monitoring-scripts/check_minecraft

151 lines
6.6 KiB
Python
Executable File

#!/usr/bin/env python2
# coding=utf8
from datetime import datetime, timedelta
import sys, string, socket, time, argparse
# Exit statuses recognized by Nagios.
STATE_OK = 0
STATE_WARNING = 1
STATE_CRITICAL = 2
STATE_UNKNOWN = 3
# Output formatting string.
OUTPUT_OK = "MINECRAFT OK: {0} - {1} bytes in {2:.3} second response time|time={2}s;{3};{4};0.0;{5}"
OUTPUT_WARNING = "MINECRAFT WARNING: {0} - {1} bytes in {2:.3} second response time|time={2}s;{3};{4};0.0;{5}"
OUTPUT_CRITICAL = "MINECRAFT CRITICAL: {0} - {1} bytes in {2:.3} second response time|time={2}s;{3};{4};0.0;{5}"
OUTPUT_EXCEPTION = "MINECRAFT CRITICAL: {0}"
OUTPUT_UNKNOWN = "MINECRAFT UNKNOWN: Invalid arguments"
# Minecraft packet ID:s, delimiters and encoding.
MC_SERVER_LIST_PING = "\xfe"
MC_DISCONNECT = "\xff"
MC_DELIMITER = u"\xa7"
MC_ENCODING = "utf-16be"
def log(start, message):
print("{0}: {1}".format(datetime.now() - start, message))
def get_server_info(host, port, num_checks, timeout, verbose):
start_time = datetime.now()
total_delta = timedelta()
byte_count = len(MC_SERVER_LIST_PING) * num_checks
# Contact the server multiple times to get a stable average response time.
for i in range(0, num_checks):
if (verbose): iteration = "Iteration {0}/{1}: ".format(i + 1, num_checks)
# Save start time and connect to server.
if (verbose): log(start_time, "{0}Connecting to {1} on port {2}.".format(iteration, host, port))
net_start_time = datetime.now()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(timeout)
s.connect((host, port))
# Send Minecraft Server List Ping packet.
if (verbose): log(start_time, "{0}Sending Server List Ping.".format(iteration))
s.send(MC_SERVER_LIST_PING)
# Receive answer from server. The largest answer returned by the server that also works with the Minecraft client
# seems to be around 520 bytes (259 unicode character at 2 bytes each plus one start byte and one length byte).
if (verbose): log(start_time, "{0}Receiving data...".format(iteration))
data = s.recv(550)
data_len = len(data)
byte_count += data_len
if (verbose): log(start_time, "{0}Received {1} bytes".format(iteration, data_len))
s.close()
# Check if returned data seems valid. If not, throw AssertionError exception.
if (verbose):
if (data[0] == MC_DISCONNECT):
log(start_time, "Returned data seems valid.")
else:
log(start_time, "Returned data is invalid. First byte is {0:#x}.".format(ord(data[0])))
assert data[0] == MC_DISCONNECT
# Save response time for later average calculation.
delta = datetime.now() - net_start_time
total_delta += delta
time.sleep(0.1)
# Calculate the average response time in seconds
total_response = total_delta.seconds + total_delta.microseconds / 1000000.0
average_response = total_response / num_checks
# Decode and split returned skipping the first two bytes.
info = data[3:].decode(MC_ENCODING).split(MC_DELIMITER)
motd = info[:]
del motd[-1] # removing max_players
del motd[-1] # removing players
motd = ''.join(motd).replace("\n","") # removing newlines
return {'motd': motd,
'players': int(info[-2]),
'max_players': int(info[-1]),
'byte_count': byte_count,
'response_time': average_response}
def main():
parser = argparse.ArgumentParser(description="This plugin will try to connect to a Minecraft server.");
parser.add_argument('-H', '--hostname', dest='hostname', metavar='ADDRESS', required=True, help="host name or IP address")
parser.add_argument('-p', '--port', dest='port', type=int, default=25565, metavar='INTEGER', help="port number (default: 25565)")
parser.add_argument('-n', '--number-of-checks', dest='num_checks', type=int, default=5, metavar='INTEGER', help="number of checks to get stable average response time (default: 5)")
parser.add_argument('-m', '--motd', dest='motd', default='A Minecraft Server', metavar='STRING', help="expected motd in server response (default: A Minecraft Server)")
parser.add_argument('-f', '--warn-on-full', dest='full', action='store_true', help="generate warning if server is full")
parser.add_argument('-w', '--warning', dest='warning', type=float, default=0.0, metavar='DOUBLE', help="response time to result in warning status (seconds)")
parser.add_argument('-c', '--critical', dest='critical', type=float, default=0.0, metavar='DOUBLE', help="response time to result in critical status (seconds)")
parser.add_argument('-t', '--timeout', dest='timeout', type=float, default=10.0, metavar='DOUBLE', help="seconds before connection times out (default: 10)")
parser.add_argument('-v', '--verbose', dest='verbose', action='store_true', help="show details for command-line debugging (Nagios may truncate output)")
# Parse the arguments. If it failes, exit overriding exit code.
try:
args = parser.parse_args()
except SystemExit:
print(OUTPUT_UNKNOWN)
sys.exit(STATE_UNKNOWN)
try:
info = get_server_info(args.hostname, args.port, args.num_checks, args.timeout, args.verbose)
if string.find(info['motd'], args.motd) > -1:
# Check if response time is above critical level.
if args.critical and info['response_time'] > args.critical:
print(OUTPUT_CRITICAL.format("{0} second response time".format(info['response_time']), info['byte_count'], info['response_time'], args.warning, args.critical, args.timeout))
sys.exit(STATE_CRITICAL)
# Check if response time is above warning level.
if args.warning and info['response_time'] > args.warning:
print(OUTPUT_WARNING.format("{0} second response time".format(info['response_time']), info['byte_count'], info['response_time'], args.warning, args.critical, args.timeout))
sys.exit(STATE_WARNING)
# Check if server is full.
if args.full and info['players'] == info['max_players']:
print(OUTPUT_WARNING.format("Server full! {0} players online".format(info['players']), info['byte_count'], info['response_time'], args.warning, args.critical, args.timeout))
sys.exit(STATE_WARNING)
print(OUTPUT_OK.format("{0}/{1} players online".format(info['players'], info['max_players']), info['byte_count'], info['response_time'], args.warning, args.critical, args.timeout))
sys.exit(STATE_OK)
else:
print(OUTPUT_WARNING.format("Unexpected MOTD, {0}".format(info['motd']), info['byte_count'], info['response_time'], args.warning, args.critical, args.timeout))
sys.exit(STATE_WARNING)
except socket.error as msg:
print(OUTPUT_EXCEPTION.format(msg))
sys.exit(STATE_CRITICAL)
except AssertionError:
print(OUTPUT_EXCEPTION.format("Invalid data returned by server"))
sys.exit(STATE_CRITICAL)
except UnicodeDecodeError:
print(OUTPUT_EXCEPTION.format("Unable to decode server response"))
sys.exit(STATE_CRITICAL)
if __name__ == "__main__":
main()