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 HEALTH_CHECK_URL = os.environ['MIRROR_CHECK_HEALTH_URL']
  17 INTERVAL = int(os.environ.get('MIRROR_CHECK_INTERVAL', '60'))
  18
  19 def retrieve_from_host(host, url):
  20     proxies = {
  21         'http': 'http://{}:80'.format(host),
  22         'https': 'http://{}:443'.format(host),
  23     }
  24     return requests.get(url, timeout=5, proxies=proxies, allow_redirects=False)
  25
  26 def last_modified(response):
  27     lm = 0
  28     if response.status_code == 200 and response.headers.get('last-modified'):
  29         lm = calendar.timegm(parsedate(response.headers['last-modified']))
  30     return lm
  31
  32 def healthy(response):
  33     if response.status_code == 200:
  34         return True
  35     return False
  36
  37 def check_shutdown():
  38     if subprocess.call(['dsa-is-shutdown-scheduled']) == 0:
  39         logging.info("considering myself unhealthy, shutdown scheduled")
  40         return False
  41     return True
  42
  43 def check_uptodate():
  44     latest_ts = 0
  45     for host in HOSTS:
  46         try:
  47             lm = last_modified(retrieve_from_host(host, URL))
  48             logging.debug("lm for host %s: %s", host, lm)
  49             if healthy(retrieve_from_host(host, HEALTH_CHECK_URL)):
  50                 latest_ts = max(latest_ts, lm)
  51         except (requests.exceptions.ProxyError, requests.exceptions.ReadTimeout, requests.exceptions.ConnectTimeout):
  52             pass
  53     try:
  54         local_lm = last_modified(retrieve_from_host('localhost', URL))
  55     except (requests.exceptions.ProxyError, requests.exceptions.ReadTimeout, requests.exceptions.ConnectTimeout):
  56         return False
  57     logging.debug("lm for localhost: %s", local_lm)
  58     if local_lm < latest_ts:
  59         logging.info("considering myself unhealthy my ts=%s latest_ts=%s", local_lm, latest_ts)
  60         return False
  61     return True
  62
  63 while True:
  64     start = time.time()
  65     if check_shutdown() and check_uptodate():
  66         logging.info("considering myself healthy")
  67         open(HEALTH_FILE, 'w').write("OK")
  68     else:
  69         try:
  70             os.remove(HEALTH_FILE)
  71         except OSError:
  72             pass
  73     sleep_time = start + INTERVAL - time.time()
  74     logging.debug("sleeping for %d seconds", sleep_time)
  75     time.sleep(sleep_time)