config/build-nagios

   1 #!/usr/bin/ruby
   2
   3 # build nagios and nrpe config from a single master config file
   4
   5 # Copyright (c) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Peter Palfrader <peter@palfrader.org>
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining
   8 # a copy of this software and associated documentation files (the
   9 # "Software"), to deal in the Software without restriction, including
  10 # without limitation the rights to use, copy, modify, merge, publish,
  11 # distribute, sublicense, and/or sell copies of the Software, and to
  12 # permit persons to whom the Software is furnished to do so, subject to
  13 # the following conditions:
  14 #
  15 # The above copyright notice and this permission notice shall be
  16 # included in all copies or substantial portions of the Software.
  17 #
  18 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  22 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25
  26
  27 require "yaml"
  28
  29 ORG="dsa"
  30 SHORTORG="dsa"
  31 GENERATED_PREFIX="./generated/"
  32
  33 nagios_filename = {};
  34 %w(hosts hostgroups services dependencies hostextinfo serviceextinfo servicegroups).each{
  35         |x| nagios_filename[x] = GENERATED_PREFIX+"auto-#{x}.cfg"
  36 }
  37 nagios_filename['nrpe'] = GENERATED_PREFIX+"nrpe_#{ ORG }.cfg"
  38
  39
  40 MAX_CHECK_ATTEMPTS_DEFAULT=6
  41
  42 NRPE_CHECKNAME="#{ ORG }_check_nrpe"           # check that takes one argument:  service name to be checked
  43 NRPE_CHECKNAME_HOST="#{ ORG }_check_nrpe_host" # check that takes two arguments: relay host on which to run check, service name to be checked
  44
  45 HOST_TEMPLATE_NAME='generic-host'          # host templates that all our host definitions use
  46 SERVICE_TEMPLATE_NAME='generic-service'    # host templates that all our host definitions use
  47 HOST_ALIVE_CHECK='check-host-alive'        # host alive check if server is pingable
  48 NRPE_PROCESS_SERVICE='process - nrpe'      # nrpe checks will depend on this one
  49
  50
  51 def warn (msg)
  52         STDERR.puts msg
  53 end
  54 def set_if_unset(hash, key, value)
  55         hash[key] = value unless hash.has_key?(key)
  56 end
  57 def set_complain_if_set(hash, key, value, type, name)
  58         throw "#{type} definition '#{name}' has '#{key}' already defined" if hash.has_key?(key)
  59         hash[key] = value
  60 end
  61
  62 # Make an array out of something.  If there is nothing, create an empty array
  63 # if it is just a string, make a list with just that element, if it already is
  64 # an array keep it.
  65 def ensure_array(something)
  66         if (something == nil)
  67                 result = []
  68         elsif something.kind_of?(String)
  69                 result = [ something ]
  70         elsif something.kind_of?(Array)
  71                 result = something
  72         else
  73                 throw "Do now know how to make an array out of #{something}: " + something.to_yaml
  74         end
  75         return result
  76 end
  77
  78
  79 # This class keeps track of the checks done via NRPE and makes sure
  80 # each gets a unique name.
  81 #
  82 # Unforutunately NRPE limits check names to some 30 characters, so
  83 # we need to mangle service names near the end.
