services/api/app/models/job.rb

   1 # Copyright (C) The Arvados Authors. All rights reserved.
   2 #
   3 # SPDX-License-Identifier: AGPL-3.0
   4
   5 require 'log_reuse_info'
   6 require 'safe_json'
   7
   8 class Job < ArvadosModel
   9   include HasUuid
  10   include KindAndEtag
  11   include CommonApiTemplate
  12   extend CurrentApiClient
  13   extend LogReuseInfo
  14   serialize :components, Hash
  15   serialize :script_parameters, Hash
  16   serialize :runtime_constraints, Hash
  17   serialize :tasks_summary, Hash
  18   before_create :ensure_unique_submit_id
  19   after_commit :trigger_crunch_dispatch_if_cancelled, :on => :update
  20   before_validation :set_priority
  21   before_validation :update_state_from_old_state_attrs
  22   before_validation :update_script_parameters_digest
  23   validate :ensure_script_version_is_commit
  24   validate :find_docker_image_locator
  25   validate :find_arvados_sdk_version
  26   validate :validate_status
  27   validate :validate_state_change
  28   validate :ensure_no_collection_uuids_in_script_params
  29   before_save :tag_version_in_internal_repository
  30   before_save :update_timestamps_when_state_changes
  31
  32   has_many :commit_ancestors, :foreign_key => :descendant, :primary_key => :script_version
  33   has_many(:nodes, foreign_key: :job_uuid, primary_key: :uuid)
  34
  35   class SubmitIdReused < RequestError
  36   end
  37
  38   api_accessible :user, extend: :common do |t|
  39     t.add :submit_id
  40     t.add :priority
  41     t.add :script
  42     t.add :script_parameters
  43     t.add :script_version
  44     t.add :cancelled_at
  45     t.add :cancelled_by_client_uuid
  46     t.add :cancelled_by_user_uuid
  47     t.add :started_at
  48     t.add :finished_at
  49     t.add :output
  50     t.add :success
  51     t.add :running
  52     t.add :state
  53     t.add :is_locked_by_uuid
  54     t.add :log
  55     t.add :runtime_constraints
  56     t.add :tasks_summary
  57     t.add :nondeterministic
  58     t.add :repository
  59     t.add :supplied_script_version
  60     t.add :arvados_sdk_version
  61     t.add :docker_image_locator
  62     t.add :queue_position
  63     t.add :node_uuids
  64     t.add :description
  65     t.add :components
  66   end
  67
  68   # Supported states for a job
  69   States = [
  70             (Queued = 'Queued'),
  71             (Running = 'Running'),
  72             (Cancelled = 'Cancelled'),
  73             (Failed = 'Failed'),
  74             (Complete = 'Complete'),
  75            ]
  76
  77   after_initialize do
  78     @need_crunch_dispatch_trigger = false
  79   end
  80
  81   def self.limit_index_columns_read
  82     ["components"]
  83   end
  84
  85   def self.protected_attributes
  86     [:arvados_sdk_version, :docker_image_locator]
  87   end
  88
  89   def assert_finished
  90     update_attributes(finished_at: finished_at || db_current_time,
  91                       success: success.nil? ? false : success,
  92                       running: false)
  93   end
  94
  95   def node_uuids
  96     nodes.map(&:uuid)
  97   end
  98
  99   def self.queue
 100     self.where('state = ?', Queued).order('priority desc, created_at')
 101   end
 102
 103   def queue_position
 104     # We used to report this accurately, but the implementation made queue
 105     # API requests O(n**2) for the size of the queue.  See #8800.
 106     # We've soft-disabled it because it's not clear we even want this
 107     # functionality: now that we have Node Manager with support for multiple
 108     # node sizes, "queue position" tells you very little about when a job will
 109     # run.
 110     state == Queued ? 0 : nil
 111   end
 112
 113   def self.running
 114     self.where('running = ?', true).
 115       order('priority desc, created_at')
 116   end
 117
 118   def lock locked_by_uuid
 119     with_lock do
 120       unless self.state == Queued and self.is_locked_by_uuid.nil?
 121         raise AlreadyLockedError
 122       end
 123       self.state = Running
 124       self.is_locked_by_uuid = locked_by_uuid
 125       self.save!
