server-checks.py

#!/usr/bin/python3

# monitor a group of websites and email alerts

# cron task:
#
# */5 * * * * t=$(mktemp); if ! python3 /home/user/server-checks.py >$t; then mail email@example.com -s "Web check $(date)" <$t; fi; rm $t
# https://ipsec.pl/ True 0.7856874465942383

# sample output (only if errors detected, otherwise stays silent)
#
# https://echelon.pl/ True 0.7726583480834961
# https://kabardians.com/ True 0.7841081619262695
# https://webcookies.org/ True 2.0685818195343018
# https://passphrase.today/ True 0.6283636093139648
# [0.6228809356689453, 0.6283636093139648, 8.63703966140747]
# https://cspbuilder.info/static/#/main/ True 0.5091941356658936
# http://evilsource.org/ True 0.3158442974090576
# http://carmichael.industries True 0.3121650218963623
# http://krawczyk.industries True 0.3126814365386963
# http://volkoff.industries True 0.31519412994384766
# http://webcookies.info True 0.317718505859375

import requests
import time
import statistics
import sys
from requests.exceptions import Timeout, ConnectionError

SERVERS = [
        { "url": "https://ipsec.pl/", },
        { "url": "https://echelon.pl/", },
        { "url": "https://kabardians.com/", },
        { "url": "https://webcookies.org/", },
        { "url": "https://passphrase.today/", },
        { "url": "https://cspbuilder.info/static/#/main/", },
        { "url": "http://evilsource.org/", },
        { "url": "http://carmichael.industries", },
        { "url": "http://krawczyk.industries", "expect": 301 },
        { "url": "http://volkoff.industries", },
        { "url": "http://webcookies.info", "expect": 307 },
     ]

ret = 0

ALERT_TIMEOUT = 5.0 # seconds
GOOD_RESPONSE_TIME = 3.0 # seconds

for server in SERVERS:
    result_set = []
    time_set = []
    url = server["url"]

    for attempt in range(3):
        t0 = time.time()
        try:
            r = requests.get(url, timeout=ALERT_TIMEOUT, allow_redirects=False)
        except (ConnectionError, Timeout) as e:
            print(url, e)
            break
        t1 = time.time()
        result_set.append(r) 
        time_set.append(t1-t0)

    if len(result_set):
        ok_codes = [ requests.codes.ok ]
        if "expect" in server:
            ok_codes.append(server["expect"])
        all_ok = all(list(map(lambda x: x.status_code in ok_codes, result_set)))
        all_fast = all(list(map(lambda x: x < GOOD_RESPONSE_TIME, time_set)))
        print(url, all_ok, statistics.median(time_set))
        if not all_ok:
            print('\t', result_set)
            ret = 1
        if not all_fast:
            print('\t', time_set)
            ret = 1

sys.exit(ret)