  84 class Nrpe
  85         def initialize
  86                 @checks = {}
  87         end
  88
  89         def make_name( name, check )
  90                 name = name.tr_s("^a-zA-Z", "_").gsub("process", "ps")
  91
  92                 result = "#{ SHORTORG }_" + name[0,19]
  93
  94                 hash = ''
  95                 skew = ''
  96                 while (@checks.has_key?(result + hash))
  97                         # hash it, so that we don't lose uniqeness by cutting it off
  98                         hash = (check+skew).crypt("$1$")
  99                         hash = hash[-5,5]  # 5 chars are enough
 100                         hash.tr!("/", "_")
 101                         skew += ' ' # change it a bit so the hash changes
 102                 end
 103                 result += hash
 104                 return result      # max of 32 or so chars
 105         end
 106
 107         def add( name, check )
 108                 if @checks.has_value? check
 109                         @checks.each_pair{ |key, value|
 110                                 return key if value == check
 111                         }
 112                 end
 113                 key = make_name(name, check)
 114                 @checks[ key ] = check
 115                 return key
 116         end
 117
 118         def checks
 119                 return @checks
 120         end
 121 end
 122 $nrpe = Nrpe.new()
 123
 124
 125 # Prints the keys and values of hash to a file
 126 # This is the function that prints the bodies of most our
 127 # host/service/etc definitions
 128 #
 129 # It skips over such keys as are listed in exclude_keys
 130 # and also skips private keys (those starting with an underscore)
 131 def print_block(fd, kind, hash, exclude_keys)
 132         fd.puts "define #{kind} {"
 133         hash.keys.sort.each{ |key|
 134                 next if key == '_extinfo'
 135                 next if key == '_hostgroups'
 136                 next if key == '_memberlist'
 137                 next if exclude_keys.include? key
 138                 fd.puts "       #{key}          #{hash[key]}"
 139         }
 140         fd.puts "}"
 141         fd.puts
 142 end
 143
 144 def merge_contacts(host, service)
 145         %w{contacts contact_groups}.each{ |k|
 146                 contacts = []
 147                 [host, service].each{ |source|
 148                         contacts.push source[k] if source.has_key?(k)
 149                 }
 150                 service[k] = contacts.sort.join(",") unless contacts.empty?
 151         }
 152 end
 153
 154 # Add the service definition service to hosts
 155 # f is the file for service definitions, deps the file for dependencies
 156 def addService(hosts, service, files, servers)
 157
 158         set_if_unset        service, 'use'               , SERVICE_TEMPLATE_NAME
 159         set_if_unset        service, 'max_check_attempts', MAX_CHECK_ATTEMPTS_DEFAULT
 160
 161         service['max_check_attempts'] = MAX_CHECK_ATTEMPTS_DEFAULT + service['max_check_attempts'] if service['max_check_attempts'] < 0
 162
 163         if service['nrpe']
 164                 throw "We already have a check_command (#{service['check_command']}) but we are in the NRPE block (nrpe: #{service['nrpe']})."+
 165                         "  This should have been caught much earlier" if service.has_key?('check_command');
 166
 167                 check = $nrpe.add(service['service_description'], service['nrpe'])
 168                 service['check_command'] = "#{ NRPE_CHECKNAME }!#{ check }"
 169
 170                 service['depends'] = ensure_array( service['depends'] )
 171                 service['depends'] << NRPE_PROCESS_SERVICE unless service['service_description'] == NRPE_PROCESS_SERVICE  # Depend on NRPE unless we are it
 172         end
 173
 174         hosts.sort.each{ |host|
 175                 s = service.clone
 176                 set_complain_if_set s, 'host_name', host, 'Service', s['service_description']
 177                 merge_contacts(servers[host], s)
 178
 179                 exclude_keys = %w(nrpe runfrom remotecheck
 180                                   depends
 181                                   hosts hostgroups excludehosts excludehostgroups)
 182                 if servers[host]['no-servicegroups']
 183                         exclude_keys << 'servicegroups'
 184                 end
 185                 print_block files['services'], 'service', s, exclude_keys
 186         }
 187
 188         if service['depends']
 189                 service['depends'].sort.each{ |prerequisite|
 190                         hosts.sort.each{ |host|
 191                                 prerequisite_host = host
 192                                 pre = prerequisite
 193                                 # split off a hostname if there's one
 194                                 bananasplit = prerequisite.split(':')
 195                                 if bananasplit.size == 2
 196                                         prerequisite_host = bananasplit[0]
 197                                         pre = bananasplit[1]
 198                                 elsif bananasplit.size > 2