 126     end
 127   end
 128
 129   def update_script_parameters_digest
 130     self.script_parameters_digest = self.class.sorted_hash_digest(script_parameters)
 131   end
 132
 133   def self.searchable_columns operator
 134     super - ["script_parameters_digest"]
 135   end
 136
 137   def self.full_text_searchable_columns
 138     super - ["script_parameters_digest"]
 139   end
 140
 141   def self.load_job_specific_filters attrs, orig_filters, read_users
 142     # Convert Job-specific @filters entries into general SQL filters.
 143     script_info = {"repository" => nil, "script" => nil}
 144     git_filters = Hash.new do |hash, key|
 145       hash[key] = {"max_version" => "HEAD", "exclude_versions" => []}
 146     end
 147     filters = []
 148     orig_filters.each do |attr, operator, operand|
 149       if (script_info.has_key? attr) and (operator == "=")
 150         if script_info[attr].nil?
 151           script_info[attr] = operand
 152         elsif script_info[attr] != operand
 153           raise ArgumentError.new("incompatible #{attr} filters")
 154         end
 155       end
 156       case operator
 157       when "in git"
 158         git_filters[attr]["min_version"] = operand
 159       when "not in git"
 160         git_filters[attr]["exclude_versions"] += Array.wrap(operand)
 161       when "in docker", "not in docker"
 162         image_hashes = Array.wrap(operand).flat_map do |search_term|
 163           image_search, image_tag = search_term.split(':', 2)
 164           Collection.
 165             find_all_for_docker_image(image_search, image_tag, read_users, filter_compatible_format: false).
 166             map(&:portable_data_hash)
 167         end
 168         filters << [attr, operator.sub(/ docker$/, ""), image_hashes]
 169       else
 170         filters << [attr, operator, operand]
 171       end
 172     end
 173
 174     # Build a real script_version filter from any "not? in git" filters.
 175     git_filters.each_pair do |attr, filter|
 176       case attr
 177       when "script_version"
 178         script_info.each_pair do |key, value|
 179           if value.nil?
 180             raise ArgumentError.new("script_version filter needs #{key} filter")
 181           end
 182         end
 183         filter["repository"] = script_info["repository"]
 184         if attrs[:script_version]
 185           filter["max_version"] = attrs[:script_version]
 186         else
 187           # Using HEAD, set earlier by the hash default, is fine.
 188         end
 189       when "arvados_sdk_version"
 190         filter["repository"] = "arvados"
 191       else
 192         raise ArgumentError.new("unknown attribute for git filter: #{attr}")
 193       end
 194       revisions = Commit.find_commit_range(filter["repository"],
 195                                            filter["min_version"],
 196                                            filter["max_version"],
 197                                            filter["exclude_versions"])
 198       if revisions.empty?
 199         raise ArgumentError.
 200           new("error searching #{filter['repository']} from " +
 201               "'#{filter['min_version']}' to '#{filter['max_version']}', " +
 202               "excluding #{filter['exclude_versions']}")
 203       end
 204       filters.append([attr, "in", revisions])
 205     end
 206
 207     filters
 208   end
 209
 210   def self.find_reusable attrs, params, filters, read_users
 211     if filters.empty?  # Translate older creation parameters into filters.
 212       filters =
 213         [["repository", "=", attrs[:repository]],
 214          ["script", "=", attrs[:script]],
 215          ["script_version", "not in git", params[:exclude_script_versions]],
 216         ].reject { |filter| filter.last.nil? or filter.last.empty? }
 217       if !params[:minimum_script_version].blank?
 218         filters << ["script_version", "in git",
 219                      params[:minimum_script_version]]
 220       else
 221         filters += default_git_filters("script_version", attrs[:repository],
 222                                        attrs[:script_version])
 223       end
 224       if image_search = attrs[:runtime_constraints].andand["docker_image"]
 225         if image_tag = attrs[:runtime_constraints]["docker_image_tag"]
 226           image_search += ":#{image_tag}"
 227         end
 228         image_locator = Collection.
 229           for_latest_docker_image(image_search).andand.portable_data_hash
 230       else
 231         image_locator = nil
 232       end
 233       filters << ["docker_image_locator", "=", image_locator]
 234       if sdk_version = attrs[:runtime_constraints].andand["arvados_sdk_version"]
 235         filters += default_git_filters("arvados_sdk_version", "arvados", sdk_version)
 236       end
 237       filters = load_job_specific_filters(attrs, filters, read_users)
 238     end
 239
 240     # Check specified filters for some reasonableness.
