nagios-http-json/check_http_json.py
2024-06-28 14:39:57 +02:00

761 lines
30 KiB
Python
Executable File

#!/usr/bin/env python3
import urllib.request, urllib.error, urllib.parse
import base64
import json
import argparse
import sys
import ssl
from urllib.error import HTTPError
from urllib.error import URLError
from datetime import datetime, timedelta, timezone
plugin_description = \
"""
Check HTTP JSON Nagios Plugin
Generic Nagios plugin which checks json values from a given endpoint against
argument specified rules and determines the status and performance data for
that service.
"""
OK_CODE = 0
WARNING_CODE = 1
CRITICAL_CODE = 2
UNKNOWN_CODE = 3
__version__ = '2.2.0'
__version_date__ = '2024-05-14'
class NagiosHelper:
"""
Help with Nagios specific status string formatting.
"""
message_prefixes = {OK_CODE: 'OK',
WARNING_CODE: 'WARNING',
CRITICAL_CODE: 'CRITICAL',
UNKNOWN_CODE: 'UNKNOWN'}
performance_data = ''
warning_message = ''
critical_message = ''
unknown_message = ''
def getMessage(self, message=''):
"""
Build a status-prefixed message with optional performance data
generated externally
"""
message += self.warning_message
message += self.critical_message
message += self.unknown_message
code = self.message_prefixes[self.getCode()]
output = "{code}: Status {code}. {message}".format(code=code, message=message.strip())
if self.performance_data:
output = "{code}: {perf_data} Status {code}. {message}|{perf_data}".format(
code=code,
message=message.strip(),
perf_data=self.performance_data)
return output.strip()
def getCode(self):
code = OK_CODE
if (self.warning_message != ''):
code = WARNING_CODE
if (self.critical_message != ''):
code = CRITICAL_CODE
if (self.unknown_message != ''):
code = UNKNOWN_CODE
return code
def append_message(self, code, msg):
if code > 2 or code < 0:
self.unknown_message += msg
if code == 1:
self.warning_message += msg
if code == 2:
self.critical_message += msg
def append_metrics(self, metrics):
(performance_data, warning_message, critical_message) = metrics
self.performance_data += performance_data
self.append_message(WARNING_CODE, warning_message)
self.append_message(CRITICAL_CODE, critical_message)
class JsonHelper:
"""
Perform simple comparison operations against values in a given
JSON dict
"""
def __init__(self, json_data, separator, value_separator):
self.data = json_data
self.separator = separator
self.value_separator = value_separator
self.arrayOpener = '('
self.arrayCloser = ')'
def getSubElement(self, key, data):
separatorIndex = key.find(self.separator)
partialKey = key[:separatorIndex]
remainingKey = key[separatorIndex + 1:]
if partialKey in data:
return self.get(remainingKey, data[partialKey])
return (None, 'not_found')
def getSubArrayElement(self, key, data):
subElemKey = key[:key.find(self.arrayOpener)]
index = int(key[key.find(self.arrayOpener) +
1:key.find(self.arrayCloser)])
remainingKey = key[key.find(self.arrayCloser + self.separator) + 2:]
if key.find(self.arrayCloser + self.separator) == -1:
remainingKey = key[key.find(self.arrayCloser) + 1:]
if subElemKey in data:
if index < len(data[subElemKey]):
return self.get(remainingKey, data[subElemKey][index])
else:
return (None, 'not_found')
if index >= len(data):
return (None, 'not_found')
else:
if not subElemKey:
return self.get(remainingKey, data[index])
else:
return (None, 'not_found')
def equals(self, key, value):
return self.exists(key) and \
str(self.get(key)) in value.split(self.value_separator)
def lte(self, key, value):
return self.exists(key) and float(self.get(key)) <= float(value)
def lt(self, key, value):
return self.exists(key) and float(self.get(key)) < float(value)
def gte(self, key, value):
return self.exists(key) and float(self.get(key)) >= float(value)
def gt(self, key, value):
return self.exists(key) and float(self.get(key)) > float(value)
def exists(self, key):
return (self.get(key) != (None, 'not_found'))
def get(self, key, temp_data=''):
"""
Can navigate nested json keys with a dot format
(Element.Key.NestedKey). Returns (None, 'not_found') if not found
"""
if temp_data != '':
data = temp_data
else:
data = self.data
if len(key) <= 0:
return data
if key.find(self.separator) != -1 and \
key.find(self.arrayOpener) != -1:
if key.find(self.separator) < key.find(self.arrayOpener):
return self.getSubElement(key, data)
else:
return self.getSubArrayElement(key, data)
else:
if key.find(self.separator) != -1:
return self.getSubElement(key, data)
else:
if key.find(self.arrayOpener) != -1:
return self.getSubArrayElement(key, data)
else:
if isinstance(data, dict) and key in data:
return data[key]
else:
return (None, 'not_found')
def expandKey(self, key, keys):
if '(*)' not in key:
keys.append(key)
return keys
subElemKey = ''
if key.find('(*)') > 0:
subElemKey = key[:key.find('(*)')-1]
remainingKey = key[key.find('(*)')+3:]
elemData = self.get(subElemKey)
if elemData == (None, 'not_found'):
keys.append(key)
return keys
if subElemKey != '':
subElemKey = subElemKey + '.'
