modules/roles/files/mirror_health/mirror-health

   1 #! /usr/bin/python3
   2
   3 import os
   4 import requests
   5 import time
   6 import calendar
   7 import logging
   8 import subprocess
   9 from email.utils import parsedate
  10 logging.basicConfig(level=logging.INFO)
  11
  12 HOSTS = os.environ['MIRROR_CHECK_HOSTS'].split()
  13 OUTPUT_DIR = "/run/dsa-mirror-health-{}".format(os.environ['MIRROR_CHECK_SERVICE'])
  14 HEALTH_FILE = os.path.join(OUTPUT_DIR, "health")
  15 URL = os.environ['MIRROR_CHECK_URL']
  16 INTERVAL = int(os.environ.get('MIRROR_CHECK_INTERVAL', '60'))
  17
  18 latest_ts = 0
  19
  20 def retrieve_from_host(host, url):
  21     proxies = {
  22         'http': 'http://{}:80'.format(host),
  23         'https': 'http://{}:443'.format(host),
  24     }
  25     return requests.get(url, timeout=5, proxies=proxies, allow_redirects=False)
  26
  27 def last_modified(response):
  28     lm = 0
  29     if response.status_code == 200 and response.headers.get('last-modified'):
  30         lm = calendar.timegm(parsedate(response.headers['last-modified']))
  31     return lm
  32
  33 def check_shutdown():
  34     if subprocess.call(['dsa-is-shutdown-scheduled']) == 0:
  35         logging.info("considering myself unhealthy, shutdown scheduled")
  36         return False
  37     return True
  38
  39 def check_uptodate():
  40     global latest_ts
  41     for host in HOSTS:
  42         try:
  43             lm = last_modified(retrieve_from_host(host, URL))
  44             logging.debug("lm for host %s: %s", host, lm)
  45             latest_ts = max(latest_ts, lm)
  46         except (requests.exceptions.ProxyError, requests.exceptions.ReadTimeout):
  47             pass
  48     local_lm = last_modified(retrieve_from_host('localhost', URL))
  49     logging.debug("lm for localhost: %s", local_lm)
  50     if local_lm < latest_ts:
  51         logging.info("considering myself unhealthy my ts=%s latest_ts=%s", local_lm, latest_ts)
  52         return False
  53     return True
  54
  55 while True:
  56     start = time.time()
  57     if check_shutdown() and check_uptodate():
  58         logging.info("considering myself healthy")
  59         open(HEALTH_FILE, 'w').write("OK")
  60     else:
  61         try:
  62             os.remove(HEALTH_FILE)
  63         except OSError:
  64             pass
  65     sleep_time = start + INTERVAL - time.time()
  66     logging.debug("sleeping for %d seconds", sleep_time)
  67     time.sleep(sleep_time)