 241     filter_names = filters.map { |f| f.first }.uniq
 242     ["repository", "script"].each do |req_filter|
 243       if not filter_names.include?(req_filter)
 244         return send_error("#{req_filter} filter required")
 245       end
 246     end
 247
 248     # Search for a reusable Job, and return it if found.
 249     candidates = Job.readable_by(current_user)
 250     log_reuse_info { "starting with #{candidates.count} jobs readable by current user #{current_user.uuid}" }
 251
 252     candidates = candidates.where(
 253       'state = ? or (owner_uuid = ? and state in (?))',
 254       Job::Complete, current_user.uuid, [Job::Queued, Job::Running])
 255     log_reuse_info(candidates) { "after filtering on job state ((state=Complete) or (state=Queued/Running and (submitted by current user)))" }
 256
 257     digest = Job.sorted_hash_digest(attrs[:script_parameters])
 258     candidates = candidates.where('script_parameters_digest = ?', digest)
 259     log_reuse_info(candidates) { "after filtering on script_parameters_digest #{digest}" }
 260
 261     candidates = candidates.where('nondeterministic is distinct from ?', true)
 262     log_reuse_info(candidates) { "after filtering on !nondeterministic" }
 263
 264     # prefer Running jobs over Queued
 265     candidates = candidates.order('state desc, created_at')
 266
 267     candidates = apply_filters candidates, filters
 268     log_reuse_info(candidates) { "after filtering on repo, script, and custom filters #{filters.inspect}" }
 269
 270     chosen = nil
 271     chosen_output = nil
 272     incomplete_job = nil
 273     candidates.each do |j|
 274       if j.state != Job::Complete
 275         if !incomplete_job
 276           # We'll use this if we don't find a job that has completed
 277           log_reuse_info { "job #{j.uuid} is reusable, but unfinished; continuing search for completed jobs" }
 278           incomplete_job = j
 279         else
 280           log_reuse_info { "job #{j.uuid} is unfinished and we already have #{incomplete_job.uuid}; ignoring" }
 281         end
 282       elsif chosen == false
 283         # Ignore: we have already decided not to reuse any completed
 284         # job.
 285         log_reuse_info { "job #{j.uuid} with output #{j.output} ignored, see above" }
 286       elsif j.output.nil?
 287         log_reuse_info { "job #{j.uuid} has nil output" }
 288       elsif j.log.nil?
 289         log_reuse_info { "job #{j.uuid} has nil log" }
 290       elsif Rails.configuration.Containers.JobsAPI.ReuseJobIfOutputsDiffer
 291         if !Collection.readable_by(current_user).find_by_portable_data_hash(j.output)
 292           # Ignore: keep looking for an incomplete job or one whose
 293           # output is readable.
 294           log_reuse_info { "job #{j.uuid} output #{j.output} unavailable to user; continuing search" }
 295         elsif !Collection.readable_by(current_user).find_by_portable_data_hash(j.log)
 296           # Ignore: keep looking for an incomplete job or one whose
 297           # log is readable.
 298           log_reuse_info { "job #{j.uuid} log #{j.log} unavailable to user; continuing search" }
 299         else
 300           log_reuse_info { "job #{j.uuid} with output #{j.output} is reusable; decision is final." }
 301           return j
 302         end
 303       elsif chosen_output
 304         if chosen_output != j.output
 305           # If two matching jobs produced different outputs, run a new
 306           # job (or use one that's already running/queued) instead of
 307           # choosing one arbitrarily.
 308           log_reuse_info { "job #{j.uuid} output #{j.output} disagrees; forgetting about #{chosen.uuid} and ignoring any other finished jobs (see reuse_job_if_outputs_differ in application.default.yml)" }
 309           chosen = false
 310         else
 311           log_reuse_info { "job #{j.uuid} output #{j.output} agrees with chosen #{chosen.uuid}; continuing search in case other candidates have different outputs" }
 312         end
 313         # ...and that's the only thing we need to do once we've chosen
 314         # a job to reuse.
 315       elsif !Collection.readable_by(current_user).find_by_portable_data_hash(j.output)
 316         # This user cannot read the output of this job. Any other
 317         # completed job will have either the same output (making it
 318         # unusable) or a different output (making it unusable because
 319         # reuse_job_if_outputs_different is turned off). Therefore,
 320         # any further investigation of reusable jobs is futile.
