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