for i in range(len(elemData)):
newKey = subElemKey + '(' + str(i) + ')' + remainingKey
newKeys = self.expandKey(newKey, [])
for j in newKeys:
keys.append(j)
return keys
def _getKeyAlias(original_key):
key = original_key
alias = original_key
if '>' in original_key:
keys = original_key.split('>')
if len(keys) == 2:
key, alias = keys
return key, alias
class JsonRuleProcessor:
"""
Perform checks and gather values from a JSON dict given rules
and metrics definitions
"""
def __init__(self, json_data, rules_args):
self.data = json_data
self.rules = rules_args
separator = '.'
value_separator = ':'
if self.rules.separator:
separator = self.rules.separator
if self.rules.value_separator:
value_separator = self.rules.value_separator
self.helper = JsonHelper(self.data, separator, value_separator)
debugPrint(rules_args.debug, "rules: %s" % rules_args)
debugPrint(rules_args.debug, "separator: %s" % separator)
debugPrint(rules_args.debug, "value_separator: %s" % value_separator)
self.metric_list = self.expandKeys(self.rules.metric_list)
self.key_threshold_warning = self.expandKeys(
self.rules.key_threshold_warning)
self.key_threshold_critical = self.expandKeys(
self.rules.key_threshold_critical)
self.key_value_list = self.expandKeys(self.rules.key_value_list)
self.key_value_list_not = self.expandKeys(
self.rules.key_value_list_not)
self.key_time_list = self.expandKeys(self.rules.key_time_list)
self.key_list = self.expandKeys(self.rules.key_list)
self.key_value_list_critical = self.expandKeys(
self.rules.key_value_list_critical)
self.key_value_list_not_critical = self.expandKeys(
self.rules.key_value_list_not_critical)
self.key_time_list_critical = self.expandKeys(self.rules.key_time_list_critical)
self.key_list_critical = self.expandKeys(self.rules.key_list_critical)
self.key_value_list_unknown = self.expandKeys(
self.rules.key_value_list_unknown)
def expandKeys(self, src):
if src is None:
return []
dest = []
for key in src:
newKeys = self.helper.expandKey(key, [])
for k in newKeys:
dest.append(k)
return dest
def checkExists(self, exists_list):
failure = ''
for k in exists_list:
key, alias = _getKeyAlias(k)
if (self.helper.exists(key) is False):
failure += " Key %s did not exist." % alias
return failure
def checkEquality(self, equality_list):
failure = ''
for kv in equality_list:
k, v = kv.split(',')
key, alias = _getKeyAlias(k)
if not self.helper.equals(key, v):
failure += " Key %s mismatch. %s != %s" % (alias, v,
self.helper.get(key))
return failure
def checkNonEquality(self, equality_list):
failure = ''
for kv in equality_list:
k, v = kv.split(',')
key, alias = _getKeyAlias(k)
if self.helper.equals(key, v):
failure += " Key %s match found. %s == %s" % (alias, v,
self.helper.get(key))
return failure
def checkThreshold(self, key, alias, r):
failure = ''
invert = False
start = 0
end = 'infinity'
if r.startswith('@'):
invert = True
r = r[1:]
vals = r.split(':')
if len(vals) == 1:
end = vals[0]
if len(vals) == 2:
start = vals[0]
if vals[1] != '':
end = vals[1]
if(start == '~'):
if (invert and self.helper.lte(key, end)):
failure += " Value (%s) for key %s was less than or equal to %s." % \
(self.helper.get(key), alias, end)
elif (not invert and self.helper.gt(key, end)):
failure += " Value (%s) for key %s was greater than %s." % \
(self.helper.get(key), alias, end)