 199                                         throw "Cannot prase prerequisite #{prerequisite} for service #{service['service_description']} into host:service"
 200                                 end
 201                                 dependency = {
 202                                         'host_name'                     => prerequisite_host,
 203                                         'service_description'           => pre,
 204                                         'dependent_host_name'           => host,
 205                                         'dependent_service_description' => service['service_description'],
 206                                         'execution_failure_criteria'    => 'n',
 207                                         'notification_failure_criteria' => 'w,u,c'
 208                                 };
 209                                 print_block files['dependencies'], 'servicedependency', dependency, %w()
 210                         }
 211                 }
 212         end
 213
 214
 215         set_complain_if_set service['_extinfo'], 'service_description' , service['service_description'], 'serviceextinfo', service['service_description']
 216         set_complain_if_set service['_extinfo'], 'host_name'           , hosts.sort.join(',')          , 'serviceextinfo', service['service_description']
 217
 218         print_block files['serviceextinfo'], 'serviceextinfo', service['_extinfo'], %w()
 219 end
 220
 221 # hostlists in services can be given as both, single hosts and hostgroups
 222 # This functinn merges hostgroups and a simple list of hosts
 223 #
 224 # it also takes a prefix so that it can be used for excludelists as well
 225 def merge_hosts_and_hostgroups(service, servers, hostgroups, prefix)
 226         hosts = []
 227         hosts = service[prefix+'hosts'].split(/,/).map{ |x| x.strip } if service[prefix+'hosts']
 228         hosts.each{ |host|
 229                 throw "host #{host} does not exist - used in service #{service['service_description']}" unless servers[host]
 230         };
 231         if service[prefix+'hostgroups']
 232                 service[prefix+'hostgroups'].split(/,/).map{ |x| x.strip }.each{ |hg|
 233                         throw "hostgroup #{hg} does not exist - used in service #{service['service_description']}" unless hostgroups[hg]
 234                         hosts = hosts.concat hostgroups[hg]['_memberlist']
 235                 }
 236         end
 237
 238         return hosts
 239 end
 240
 241 # Figure out the hosts a given service applies to
 242 #
 243 # For a given service find the list of hosts minus excluded hosts that this service runs on
 244 def find_hosts(service, servers, hostgroups)
 245         hosts        = merge_hosts_and_hostgroups service, servers, hostgroups, ''
 246         excludehosts = merge_hosts_and_hostgroups service, servers, hostgroups, 'exclude'
 247
 248         excludehosts.uniq.each{ |host|
 249                 if hosts.delete(host) == nil
 250                         puts "info: [service #{service['service_description']}] not excluding host #{host} - it's not included anyway."
 251                 end
 252         }
 253
 254         return hosts
 255 end
 256
 257 # Move all elements that have a key that starts with "extinfo-"
 258 # into the _extinfo subhash
 259 def split_away_extinfo(hash)
 260         hash['_extinfo'] = {}
 261         hash.keys.each{ |key|
 262                 if key[0, 8] == 'extinfo-'
 263                         hash['_extinfo'][ key[8, key.length-8] ] = hash[key]
 264                         hash.delete(key);
 265                 end
 266         }
 267 end
 268
 269
 270 #############################################################################################
 271 #############################################################################################
 272 #############################################################################################
 273
 274 # Load the config
 275 config = YAML::load( File.open( 'nagios-master.cfg' ) )
 276
 277 files = {}
 278 # Remove old created files
 279 nagios_filename.each_pair{ |name, filename|
 280         files[name] = File.new(filename, "w")
 281 }
 282
 283 #################################
 284 # create a few hostgroups
 285 #################################
 286 # create the "all" and "pingable" hostgroups
 287 config['hostgroups']['all'] = {}
 288 config['hostgroups']['all']['alias'] = "all servers"
 289 config['hostgroups']['all']['private'] = true
 290 config['hostgroups']['pingable'] = {}
 291 config['hostgroups']['pingable']['alias'] = "pingable servers"
 292 config['hostgroups']['pingable']['private'] = true
 293
 294 config['hostgroups'].each_pair{ |name, hg|
 295         throw "Empty hostgroup or hostgroup #{name} not a hash" unless hg.kind_of?(Hash)
 296         split_away_extinfo hg
 297
 298         hg['_memberlist'] = []
 299 }
 300
 301 config['servers'].each_pair{ |name, server|
 302         throw "Empty server or server #{name} not a hash" unless server.kind_of?(Hash)
 303
 304         split_away_extinfo server
 305
 306         throw "No hostgroups defined for #{name}" unless server['hostgroups']
 307         server['_hostgroups'] = server['hostgroups'].split(/,/).map{ |x| x.strip };
