nagios style last system update check for yum, dnf and apt

check_lastupdate.py

#!/usr/bin/env python

from __future__ import print_function
from datetime import timedelta
from datetime import datetime
import os
import re
import sys


def normalize_cmdline(cmdline):
    norm_cmdline = cmdline.split()
    for opt in list(norm_cmdline):
        if opt.startswith('-') or opt.isnumeric():
            norm_cmdline.remove(opt)
    return ' '.join(norm_cmdline)


NAG_OK = 0
NAG_WARNING = 1
NAG_CRITICAL = 2
NAG_UNKNOWN = 3

# cli arguments
crit_days = 31 if (len(sys.argv) < 2) else int(sys.argv[1])

if len(sys.argv) < 3:
    warn_days = (float(crit_days) / 4.0) * 3
else:
    warn_days = int(sys.argv[2])

crit_dt = datetime.now() - timedelta(days=crit_days)
warn_dt = datetime.now() - timedelta(days=warn_days)

last_dt = None

apt_log_path = os.getenv('APT_LOG_PATH', '/var/log/apt')

if os.path.exists(apt_log_path):
    # test
    import gzip
    import glob

    os.chdir(apt_log_path)
    found = False
    for histfile in sorted(glob.glob("history.log*"), key=os.path.getmtime, reverse=True):
        file = gzip.open(histfile, 'r') if histfile.endswith('.gz') else open(histfile, 'rb')
        for line in file:
            if line.startswith('Start-Date: '):
                found = False
            elif not found and re.match(r'Commandline: apt(-get)?( -y)? (dist-)?upgrade( -y)?$', line):
                found = True
            elif found and line.startswith('End-Date: '):
                last_dt = datetime.strptime(line, 'End-Date: %Y-%m-%d  %H:%M:%S\n')
        file.close()

        if last_dt is not None:
            break

elif os.path.exists('/var/lib/dnf'):
    import dnf
    pm = dnf.Base()

    for old in pm.history.old():
        if old.cmdline is not None:
            cmdline = normalize_cmdline(old.cmdline)
            if re.match(r'(system-upgrade )?(upgrade|update)$', cmdline) and len(old.error()) == 0:
                if old.end_timestamp is None:
                    last_dt = datetime.fromtimestamp(old.beg_timestamp)
                else:
                    last_dt = datetime.fromtimestamp(old.end_timestamp)
                break
elif os.path.exists('/var/lib/yum'):
    import yum
    pm = yum.YumBase()
    pm.preconf.debuglevel = 0
    pm.preconf.errorlevel = 0

    for old in pm.history.old():
        if old.cmdline is not None:
            cmdline = normalize_cmdline(old.cmdline)
            if re.match(r'(upgrade|update)$', cmdline) and len(old.errors) == 0:
                if old.end_timestamp is None:
                    last_dt = datetime.fromtimestamp(old.beg_timestamp)
                else:
                    last_dt = datetime.fromtimestamp(old.end_timestamp)
                break
else:
    print('unsupported os')
    raise SystemExit(NAG_UNKNOWN)

if last_dt is not None:
    print(last_dt)
    if last_dt < crit_dt:
        raise SystemExit(NAG_CRITICAL)
    elif last_dt < warn_dt:
        raise SystemExit(NAG_WARNING)
    else:
        raise SystemExit(NAG_OK)

print('not found')
raise SystemExit(NAG_UNKNOWN)