elif(end == 'infinity'):
if (invert and self.helper.gte(key, start)):
failure += " Value (%s) for key %s was greater than or equal to %s." % \
(self.helper.get(key), alias, start)
elif (not invert and self.helper.lt(key, start)):
failure += " Value (%s) for key %s was less than %s." % \
(self.helper.get(key), alias, start)
else:
if (invert and self.helper.gte(key, start) and
self.helper.lte(key, end)):
failure += " Value (%s) for key %s was inside the range %s:%s." % \
(self.helper.get(key), alias, start, end)
elif (not invert and (self.helper.lt(key, start) or
self.helper.gt(key, end))):
failure += " Value (%s) for key %s was outside the range %s:%s." % \
(self.helper.get(key), alias, start, end)
return failure
def checkThresholds(self, threshold_list):
failure = ''
for threshold in threshold_list:
k, r = threshold.split(',')
key, alias = _getKeyAlias(k)
failure += self.checkThreshold(key, alias, r)
return failure
def checkTimestamp(self, key, alias, r):
failure = ''
invert = False
negative = False
if r.startswith('@'):
invert = True
r = r[1:]
if r.startswith('-'):
negative = True
r = r[1:]
duration = int(r[:-1])
unit = r[-1]
if unit == 's':
tiemduration = timedelta(seconds=duration)
elif unit == 'm':
tiemduration = timedelta(minutes=duration)
elif unit == 'h':
tiemduration = timedelta(hours=duration)
elif unit == 'd':
tiemduration = timedelta(days=duration)
else:
return " Value (%s) is not a vaild timeduration." % (r)
if not self.helper.exists(key):
return " Key (%s) for key %s not Exists." % \
(key, alias)
try:
timestamp = datetime.fromisoformat(self.helper.get(key))
except ValueError as ve:
return " Value (%s) for key %s is not a Date in ISO format. %s" % \
(self.helper.get(key), alias, ve)
now = datetime.now(timezone.utc)
if timestamp.tzinfo == None:
timestamp = timestamp.replace(tzinfo=timezone.utc)
age = now - timestamp
if not negative:
if age > tiemduration and not invert:
failure += " Value (%s) for key %s is older than now-%s%s." % \
(self.helper.get(key), alias, duration, unit)
if not age > tiemduration and invert:
failure += " Value (%s) for key %s is newer than now-%s%s." % \
(self.helper.get(key), alias, duration, unit)
else:
if age < -tiemduration and not invert:
failure += " Value (%s) for key %s is newer than now+%s%s." % \
(self.helper.get(key), alias, duration, unit)
if not age < -tiemduration and invert:
failure += " Value (%s) for key %s is older than now+%s%s.." % \
(self.helper.get(key), alias, duration, unit)
return failure
def checkTimestamps(self, threshold_list):
failure = ''
for threshold in threshold_list:
k, r = threshold.split(',')
key, alias = _getKeyAlias(k)
failure += self.checkTimestamp(key, alias, r)
return failure
def checkWarning(self):
failure = ''
if self.key_threshold_warning is not None:
failure += self.checkThresholds(self.key_threshold_warning)
if self.key_value_list is not None:
failure += self.checkEquality(self.key_value_list)
if self.key_value_list_not is not None:
failure += self.checkNonEquality(self.key_value_list_not)
if self.key_time_list is not None:
failure += self.checkTimestamps(self.key_time_list)
if self.key_list is not None:
failure += self.checkExists(self.key_list)
return failure
def checkCritical(self):
failure = ''
if not self.data:
failure = " Empty JSON data."
