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 underscre)
 131 def print_block(fd, kind, hash, exclude_keys)
 132         fd.puts "define #{kind} {"
 133         hash.each_pair{ |key, value|
 134                 next if key[0,1] == '_'
 135                 next if exclude_keys.include? key
 136                 fd.puts "       #{key}          #{value}"
 137         }
 138         fd.puts "}"
 139         fd.puts
 140 end
 141
 142 def merge_contacts(host, service)
 143         %w{contacts contact_groups}.each{ |k|
 144                 contacts = []
 145                 [host, service].each{ |source|
 146                         contacts.push source[k] if source.has_key?(k)
 147                 }
 148                 service[k] = contacts.join(",") unless contacts.empty?
 149         }
 150 end
 151
 152 # Add the service definition service to hosts
 153 # f is the file for service definitions, deps the file for dependencies
 154 def addService(hosts, service, files, servers)
 155
 156         set_if_unset        service, 'use'               , SERVICE_TEMPLATE_NAME
 157         set_if_unset        service, 'max_check_attempts', MAX_CHECK_ATTEMPTS_DEFAULT
 158
 159         service['max_check_attempts'] = MAX_CHECK_ATTEMPTS_DEFAULT + service['max_check_attempts'] if service['max_check_attempts'] < 0
 160
 161         if service['nrpe']
 162                 throw "We already have a check_command (#{service['check_command']}) but we are in the NRPE block (nrpe: #{service['nrpe']})."+
 163                         "  This should have been caught much earlier" if service.has_key?('check_command');
 164
 165                 check = $nrpe.add(service['service_description'], service['nrpe'])
 166                 service['check_command'] = "#{ NRPE_CHECKNAME }!#{ check }"
 167
 168                 service['depends'] = ensure_array( service['depends'] )
 169                 service['depends'] << NRPE_PROCESS_SERVICE unless service['service_description'] == NRPE_PROCESS_SERVICE  # Depend on NRPE unless we are it
 170         end
 171
 172         hosts.each{ |host|
 173                 s = service.clone
 174                 set_complain_if_set s, 'host_name', host, 'Service', s['service_description']
 175                 merge_contacts(servers[host], s)
 176
 177                 print_block files['services'], 'service', s, %w(nrpe runfrom remotecheck
 178                                                                 depends
 179                                                                 hosts hostgroups excludehosts excludehostgroups)
 180         }
 181
 182         if service['depends']
 183                 service['depends'].each{ |prerequisite|
 184                         hosts.each{ |host|
 185                                 prerequisite_host = host
 186                                 pre = prerequisite
 187                                 # split off a hostname if there's one
 188                                 bananasplit = prerequisite.split(':')
 189                                 if bananasplit.size == 2
 190                                         prerequisite_host = bananasplit[0]
 191                                         pre = bananasplit[1]
 192                                 elsif bananasplit.size > 2
 193                                         throw "Cannot prase prerequisite #{prerequisite} for service #{service['service_description']} into host:service"
 194                                 end
 195                                 dependency = {
 196                                         'host_name'                     => prerequisite_host,
 197                                         'service_description'           => pre,
 198                                         'dependent_host_name'           => host,
 199                                         'dependent_service_description' => service['service_description'],
 200                                         'execution_failure_criteria'    => 'n',
 201                                         'notification_failure_criteria' => 'w,u,c'
 202                                 };
 203                                 print_block files['dependencies'], 'servicedependency', dependency, %w()
 204                         }
 205                 }
 206         end
 207
 208
 209         set_complain_if_set service['_extinfo'], 'service_description' , service['service_description'], 'serviceextinfo', service['service_description']
 210         set_complain_if_set service['_extinfo'], 'host_name'           , hosts.join(',')               , 'serviceextinfo', service['service_description']
 211
 212         print_block files['serviceextinfo'], 'serviceextinfo', service['_extinfo'], %w()
 213 end
 214
 215 # hostlists in services can be given as both, single hosts and hostgroups
 216 # This functinn merges hostgroups and a simple list of hosts
 217 #
 218 # it also takes a prefix so that it can be used for excludelists as well
 219 def merge_hosts_and_hostgroups(service, servers, hostgroups, prefix)
 220         hosts = []
 221         hosts = service[prefix+'hosts'].split(/,/).map{ |x| x.strip } if service[prefix+'hosts']
 222         hosts.each{ |host|
 223                 throw "host #{host} does not exist - used in service #{service['service_description']}" unless servers[host]
 224         };
 225         if service[prefix+'hostgroups']
 226                 service[prefix+'hostgroups'].split(/,/).map{ |x| x.strip }.each{ |hg|
 227                         throw "hostgroup #{hg} does not exist - used in service #{service['service_description']}" unless hostgroups[hg]
 228                         hosts = hosts.concat hostgroups[hg]['_memberlist']
 229                 }
 230         end
 231
 232         return hosts
 233 end
 234
 235 # Figure out the hosts a given service applies to
 236 #
 237 # For a given service find the list of hosts minus excluded hosts that this service runs on
 238 def find_hosts(service, servers, hostgroups)
 239         hosts        = merge_hosts_and_hostgroups service, servers, hostgroups, ''
 240         excludehosts = merge_hosts_and_hostgroups service, servers, hostgroups, 'exclude'
 241
 242         excludehosts.uniq.each{ |host|
 243                 if hosts.delete(host) == nil
 244                         throw "Cannot remove host #{host} from service #{service['service_description']}: it's not included anyway."
