checks/k8s_replicas

   1 #!/usr/bin/python
   2 # -*- encoding: utf-8; py-indent-offset: 4 -*-
   3 # +------------------------------------------------------------------+
   4 # |             ____ _               _        __  __ _  __           |
   5 # |            / ___| |__   ___  ___| | __   |  \/  | |/ /           |
   6 # |           | |   | '_ \ / _ \/ __| |/ /   | |\/| | ' /            |
   7 # |           | |___| | | |  __/ (__|   <    | |  | | . \            |
   8 # |            \____|_| |_|\___|\___|_|\_\___|_|  |_|_|\_\           |
   9 # |                                                                  |
  10 # | Copyright Mathias Kettner 2018             mk@mathias-kettner.de |
  11 # +------------------------------------------------------------------+
  12 #
  13 # This file is part of Check_MK.
  14 # The official homepage is at http://mathias-kettner.de/check_mk.
  15 #
  16 # check_mk is free software;  you can redistribute it and/or modify it
  17 # under the  terms of the  GNU General Public License  as published by
  18 # the Free Software Foundation in version 2.  check_mk is  distributed
  19 # in the hope that it will be useful, but WITHOUT ANY WARRANTY;  with-
  20 # out even the implied warranty of  MERCHANTABILITY  or  FITNESS FOR A
  21 # PARTICULAR PURPOSE. See the  GNU General Public License for more de-
  22 # tails. You should have  received  a copy of the  GNU  General Public
  23 # License along with GNU Make; see the file  COPYING.  If  not,  write
  24 # to the Free Software Foundation, Inc., 51 Franklin St,  Fifth Floor,
  25 # Boston, MA 02110-1301 USA.
  26
  27
  28 def parse_k8s_surge(value, total):
  29     """
  30     Returns the upper level for replicas which is considered critical
  31     (hence the +1 in the return value). Values may be given as an
  32     absolute number or in percent.
  33     """
  34     if isinstance(value, int):
  35         return value + total + 1
  36     percentage = 1.0 + float(value.rstrip('%')) / 100.0
  37     return math.ceil(percentage * total) + 1
  38
  39
  40 def parse_k8s_unavailability(value, total):
  41     """
  42     Returns the lower level for replicas which is still considered ok.
  43     Values may be given as an absolute number or in percent.
  44     """
  45     if isinstance(value, int):
  46         return total - value
  47     percentage = 1.0 - float(value.rstrip('%')) / 100.0
  48     return math.floor(percentage * total)
  49
  50
  51 def inventory_k8s_replicas(parsed):
  52     if parsed['ready_replicas'] is not None and parsed['replicas'] is not None:
  53         return [(None, {})]
  54
  55
  56 def check_k8s_replicas(_no_item, params, parsed):
  57     ready, total = parsed['ready_replicas'], parsed['replicas']
  58     paused, strategy = parsed['paused'], parsed['strategy_type']
  59
  60     if paused or strategy == 'Recreate':
  61         crit, crit_lower = None, None
  62     elif strategy == 'RollingUpdate':
  63         crit = parse_k8s_surge(parsed['max_surge'], total)
  64         crit_lower = parse_k8s_unavailability(parsed['max_unavailable'], total)
  65     else:
  66         yield 3, "Unknown deployment strategy: %s" % strategy
  67         return
  68
  69     state = 0
  70     infotext = "Ready: %s/%s" % (ready, total)
  71     if paused:
  72         infotext += ' (paused)'
  73     if crit is not None and ready >= crit:
  74         state = 2
  75         infotext += " (crit at %d)" % crit
  76     if crit_lower is not None and ready < crit_lower:
  77         state = 2
  78         infotext += " (crit below %d)" % crit_lower
  79
  80     perfdata = [
  81         ('ready_replicas', ready, None, crit),
  82         ('total_replicas', total),
  83     ]
  84     yield state, infotext, perfdata
  85
  86     if strategy:
  87         strategy_infotext = "Strategy: %s" % parsed['strategy_type']
  88         if strategy == 'RollingUpdate':
  89             strategy_infotext += " (max unavailable: %s, max surge: %s)" % (
  90                 parsed['max_unavailable'],
  91                 parsed['max_surge'],
  92             )
  93         yield 0, strategy_infotext
  94
  95
  96 check_info['k8s_replicas'] = {
  97     'parse_function': parse_k8s,
  98     'inventory_function': inventory_k8s_replicas,
  99     'check_function': check_k8s_replicas,
 100     'service_description': 'Replicas',
 101     'has_perfdata': True,
 102     'includes': ['k8s.include'],
 103 }