#!/usr/bin/env python3
# check_last_dist_upgrade_via_ssh.py

import sys,re
from optparse import OptionParser
from time import time
from datetime import date
from subprocess import run, PIPE

parser = OptionParser()
parser.add_option("-H","--host-name",dest="host",help="host to send command to")
parser.add_option("-F","--configfile",dest="ssh_config_file",help="ssh config file to use")
parser.add_option("-i","--identitiy-file",dest="ssh_key_file",help="identity file to use")

# args is throwaway variable that captures left over arguments from sys.argv
options,args = parser.parse_args()
ssh_command = "ssh "

if options.ssh_config_file: ssh_command += "-F " + options.ssh_config_file + " "
if options.ssh_key_file: ssh_command += "-i " + options.ssh_key_file + " "
if options.host:
    ssh_command += options.host
else:
    print("Critical - Invalid Host")
    sys.exit(2)

ssh_command += " \'cat /var/log/apt/history.log\'"

start = time()
output = run(ssh_command, shell=True, stdout=PIPE).stdout.decode("utf-8").rstrip()
output_paragraphs = re.split('\n\s*\n',output)
block_with_last_dist_upgrade = ""

for block in output_paragraphs:
    if "dist-upgrade" in block:
        block_with_last_dist_upgrade = output_paragraphs.index(block)

if block_with_last_dist_upgrade == "":
    elapsed_time = (time() - start)
    print("no \"dist-upgrade\" in apt history log | elapsed_time=" + str(elapsed_time))
    sys.exit(3)

last_dist_upgrade_details = output_paragraphs[block_with_last_dist_upgrade].split()
upgrade_year,upgrade_month,upgrade_day = last_dist_upgrade_details[1].split('-')
upgrade_month = upgrade_month.lstrip('0')
upgrade_day = upgrade_day.lstrip('0')
time_since_upgrade = date.today() - date(int(upgrade_year), int(upgrade_month), int(upgrade_day))

if time_since_upgrade.days > 60:
    elapsed_time = (time() - start)
    print(str(time_since_upgrade.days) + " days since last upgrade | elapsed_time=" + str(elapsed_time))
    sys.exit(2)
elif time_since_upgrade.days > 30:
    elapsed_time = (time() - start)
    print(str(time_since_upgrade.days) + " days since last upgrade | elapsed_time=" + str(elapsed_time))
    sys.exit(1)
else:
    elapsed_time = (time() - start)
    print(str(time_since_upgrade.days) + " days since last upgrade | elapsed_time=" + str(elapsed_time))
    sys.exit(0)