if self.key_threshold_critical is not None:
failure += self.checkThresholds(self.key_threshold_critical)
if self.key_value_list_critical is not None:
failure += self.checkEquality(self.key_value_list_critical)
if self.key_value_list_not_critical is not None:
failure += self.checkNonEquality(self.key_value_list_not_critical)
if self.key_time_list_critical is not None:
failure += self.checkTimestamps(self.key_time_list_critical)
if self.key_list_critical is not None:
failure += self.checkExists(self.key_list_critical)
return failure
def checkUnknown(self):
unknown = ''
if self.key_value_list_unknown is not None:
unknown += self.checkEquality(self.key_value_list_unknown)
return unknown
def checkMetrics(self):
"""
Return a Nagios specific performance metrics string given keys
and parameter definitions
"""
metrics = ''
warning = ''
critical = ''
if self.metric_list is not None:
for metric in self.metric_list:
key = metric
minimum = maximum = warn_range = crit_range = None
uom = ''
if ',' in metric:
vals = metric.split(',')
if len(vals) == 2:
key, uom = vals
if len(vals) == 4:
key, uom, warn_range, crit_range = vals
if len(vals) == 6:
key, uom, warn_range, crit_range, \
minimum, maximum = vals
key, alias = _getKeyAlias(key)
if self.helper.exists(key):
metrics += "'%s'=%s" % (alias, self.helper.get(key))
if uom:
metrics += uom
if warn_range is not None:
warning += self.checkThreshold(key, alias, warn_range)
metrics += ";%s" % warn_range
if crit_range is not None:
critical += self.checkThreshold(key, alias, crit_range)
metrics += ";%s" % crit_range
if minimum is not None:
critical += self.checkThreshold(key, alias, minimum +
':')
metrics += ";%s" % minimum
if maximum is not None:
critical += self.checkThreshold(key, alias, '~:' +
maximum)
metrics += ";%s" % maximum
metrics += ' '
return ("%s" % metrics, warning, critical)
def parseArgs(args):
"""
CLI argument definitions and parsing
"""
parser = argparse.ArgumentParser(
description=plugin_description + '\n\nVersion: %s (%s)'
%(__version__, __version_date__),
formatter_class=argparse.RawDescriptionHelpFormatter
)
parser.add_argument('-d', '--debug', action='store_true',
help='debug mode')
parser.add_argument('-v', '--verbose', action='count', default=0,
help='Verbose mode. Multiple -v options increase the verbosity')
parser.add_argument('-s', '--ssl', action='store_true',
help='use TLS to connect to remote host')
parser.add_argument('-H', '--host', dest='host',
required=not ('-V' in args or '--version' in args),
help='remote host to query')
parser.add_argument('-k', '--insecure', action='store_true',
help='do not check server SSL certificate')
parser.add_argument('-X', '--request', dest='method', default='GET', choices=['GET', 'POST'],
help='Specifies a custom request method to use when communicating with the HTTP server')
parser.add_argument('-V', '--version', action='store_true',
help='print version of this plugin')
parser.add_argument('--cacert',
dest='cacert', help='SSL CA certificate')
parser.add_argument('--cert',
dest='cert', help='SSL client certificate')
parser.add_argument('--key', dest='key',
help='SSL client key ( if not bundled into the cert )')
parser.add_argument('-P', '--port', dest='port', help='TCP port')
parser.add_argument('-p', '--path', dest='path', help='Path')
parser.add_argument('-t', '--timeout', type=int,
help='Connection timeout (seconds)')
parser.add_argument('--unreachable-state', type=int, default=3,
help='Exit with specified code if URL unreachable. Examples: 1 for Warning, 2 for Critical, 3 for Unknown (default: 3)')
parser.add_argument('-B', '--basic-auth', dest='auth',
help='Basic auth string "username:password"')
parser.add_argument('-D', '--data', dest='data',
help='The http payload to send as a POST')
parser.add_argument('-A', '--headers', dest='headers',
help='The http headers in JSON format.')
parser.add_argument('-f', '--field_separator', dest='separator',
help='''JSON Field separator, defaults to ".";
Select element in an array with "(" ")"''')
parser.add_argument('-F', '--value_separator', dest='value_separator',
help='''JSON Value separator, defaults to ":"''')
parser.add_argument('-w', '--warning', dest='key_threshold_warning',
nargs='*',
help='''Warning threshold for these values
(key1[>alias],WarnRange key2[>alias],WarnRange).