 321         log_reuse_info { "job #{j.uuid} output #{j.output} is unavailable to user; this means no finished job can be reused (see reuse_job_if_outputs_differ in application.default.yml)" }
 322         chosen = false
 323       elsif !Collection.readable_by(current_user).find_by_portable_data_hash(j.log)
 324         # This user cannot read the log of this job, don't try to reuse the
 325         # job but consider if the output is consistent.
 326         log_reuse_info { "job #{j.uuid} log #{j.log} is unavailable to user; continuing search" }
 327         chosen_output = j.output
 328       else
 329         log_reuse_info { "job #{j.uuid} with output #{j.output} can be reused; continuing search in case other candidates have different outputs" }
 330         chosen = j
 331         chosen_output = j.output
 332       end
 333     end
 334     j = chosen || incomplete_job
 335     if j
 336       log_reuse_info { "done, #{j.uuid} was selected" }
 337     else
 338       log_reuse_info { "done, nothing suitable" }
 339     end
 340     return j
 341   end
 342
 343   def self.default_git_filters(attr_name, repo_name, refspec)
 344     # Add a filter to @filters for `attr_name` = the latest commit available
 345     # in `repo_name` at `refspec`.  No filter is added if refspec can't be
 346     # resolved.
 347     commits = Commit.find_commit_range(repo_name, nil, refspec, nil)
 348     if commit_hash = commits.first
 349       [[attr_name, "=", commit_hash]]
 350     else
 351       []
 352     end
 353   end
 354
 355   def cancel(cascade: false, need_transaction: true)
 356     if need_transaction
 357       ActiveRecord::Base.transaction do
 358         cancel(cascade: cascade, need_transaction: false)
 359       end
 360       return
 361     end
 362
 363     if self.state.in?([Queued, Running])
 364       self.state = Cancelled
 365       self.save!
 366     elsif self.state != Cancelled
 367       raise InvalidStateTransitionError
 368     end
 369
 370     return if !cascade
 371
 372     # cancel all children; they could be jobs or pipeline instances
 373     children = self.components.andand.collect{|_, u| u}.compact
 374
 375     return if children.empty?
 376
 377     # cancel any child jobs
 378     Job.where(uuid: children, state: [Queued, Running]).each do |job|
 379       job.cancel(cascade: cascade, need_transaction: false)
 380     end
 381
 382     # cancel any child pipelines
 383     PipelineInstance.where(uuid: children, state: [PipelineInstance::RunningOnServer, PipelineInstance::RunningOnClient]).each do |pi|
 384       pi.cancel(cascade: cascade, need_transaction: false)
 385     end
 386   end
 387
 388   protected
 389
 390   def self.sorted_hash_digest h
 391     Digest::MD5.hexdigest(Oj.dump(deep_sort_hash(h)))
 392   end
 393
 394   def foreign_key_attributes
 395     super + %w(output log)
 396   end
 397
 398   def skip_uuid_read_permission_check
 399     super + %w(cancelled_by_client_uuid)
 400   end
 401
 402   def skip_uuid_existence_check
 403     super + %w(output log)
 404   end
 405
 406   def set_priority
 407     if self.priority.nil?
 408       self.priority = 0
 409     end
 410     true
 411   end
 412
 413   def ensure_script_version_is_commit
 414     if state == Running
 415       # Apparently client has already decided to go for it. This is
 416       # needed to run a local job using a local working directory
 417       # instead of a commit-ish.
 418       return true
 419     end
 420     if new_record? or repository_changed? or script_version_changed?
 421       sha1 = Commit.find_commit_range(repository,
 422                                       nil, script_version, nil).first
 423       if not sha1
 424         errors.add :script_version, "#{script_version} does not resolve to a commit"
 425         return false
 426       end
 427       if supplied_script_version.nil? or supplied_script_version.empty?
 428         self.supplied_script_version = script_version
 429       end
 430       self.script_version = sha1
 431     end
 432     true
 433   end
 434
 435   def tag_version_in_internal_repository
 436     if state == Running
 437       # No point now. See ensure_script_version_is_commit.
 438       true
 439     elsif errors.any?
 440       # Won't be saved, and script_version might not even be valid.
 441       true
 442     elsif new_record? or repository_changed? or script_version_changed?