 308         server['_hostgroups'] << 'all'
 309         server['_hostgroups'] << 'pingable' unless server['pingable'] == false
 310
 311         server['_hostgroups'].each{ |hg|
 312                 throw "Hostgroup #{hg} is not defined" unless config['hostgroups'].has_key?(hg)
 313                 config['hostgroups'][hg]['_memberlist'] << name
 314         };
 315 }
 316
 317 config['servicegroups'] = {} unless config.has_key? 'servicegroups'
 318
 319 ##############
 320 # HOSTS
 321 ##############
 322 config['servers'].keys.sort.each{ |name|
 323         server = config['servers'][name]
 324         # Formerly we used 'ip' instead of 'address' in our source file
 325         # Handle this change but warn                                   XXX
 326         if server.has_key?('ip')
 327                 STDERR.puts("Host definition for #{name} has an 'ip' field.  Please use 'address' instead");
 328                 server['address'] = server['ip'];
 329                 server.delete('ip');
 330         end
 331
 332         set_complain_if_set server, 'host_name'    , name, 'Host', name
 333         set_if_unset        server, 'alias'        , name
 334         set_if_unset        server, 'use'          , HOST_TEMPLATE_NAME
 335         set_if_unset        server, 'check_command', HOST_ALIVE_CHECK    unless server['pingable'] == false
 336
 337         print_block files['hosts']      , 'host'       , server            , %w(hostgroups pingable no-servicegroups)
 338
 339
 340
 341         # Handle hostextinfo
 342         #config['hostgroups'][  server['_hostgroups'].first  ]['_extinfo'].each_pair{ |k, v|
 343         # find the first hostgroup that has extinfo
 344         extinfo = server['_hostgroups'].collect{ |hgname | config['hostgroups'][hgname]['_extinfo'] }.delete_if{ |ei| ei.size == 0 }.first
 345         if extinfo then
 346                 extinfo.each_pair do |k, v|
 347                         # substitute hostname into the notes_url
 348                         v = sprintf(v,name) if k == 'notes_url'
 349
 350                         set_if_unset server['_extinfo'], k ,v
 351                 end
 352         end
 353
 354         set_complain_if_set server['_extinfo'], 'host_name'       , name, 'hostextinfo', name
 355         set_if_unset        server['_extinfo'], 'vrml_image'      , server['_extinfo']['icon_image'] if server['_extinfo'].has_key?('icon_image')
 356         set_if_unset        server['_extinfo'], 'statusmap_image' , server['_extinfo']['icon_image'] if server['_extinfo'].has_key?('icon_image')
 357
 358         print_block files['hostextinfo'], 'hostextinfo', server['_extinfo'], %w()
 359 }
 360
 361
 362
 363 ##############
 364 # HOSTGROUPS
 365 ##############
 366 config['hostgroups'].keys.sort.each{ |name|
 367         hg = config['hostgroups'][name]
 368
 369         next if hg['private']
 370         throw "Empty hostgroup #{name}" if hg['_memberlist'].length == 0
 371
 372         set_complain_if_set hg, 'hostgroup_name', name                            , 'Hostgroup', name
 373         set_complain_if_set hg, 'members'       , hg['_memberlist'].sort.join(","), 'Hostgroup', name
 374
 375         print_block files['hostgroups'], 'hostgroup', hg, %w()
 376 }
 377
 378
 379 ##############
 380 # SERVICES and DEPENDENCIES
 381 ##############
 382 config['services'].each{ |service|
 383         throw "Empty service or service not a hash" unless service.kind_of?(Hash)
 384
 385         split_away_extinfo service
 386
 387         # make sure the depends list is an array
 388         service['depends'] = ensure_array( service['depends'] )
 389
 390         # Both 'name' and 'service_description' are valid for a service's name
 391         # Internally we only use service_description as that's nagios' official term
 392         if service.has_key?('name')
 393                 throw "Service definition has both a name (#{service['name']})" +
 394                       "and a service_description (#{service['service_description']})" if service.has_key?('service_description')
 395                 #STDERR.puts("Service definition #{service['name']} has a 'name' field.  Please use 'service_description' instead");
 396                 service['service_description'] = service['name'];
 397                 service.delete('name');
 398         end
 399         # Both 'check' and 'check_command' are valid for a service's check command
 400         # Internally we only use check_command as that's nagios' official term
 401         if service.has_key?('check')
 402                 throw "Service definition has both a check (#{service['check']})" +
 403                       "and a check_command (#{service['check_command']})" if service.has_key?('check_command')
 404                 #STDERR.puts("Service definition #{service['service_description']} has a 'check' field.  Please use 'check_command' instead");
 405                 service['check_command'] = service['check'];
 406                 service.delete('check');
 407         end
 408
 409
 410         hosts = find_hosts service, config['servers'], config['hostgroups']
 411         throw "no hosts for service #{service['service_description']}" if hosts.empty?