 245                 end
 246         }
 247
 248         return hosts
 249 end
 250
 251 # Move all elements that have a key that starts with "extinfo-"
 252 # into the _extinfo subhash
 253 def split_away_extinfo(hash)
 254         hash['_extinfo'] = {}
 255         hash.keys.each{ |key|
 256                 if key[0, 8] == 'extinfo-'
 257                         hash['_extinfo'][ key[8, key.length-8] ] = hash[key]
 258                         hash.delete(key);
 259                 end
 260         }
 261 end
 262
 263
 264 #############################################################################################
 265 #############################################################################################
 266 #############################################################################################
 267
 268 # Load the config
 269 config = YAML::load( File.open( 'nagios-master.cfg' ) )
 270
 271 files = {}
 272 # Remove old created files
 273 nagios_filename.each_pair{ |name, filename|
 274         files[name] = File.new(filename, "w")
 275 }
 276
 277 #################################
 278 # create a few hostgroups
 279 #################################
 280 # create the "all" and "pingable" hostgroups
 281 config['hostgroups']['all'] = {}
 282 config['hostgroups']['all']['alias'] = "all servers"
 283 config['hostgroups']['all']['private'] = true
 284 config['hostgroups']['pingable'] = {}
 285 config['hostgroups']['pingable']['alias'] = "pingable servers"
 286 config['hostgroups']['pingable']['private'] = true
 287
 288 config['hostgroups'].each_pair{ |name, hg|
 289         throw "Empty hostgroup or hostgroup #{name} not a hash" unless hg.kind_of?(Hash)
 290         split_away_extinfo hg
 291
 292         hg['_memberlist'] = []
 293 }
 294
 295 config['servers'].each_pair{ |name, server|
 296         throw "Empty server or server #{name} not a hash" unless server.kind_of?(Hash)
 297
 298         split_away_extinfo server
 299
 300         throw "No hostgroups defined for #{name}" unless server['hostgroups']
 301         server['_hostgroups'] = server['hostgroups'].split(/,/).map{ |x| x.strip };
 302         server['_hostgroups'] << 'all'
 303         server['_hostgroups'] << 'pingable' unless server['pingable'] == false
 304
 305         server['_hostgroups'].each{ |hg|
 306                 throw "Hostgroup #{hg} is not defined" unless config['hostgroups'].has_key?(hg)
 307                 config['hostgroups'][hg]['_memberlist'] << name
 308         };
 309 }
 310
 311 config['servicegroups'] = {} unless config.has_key? 'servicegroups'
 312
 313 ##############
 314 # HOSTS
 315 ##############
 316 config['servers'].each_pair{ |name, server|
 317         # Formerly we used 'ip' instead of 'address' in our source file
 318         # Handle this change but warn                                   XXX
 319         if server.has_key?('ip')
 320                 STDERR.puts("Host definition for #{name} has an 'ip' field.  Please use 'address' instead");
 321                 server['address'] = server['ip'];
 322                 server.delete('ip');
 323         end
 324
 325         set_complain_if_set server, 'host_name'    , name, 'Host', name
 326         set_if_unset        server, 'alias'        , name
 327         set_if_unset        server, 'use'          , HOST_TEMPLATE_NAME
 328         set_if_unset        server, 'check_command', HOST_ALIVE_CHECK    unless server['pingable'] == false
 329
 330         print_block files['hosts']      , 'host'       , server            , %w(hostgroups pingable)
 331
 332
 333
 334         # Handle hostextinfo
 335         #config['hostgroups'][  server['_hostgroups'].first  ]['_extinfo'].each_pair{ |k, v|
 336         # find the first hostgroup that has extinfo
 337         extinfo = server['_hostgroups'].collect{ |hgname | config['hostgroups'][hgname]['_extinfo'] }.delete_if{ |ei| ei.size == 0 }.first
 338         if extinfo then
 339                 extinfo.each_pair do |k, v|
 340                         # substitute hostname into the notes_url
 341                         v = sprintf(v,name) if k == 'notes_url'
 342
 343                         set_if_unset server['_extinfo'], k ,v
 344                 end
 345         end
 346
 347         set_complain_if_set server['_extinfo'], 'host_name'       , name, 'hostextinfo', name
 348         set_if_unset        server['_extinfo'], 'vrml_image'      , server['_extinfo']['icon_image'] if server['_extinfo'].has_key?('icon_image')
 349         set_if_unset        server['_extinfo'], 'statusmap_image' , server['_extinfo']['icon_image'] if server['_extinfo'].has_key?('icon_image')
 350
 351         print_block files['hostextinfo'], 'hostextinfo', server['_extinfo'], %w()
 352 }
 353
 354
 355
 356 ##############
 357 # HOSTGROUPS
 358 ##############
 359 config['hostgroups'].each_pair{ |name, hg|
 360         next if hg['private']
 361         throw "Empty hostgroup #{name}" if hg['_memberlist'].length == 0
 362
 363         set_complain_if_set hg, 'hostgroup_name', name                       , 'Hostgroup', name