 443       uuid_was = uuid
 444       begin
 445         assign_uuid
 446         Commit.tag_in_internal_repository repository, script_version, uuid
 447       rescue
 448         self.uuid = uuid_was
 449         raise
 450       end
 451     end
 452   end
 453
 454   def ensure_unique_submit_id
 455     if !submit_id.nil?
 456       if Job.where('submit_id=?',self.submit_id).first
 457         raise SubmitIdReused.new
 458       end
 459     end
 460     true
 461   end
 462
 463   def resolve_runtime_constraint(key, attr_sym)
 464     if ((runtime_constraints.is_a? Hash) and
 465         (search = runtime_constraints[key]))
 466       ok, result = yield search
 467     else
 468       ok, result = true, nil
 469     end
 470     if ok
 471       send("#{attr_sym}=".to_sym, result)
 472     else
 473       errors.add(attr_sym, result)
 474     end
 475     ok
 476   end
 477
 478   def find_arvados_sdk_version
 479     resolve_runtime_constraint("arvados_sdk_version",
 480                                :arvados_sdk_version) do |git_search|
 481       commits = Commit.find_commit_range("arvados",
 482                                          nil, git_search, nil)
 483       if commits.empty?
 484         [false, "#{git_search} does not resolve to a commit"]
 485       elsif not runtime_constraints["docker_image"]
 486         [false, "cannot be specified without a Docker image constraint"]
 487       else
 488         [true, commits.first]
 489       end
 490     end
 491   end
 492
 493   def find_docker_image_locator
 494     if runtime_constraints.is_a? Hash and Rails.configuration.Containers.JobsAPI.DefaultDockerImage != ""
 495       runtime_constraints['docker_image'] ||=
 496         Rails.configuration.Containers.JobsAPI.DefaultDockerImage
 497     end
 498
 499     resolve_runtime_constraint("docker_image",
 500                                :docker_image_locator) do |image_search|
 501       image_tag = runtime_constraints['docker_image_tag']
 502       if coll = Collection.for_latest_docker_image(image_search, image_tag)
 503         [true, coll.portable_data_hash]
 504       else
 505         [false, "not found for #{image_search}"]
 506       end
 507     end
 508   end
 509
 510   def permission_to_update
 511     if is_locked_by_uuid_was and !(current_user and
 512                                    (current_user.uuid == is_locked_by_uuid_was or
 513                                     current_user.uuid == system_user.uuid))
 514       if script_changed? or
 515           script_parameters_changed? or
 516           script_version_changed? or
 517           (!cancelled_at_was.nil? and
 518            (cancelled_by_client_uuid_changed? or
 519             cancelled_by_user_uuid_changed? or
 520             cancelled_at_changed?)) or
 521           started_at_changed? or
 522           finished_at_changed? or
 523           running_changed? or
 524           success_changed? or
 525           output_changed? or
 526           log_changed? or
 527           tasks_summary_changed? or
 528           (state_changed? && state != Cancelled) or
 529           components_changed?
 530         logger.warn "User #{current_user.uuid if current_user} tried to change protected job attributes on locked #{self.class.to_s} #{uuid_was}"
 531         return false
 532       end
 533     end
 534     if !is_locked_by_uuid_changed?
 535       super
 536     else
 537       if !current_user
 538         logger.warn "Anonymous user tried to change lock on #{self.class.to_s} #{uuid_was}"
 539         false
 540       elsif is_locked_by_uuid_was and is_locked_by_uuid_was != current_user.uuid
 541         logger.warn "User #{current_user.uuid} tried to steal lock on #{self.class.to_s} #{uuid_was} from #{is_locked_by_uuid_was}"
 542         false
 543       elsif !is_locked_by_uuid.nil? and is_locked_by_uuid != current_user.uuid
 544         logger.warn "User #{current_user.uuid} tried to lock #{self.class.to_s} #{uuid_was} with uuid #{is_locked_by_uuid}"
 545         false
 546       else
 547         super
 548       end
 549     end
 550   end
 551
 552   def update_modified_by_fields
 553     if self.cancelled_at_changed?
 554       # Ensure cancelled_at cannot be set to arbitrary non-now times,
 555       # or changed once it is set.
