check_status

#!/usr/bin/env python3
"""
Check the age of a status page. Can be used as monitoring check command.

No exceptions are catched. If anything fails (i.e. during http request),
exit code 1 will be returned which is interpreted as warning by icinga.

There is no timezone-awareness (yet). If your monitoring server has a
differeny timezone than the server serving the status page, your setup is
not compatible with this version of the script.
"""

import re
import sys

from argparse import ArgumentParser, Namespace
from datetime import datetime
from requests import get


def main():
    """Main routine."""
    parser = ArgumentParser(description='Simple status check script.')
    parser.add_argument(
        'url', type=str, help='URL of status page to check')
    parser.add_argument(
        '-r', '--regexp', type=str, default=r'<p>Effective: ([^<]+)',
        help='Regexp to match the effective date in page.')
    parser.add_argument(
        '-f', '--date-format', type=str, default='%d.%m.%Y %H:%M',
        help='Format used for date.')
    parser.add_argument(
        '-w', '--warning-age', type=int, default=300,
        help='Warning age (in seconds).')
    parser.add_argument(
        '-c', '--critical-age', type=int, default=900,
        help='Critical age (in seconds).')

    arguments = parser.parse_args()
    check_status_page(arguments)


def check_status_page(arguments: Namespace):
    """Check status of page at url."""
    status_page = get(arguments.url).text
    effective_date = re.search(arguments.regexp, status_page)
    if not effective_date:
        print('Effective date not found on status page.')
        sys.exit(2)
    effective_date = effective_date.group(1)
    effective_date = datetime.strptime(effective_date, arguments.date_format)
    now = datetime.now()
    age = now - effective_date
    print('Last update: {} ago'.format(age))
    age = age.total_seconds()

    if age >= arguments.critical_age:
        sys.exit(2)
    elif age >= arguments.warning_age:
        sys.exit(1)


if __name__ == '__main__':
    main()