 364         set_complain_if_set hg, 'members'       , hg['_memberlist'].join(","), 'Hostgroup', name
 365
 366         print_block files['hostgroups'], 'hostgroup', hg, %w()
 367 }
 368
 369
 370 ##############
 371 # SERVICES and DEPENDENCIES
 372 ##############
 373 config['services'].each{ |service|
 374         throw "Empty service or service not a hash" unless service.kind_of?(Hash)
 375
 376         split_away_extinfo service
 377
 378
 379         # Both 'name' and 'service_description' are valid for a service's name
 380         # Internally we only use service_description as that's nagios' official term
 381         if service.has_key?('name')
 382                 throw "Service definition has both a name (#{service['name']})" +
 383                       "and a service_description (#{service['service_description']})" if service.has_key?('service_description')
 384                 #STDERR.puts("Service definition #{service['name']} has a 'name' field.  Please use 'service_description' instead");
 385                 service['service_description'] = service['name'];
 386                 service.delete('name');
 387         end
 388         # Both 'check' and 'check_command' are valid for a service's check command
 389         # Internally we only use check_command as that's nagios' official term
 390         if service.has_key?('check')
 391                 throw "Service definition has both a check (#{service['check']})" +
 392                       "and a check_command (#{service['check_command']})" if service.has_key?('check_command')
 393                 #STDERR.puts("Service definition #{service['service_description']} has a 'check' field.  Please use 'check_command' instead");
 394                 service['check_command'] = service['check'];
 395                 service.delete('check');
 396         end
 397
 398
 399         hosts = find_hosts service, config['servers'], config['hostgroups']
 400         throw "no hosts for service #{service['service_description']}" if hosts.empty?
 401
 402         throw "nrpe, check, and remotecheck are mutually exclusive in service #{service['service_description']}" if
 403                 (service['nrpe'] ? 1 : 0) +
 404                 (service['check_command'] ? 1 : 0) +
 405                 (service['remotecheck'] ? 1 : 0)  >= 2
 406
 407         if service['runfrom'] && service['remotecheck']
 408                 # If the service check is to be run from a remote monitor server ("relay")
 409                 # add that as an NRPE check to be run on the relay and make this
 410                 # service also depend on NRPE on the relay
 411                 relay = service['runfrom']
 412
 413                 hosts.each{ |host|
 414                         # how to recursively copy this thing?
 415                         hostservice = YAML::load( service.to_yaml )
 416                         host_ip = config['servers'][host]['address']
 417
 418                         remotecheck = hostservice['remotecheck']
 419                         if remotecheck.include?('$HOSTADDRESS$') and not host_ip
 420                                 throw "For some reason I do not have an address for #{host} yet I need it for the remote check.  This shouldn't be."
 421                         end
 422                         remotecheck.gsub!(/\$HOSTADDRESS\$/, host_ip) if host_ip
 423                         remotecheck.gsub!(/\$HOSTNAME\$/, host)
 424                         check = $nrpe.add("#{host}_#{hostservice['service_description']}", remotecheck)
 425                         hostservice['check_command'] = "#{NRPE_CHECKNAME_HOST}!#{ config['servers'][ relay ]['address'] }!#{ check }"
 426
 427                         # Make sure dependencies are an array.  If there are none, create an empty array
 428                         # if depends is just a string, make a list with just that element
 429                         hostservice['depends'] = ensure_array( hostservice['depends'] )
 430                         # And append this new dependency
 431                         hostservice['depends'] << "#{ relay }:#{ NRPE_PROCESS_SERVICE }";
 432
 433                         addService( [ host ], hostservice, files, config['servers'])
 434                 }
 435         elsif service['runfrom'] || service['remotecheck']
 436                 throw "runfrom and remotecheck must either appear both or not at all in service #{service['service_description']}"
 437                 throw "must not remotecheck without runfrom" if service['remotecheck']
 438         else
 439                 addService(hosts, service, files, config['servers'])
 440         end
 441 }
 442
 443
 444
 445 ##############
 446 # SERVICEGROUPS
 447 ##############
 448 config['servicegroups'].each_pair{ |name, sg|
 449         set_complain_if_set sg, 'servicegroup_name', name                       , 'Servicegroup', name
 450
 451         print_block files['servicegroups'], 'servicegroup', sg, %w()
 452 }
 453
 454
 455 ##############
 456 # NRPE config file
 457 ##############
 458 $nrpe.checks.each_pair{ |name, check|
 459         files['nrpe'].puts "command[#{ name }]=#{ check }"
 460 }
 461
 462