last_received_ping) < 2 * ping_interval_pace:  # allow one ping not received every two
  39                 exit(0)
  40         except Exception as e:
  41             print(e, file=stderr)
  42         if retry:
  43             sleep(6)
  44     exit(1)
  45
  46
  47 if __name__ == '__main__':
  48     health_check()