WarnRange is in the format [@]start:end, more
information at
nagios-plugins.org/doc/guidelines.html.''')
parser.add_argument('-c', '--critical', dest='key_threshold_critical',
nargs='*',
help='''Critical threshold for these values
(key1[>alias],CriticalRange key2[>alias],CriticalRange.
CriticalRange is in the format [@]start:end, more
information at
nagios-plugins.org/doc/guidelines.html.''')
parser.add_argument('-e', '--key_exists', dest='key_list', nargs='*',
help='''Checks existence of these keys to determine
status. Return warning if key is not present.''')
parser.add_argument('-E', '--key_exists_critical',
dest='key_list_critical',
nargs='*',
help='''Same as -e but return critical if key is
not present.''')
parser.add_argument('-q', '--key_equals', dest='key_value_list', nargs='*',
help='''Checks equality of these keys and values
(key[>alias],value key2,value2) to determine status.
Multiple key values can be delimited with colon
(key,value1:value2). Return warning if equality
check fails''')
parser.add_argument('-Q', '--key_equals_critical',
dest='key_value_list_critical', nargs='*',
help='''Same as -q but return critical if
equality check fails.''')
parser.add_argument('--key_time', dest='key_time_list', nargs='*',
help='''Checks a Timestamp of these keys and values
(key[>alias],value key2,value2) to determine status.
Multiple key values can be delimited with colon
(key,value1:value2). Return warning if the key is older
than the value (ex.: 30s,10m,2h,3d,...).
With at it return warning if the key is jounger
than the value (ex.: @30s,@10m,@2h,@3d,...).
With Minus you can shift the time in the future.''')
parser.add_argument('--key_time_critical',
dest='key_time_list_critical', nargs='*',
help='''Same as --key_time but return critical if
Timestamp age fails.''')
parser.add_argument('-u', '--key_equals_unknown',
dest='key_value_list_unknown', nargs='*',
help='''Same as -q but return unknown if
equality check fails.''')
parser.add_argument('-y', '--key_not_equals',
dest='key_value_list_not', nargs='*',
help='''Checks equality of these keys and values
(key[>alias],value key2,value2) to determine status.
Multiple key values can be delimited with colon
(key,value1:value2). Return warning if equality
check succeeds''')
parser.add_argument('-Y', '--key_not_equals_critical',
dest='key_value_list_not_critical', nargs='*',
help='''Same as -q but return critical if equality
check succeeds.''')
parser.add_argument('-m', '--key_metric', dest='metric_list', nargs='*',
help='''Gathers the values of these keys (key[>alias],
UnitOfMeasure,WarnRange,CriticalRange,Min,Max) for
Nagios performance data. More information about Range
format and units of measure for nagios can be found at
nagios-plugins.org/doc/guidelines.html
Additional formats for this parameter are:
(key[>alias]), (key[>alias],UnitOfMeasure),
(key[>alias],UnitOfMeasure,WarnRange,
CriticalRange).''')
return parser.parse_args(args)
def debugPrint(debug_flag, message):
"""
Print debug messages if -d is set.
"""
if not debug_flag:
return
print(message)
def verbosePrint(verbose_flag, when, message):
"""
Print verbose messages if -v is set.
