downtime_scheduler

#!/usr/bin/env python

""" this program allows you to schedule downtime for a single hosts or batches
of servers specified in a batch list

format of batchfile is:

name_of_batch:
    name-of-nagios-server:
        - nagios-hosts-to-schedule-downtime-for
        - another-nagios-host-on-this-nagios

    another_nagios-server:
        - nagios-host-on-this-server

when scheduling downtime for a single host not in a batch
the downtime for that particular host is sent to all Nagios servers

"""
from argparse import ArgumentParser
from datetime import datetime
from datetime import timedelta
import requests
import yaml
import sys

# disable SSL warnings
requests.packages.urllib3.disable_warnings()

# nagios credentials
nagios_user = "nagiosusername"
nagios_pwd = "nagiospassword"

# nagios server / servers
nagios_servers = dict.fromkeys({"nagios1", "nagios2", "nagios3"})

def_downtime_single = 20
def_downtime_batch = 60

batch_file = "./batch.yml"
msg = "Patching"
downtime_type = {"services_downtime": 86, "host_downtime": 55}


def get_date_object(date):
    """ parses a string date and time and returns a date object """
    date, time = date.split()
    year, month, day, minute, hour, seconds = [
        int(x) for x in date.split("-") + time.split(":")
    ]
    return datetime(year, month, day, minute, hour)


def get_start_stop_time(minutes, date=datetime.utcnow()):
    """ given minutes to pass and a start timestamp
    returns start time and end time """

    start_t = date.strftime("%Y-%m-%d %H:%M:%S")
    stop_t = (date + timedelta(minutes=minutes)).strftime("%Y-%m-%d %H:%M:%S")
    return start_t, stop_t


def get_nagios_hosts_from_file():
    try:
        with open(batch_file) as f:
            return yaml.safe_load(f)
    except IOError:
        print(" IO Error , does batch file in path exist")
        sys.exit(1)


def send_command(nagios_server, nagios_host, message, start_t, stop_t, dtime):
    """ Send commands to a Nagios server using CGI """
    nagios_url = "https://" + nagios_server + "/nagios/cgi-bin/cmd.cgi"
    post_data = {
        "cmd_typ": downtime_type[dtime],
        "cmd_mod": 2,
        "host": nagios_host,
        "com_data": message,
        "trigger": 0,
        "start_time": start_t,
        "end_time": stop_t,
        "fixed": 1,
        "hours": 2,
        "minutes": 0,
        "btnSubmit": "Commit",
    }

    r = requests.post(
        nagios_url, auth=(nagios_user, nagios_pwd), verify=False, data=post_data
    )
    if args.verbose:
        print(r)


def single_or_multiple_hosts(hosts, start_t, stop_t, message):
    hosts = hosts.split(",")
    if len(hosts) == 1:
        host_schedule_downtime(args.single, start_t, stop_t, args.message)
    else:
        for host in hosts:
            host_schedule_downtime(host, start_t, stop_t, args.message)


def host_schedule_downtime(host, start_t, stop_t, message):
    """To skip specifying Nagios server for a single instance
    we send the downtime schedule to all Nagios servers :) """

    for key in nagios_servers.keys():
        nagios_servers[key] = [host]

    host_source = {"single": nagios_servers}

    bulk_schedule_downtime("single", host_source, start_t, stop_t, message)


def bulk_schedule_downtime(batch, hosts_source, start_t, stop_t, message):
    now = datetime.now().strftime("[%H:%M]")

    if not args.datetime:
        print("%s Scheduling %s minutes of downtime for:" % (now, args.minutes))
    else:
        print(
            "Scheduling %s minutes of downtime starting UTC %s for:"
            % (args.minutes, args.datetime)
        )

    for nagios_server, hosts in hosts_source[batch].items():
        for host in hosts:
            print("%s --> %s" % (host, nagios_server))
            send_command(nagios_server, host, message, start_t, stop_t, "host_downtime")
            send_command(
                nagios_server, host, message, start_t, stop_t, "services_downtime"
            )


def set_default_downtime_length():
    if args.batch:  # set longer default downtime for batches
        if args.minutes == 0:
            args.minutes = def_downtime_batch
    else:
        if args.minutes == 0:
            args.minutes = def_downtime_single


parser = ArgumentParser()
parser.add_argument(
    "-l",
    "--list",
    help="list batches",
    dest="list_batches",
    action="store_true",
    default=False,
)

parser.add_argument("-s", "--single", help="specify comma separated hosts")

parser.add_argument(
    "-b", "--batch", help="batch schedule", choices=get_nagios_hosts_from_file()
)

parser.add_argument(
    "-m",
    "--minutes",
    nargs="?",
    const=1,
    type=int,
    default=0,
    help="downtime in min. default "
    + str(def_downtime_single)
    + "/"
    + str(def_downtime_batch)
    + " for single/batch",
)

parser.add_argument(
    "-msg",
    "--message",
    nargs="?",
    const=1,
    default="scheduled downtime",
    help="custom downtime msg",
)

parser.add_argument(
    "-dt",
    "--datetime",
    help="start date time in \
                    UTC format: '1970-01-01 16:16:12'",
)

parser.add_argument(
    "-v",
    "--verbose",
    help="Verbose responses from Nagios",
    dest="verbose",
    action="store_true",
    default=False,
)
args = parser.parse_args()


def main():
    if args.datetime:
        if not args.minutes:
            if not args.batch:
                args.minutes = 20
            else:
                args.minutes = 60
        start_t, stop_t = get_start_stop_time(
            args.minutes, get_date_object(args.datetime)
        )
    else:
        set_default_downtime_length()
        start_t, stop_t = get_start_stop_time(args.minutes)

    if args.list_batches:
        print(
            yaml.dump(
                get_nagios_hosts_from_file(),
                allow_unicode=True,
                default_flow_style=False,
            )
        )
    elif args.batch:

        host_source = get_nagios_hosts_from_file()
        bulk_schedule_downtime(args.batch, host_source, start_t, stop_t, args.message)

    elif args.single:
        single_or_multiple_hosts(args.single, start_t, stop_t, args.message)

    else:
        if len(sys.argv) == 1:
            parser.print_help()


main()