 412
 413         throw "nrpe, check, and remotecheck are mutually exclusive in service #{service['service_description']}" if
 414                 (service['nrpe'] ? 1 : 0) +
 415                 (service['check_command'] ? 1 : 0) +
 416                 (service['remotecheck'] ? 1 : 0)  >= 2
 417
 418         if service['runfrom'] && service['remotecheck']
 419                 # If the service check is to be run from a remote monitor server ("relay")
 420                 # add that as an NRPE check to be run on the relay and make this
 421                 # service also depend on NRPE on the relay
 422                 relay = service['runfrom']
 423
 424                 hosts.sort.each{ |host|
 425                         # how to recursively copy this thing?
 426                         hostservice = YAML::load( service.to_yaml )
 427                         host_ip = config['servers'][host]['address']
 428
 429                         remotecheck = hostservice['remotecheck']
 430                         if remotecheck.include?('$HOSTADDRESS$') and not host_ip
 431                                 throw "For some reason I do not have an address for #{host} yet I need it for the remote check.  This shouldn't be."
 432                         end
 433                         remotecheck.gsub!(/\$HOSTADDRESS\$/, host_ip) if host_ip
 434                         remotecheck.gsub!(/\$HOSTNAME\$/, host)
 435                         check = $nrpe.add("#{host}_#{hostservice['service_description']}", remotecheck)
 436                         hostservice['check_command'] = "#{NRPE_CHECKNAME_HOST}!#{ config['servers'][ relay ]['address'] }!#{ check }"
 437
 438                         # Make sure dependencies are an array.  If there are none, create an empty array
 439                         # if depends is just a string, make a list with just that element
 440                         hostservice['depends'] = ensure_array( hostservice['depends'] )
 441                         # And append this new dependency
 442                         hostservice['depends'] << "#{ relay }:#{ NRPE_PROCESS_SERVICE }";
 443
 444                         addService( [ host ], hostservice, files, config['servers'])
 445                 }
 446         elsif service['runfrom'] || service['remotecheck']
 447                 throw "runfrom and remotecheck must either appear both or not at all in service #{service['service_description']}"
 448                 throw "must not remotecheck without runfrom" if service['remotecheck']
 449         else
 450                 addService(hosts, service, files, config['servers'])
 451         end
 452 }
 453
 454
 455
 456 ##############
 457 # SERVICEGROUPS
 458 ##############
 459 config['servicegroups'].keys.sort.each{ |name|
 460         sg = config['servicegroups'][name]
 461
 462         set_complain_if_set sg, 'servicegroup_name', name                       , 'Servicegroup', name
 463
 464         print_block files['servicegroups'], 'servicegroup', sg, %w()
 465 }
 466
 467
 468 ##############
 469 # NRPE config file
 470 ##############
 471 $nrpe.checks.keys.sort.each{ |name|
 472         check = $nrpe.checks[name]
 473         files['nrpe'].puts "command[#{ name }]=#{ check }"
 474 }
 475
 476