Since -v can be used multiple times, the when parameter sets the required amount before printing
"""
if not verbose_flag:
return
if verbose_flag >= when:
print(message)
def prepare_context(args):
"""
Prepare TLS Context
"""
nagios = NagiosHelper()
context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
context.options |= ssl.OP_NO_SSLv2
context.options |= ssl.OP_NO_SSLv3
if args.insecure:
context.check_hostname = False
context.verify_mode = ssl.CERT_NONE
else:
context.verify_mode = ssl.CERT_OPTIONAL
context.load_default_certs()
if args.cacert:
try:
context.load_verify_locations(args.cacert)
except ssl.SSLError:
nagios.append_message(UNKNOWN_CODE, 'Error loading SSL CA cert "%s"!' % args.cacert)
if args.cert:
try:
context.load_cert_chain(args.cert, keyfile=args.key)
except ssl.SSLError:
if args.key:
nagios.append_message(UNKNOWN_CODE, 'Error loading SSL cert. Make sure key "%s" belongs to cert "%s"!' % (args.key, args.cert))
else:
nagios.append_message(UNKNOWN_CODE, 'Error loading SSL cert. Make sure "%s" contains the key as well!' % (args.cert))
if nagios.getCode() != OK_CODE:
print(nagios.getMessage())
sys.exit(nagios.getCode())
return context
def make_request(args, url, context):
"""
Performs the actual request to the given URL
"""
req = urllib.request.Request(url, method=args.method)
req.add_header("User-Agent", "check_http_json")
if args.auth:
authbytes = str(args.auth).encode()
base64str = base64.encodebytes(authbytes).decode().replace('\n', '')
req.add_header('Authorization', 'Basic %s' % base64str)
if args.headers:
headers = json.loads(args.headers)
debugPrint(args.debug, "Headers:\n %s" % headers)
for header in headers:
req.add_header(header, headers[header])
if args.timeout and args.data:
databytes = str(args.data).encode()
response = urllib.request.urlopen(req, timeout=args.timeout,
data=databytes, context=context)
elif args.timeout:
response = urllib.request.urlopen(req, timeout=args.timeout,
context=context)
elif args.data:
databytes = str(args.data).encode()
response = urllib.request.urlopen(req, data=databytes, context=context)
else:
# pylint: disable=consider-using-with
response = urllib.request.urlopen(req, context=context)
return response.read()
def main(cliargs):
"""
Main entrypoint for CLI
"""
args = parseArgs(cliargs)
nagios = NagiosHelper()
context = None
if args.version:
print('Version: %s - Date: %s' % (__version__, __version_date__))
sys.exit(0)
if args.ssl:
url = "https://%s" % args.host
context = prepare_context(args)
else:
url = "http://%s" % args.host
if args.port:
url += ":%s" % args.port
if args.path:
url += "/%s" % args.path
debugPrint(args.debug, "url: %s" % url)
json_data = ''
try:
json_data = make_request(args, url, context)
except HTTPError as e:
# Try to recover from HTTP Error, if there is JSON in the response
if "json" in e.info().get_content_subtype():
json_data = e.read()
else:
nagios.append_message(UNKNOWN_CODE, " Could not find JSON in HTTP body. HTTPError[%s], url:%s" % (str(e.code), url))
except URLError as e:
# Some users might prefer another exit code if the URL wasn't reached
exit_code = args.unreachable_state
nagios.append_message(exit_code, " URLError[%s], url:%s" % (str(e.reason), url))
# Since we don't got any data, we can simply exit
print(nagios.getMessage())
sys.exit(nagios.getCode())
try:
data = json.loads(json_data)
except ValueError as e:
nagios.append_message(UNKNOWN_CODE, " JSON Parser error: %s" % str(e))
else:
verbosePrint(args.verbose, 1, json.dumps(data, indent=2))
# Apply rules to returned JSON data
processor = JsonRuleProcessor(data, args)
nagios.append_message(WARNING_CODE, processor.checkWarning())
nagios.append_message(CRITICAL_CODE, processor.checkCritical())
nagios.append_metrics(processor.checkMetrics())
nagios.append_message(UNKNOWN_CODE, processor.checkUnknown())
# Print Nagios specific string and exit appropriately
print(nagios.getMessage())
sys.exit(nagios.getCode())
if __name__ == "__main__":
# Program entry point
main(sys.argv[1:])
#EOF