 556       if self.cancelled_at and not self.cancelled_at_was
 557         self.cancelled_at = db_current_time
 558         self.cancelled_by_user_uuid = current_user.uuid
 559         self.cancelled_by_client_uuid = current_api_client.andand.uuid
 560         @need_crunch_dispatch_trigger = true
 561       else
 562         self.cancelled_at = self.cancelled_at_was
 563         self.cancelled_by_user_uuid = self.cancelled_by_user_uuid_was
 564         self.cancelled_by_client_uuid = self.cancelled_by_client_uuid_was
 565       end
 566     end
 567     super
 568   end
 569
 570   def trigger_crunch_dispatch_if_cancelled
 571     if @need_crunch_dispatch_trigger
 572       File.open(Rails.configuration.Containers.JobsAPI.CrunchRefreshTrigger, 'wb') do
 573         # That's all, just create/touch a file for crunch-job to see.
 574       end
 575     end
 576   end
 577
 578   def update_timestamps_when_state_changes
 579     return if not (state_changed? or new_record?)
 580
 581     case state
 582     when Running
 583       self.started_at ||= db_current_time
 584     when Failed, Complete
 585       self.finished_at ||= db_current_time
 586     when Cancelled
 587       self.cancelled_at ||= db_current_time
 588     end
 589
 590     # TODO: Remove the following case block when old "success" and
 591     # "running" attrs go away. Until then, this ensures we still
 592     # expose correct success/running flags to older clients, even if
 593     # some new clients are writing only the new state attribute.
 594     case state
 595     when Queued
 596       self.running = false
 597       self.success = nil
 598     when Running
 599       self.running = true
 600       self.success = nil
 601     when Cancelled, Failed
 602       self.running = false
 603       self.success = false
 604     when Complete
 605       self.running = false
 606       self.success = true
 607     end
 608     self.running ||= false # Default to false instead of nil.
 609
 610     @need_crunch_dispatch_trigger = true
 611
 612     true
 613   end
 614
 615   def update_state_from_old_state_attrs
 616     # If a client has touched the legacy state attrs, update the
 617     # "state" attr to agree with the updated values of the legacy
 618     # attrs.
 619     #
 620     # TODO: Remove this method when old "success" and "running" attrs
 621     # go away.
 622     if cancelled_at_changed? or
 623         success_changed? or
 624         running_changed? or
 625         state.nil?
 626       if cancelled_at
 627         self.state = Cancelled
 628       elsif success == false
 629         self.state = Failed
 630       elsif success == true
 631         self.state = Complete
 632       elsif running == true
 633         self.state = Running
 634       else
 635         self.state = Queued
 636       end
 637     end
 638     true
 639   end
 640
 641   def validate_status
 642     if self.state.in?(States)
 643       true
 644     else
 645       errors.add :state, "#{state.inspect} must be one of: #{States.inspect}"
 646       false
 647     end
 648   end
 649
 650   def validate_state_change
 651     ok = true
 652     if self.state_changed?
 653       ok = case self.state_was
 654            when nil
 655              # state isn't set yet
 656              true
 657            when Queued
 658              # Permit going from queued to any state
 659              true
 660            when Running
 661              # From running, may only transition to a finished state
 662              [Complete, Failed, Cancelled].include? self.state
 663            when Complete, Failed, Cancelled
 664              # Once in a finished state, don't permit any more state changes
 665              false
 666            else
 667              # Any other state transition is also invalid
 668              false
 669            end
 670       if not ok
 671         errors.add :state, "invalid change from #{self.state_was} to #{self.state}"
 672       end
 673     end
 674     ok
 675   end
 676
 677   def ensure_no_collection_uuids_in_script_params
 678     # Fail validation if any script_parameters field includes a string containing a
 679     # collection uuid pattern.
 680     if self.script_parameters_changed?
 681       if recursive_hash_search(self.script_parameters, Collection.uuid_regex)
 682         self.errors.add :script_parameters, "must use portable_data_hash instead of collection uuid"
 683         return false
 684       end
 685     end
 686     true
 687   end
 688
 689   # recursive_hash_search searches recursively through hashes and
 690   # arrays in 'thing' for string fields matching regular expression
 691   # 'pattern'.  Returns true if pattern is found, false otherwise.
 692   def recursive_hash_search thing, pattern
 693     if thing.is_a? Hash
 694       thing.each do |k, v|
 695         return true if recursive_hash_search v, pattern
 696       end
 697     elsif thing.is_a? Array
 698       thing.each do |k|
 699         return true if recursive_hash_search k, pattern
 700       end
 701     elsif thing.is_a? String
 702       return true if thing.match pattern
 703     end
 704     false
 705   end
 706 end