services/api/app/models/container.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 'whitelist_update'
   7 require 'safe_json'
   8 require 'update_priority'
   9
  10 class Container < ArvadosModel
  11   include ArvadosModelUpdates
  12   include HasUuid
  13   include KindAndEtag
  14   include CommonApiTemplate
  15   include WhitelistUpdate
  16   extend CurrentApiClient
  17   extend DbCurrentTime
  18   extend LogReuseInfo
  19
  20   serialize :environment, Hash
  21   serialize :mounts, Hash
  22   serialize :runtime_constraints, Hash
  23   serialize :command, Array
  24   serialize :scheduling_parameters, Hash
  25   serialize :secret_mounts, Hash
  26   serialize :runtime_status, Hash
  27
  28   before_validation :fill_field_defaults, :if => :new_record?
  29   before_validation :set_timestamps
  30   validates :command, :container_image, :output_path, :cwd, :priority, { presence: true }
  31   validates :priority, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
  32   validate :validate_runtime_status
  33   validate :validate_state_change
  34   validate :validate_change
  35   validate :validate_lock
  36   validate :validate_output
  37   after_validation :assign_auth
  38   before_save :sort_serialized_attrs
  39   before_save :update_secret_mounts_md5
  40   before_save :scrub_secrets
  41   before_save :clear_runtime_status_when_queued
  42   after_save :update_cr_logs
  43   after_save :handle_completed
  44   after_save :propagate_priority
  45   after_commit { UpdatePriority.run_update_thread }
  46
  47   has_many :container_requests, :foreign_key => :container_uuid, :class_name => 'ContainerRequest', :primary_key => :uuid
  48   belongs_to :auth, :class_name => 'ApiClientAuthorization', :foreign_key => :auth_uuid, :primary_key => :uuid
  49
  50   api_accessible :user, extend: :common do |t|
  51     t.add :command
  52     t.add :container_image
  53     t.add :cwd
  54     t.add :environment
  55     t.add :exit_code
  56     t.add :finished_at
  57     t.add :locked_by_uuid
  58     t.add :log
  59     t.add :mounts
  60     t.add :output
  61     t.add :output_path
  62     t.add :priority
  63     t.add :progress
  64     t.add :runtime_constraints
  65     t.add :runtime_status
  66     t.add :started_at
  67     t.add :state
  68     t.add :auth_uuid
  69     t.add :scheduling_parameters
  70   end
  71
  72   # Supported states for a container
  73   States =
  74     [
  75      (Queued = 'Queued'),
  76      (Locked = 'Locked'),
  77      (Running = 'Running'),
  78      (Complete = 'Complete'),
  79      (Cancelled = 'Cancelled')
  80     ]
  81
  82   State_transitions = {
  83     nil => [Queued],
  84     Queued => [Locked, Cancelled],
  85     Locked => [Queued, Running, Cancelled],
  86     Running => [Complete, Cancelled]
  87   }
  88
  89   def self.limit_index_columns_read
  90     ["mounts"]
  91   end
  92
  93   def self.full_text_searchable_columns
  94     super - ["secret_mounts", "secret_mounts_md5", "runtime_token"]
  95   end
  96
  97   def self.searchable_columns *args
  98     super - ["secret_mounts_md5", "runtime_token"]
  99   end
 100
 101   def logged_attributes
 102     super.except('secret_mounts', 'runtime_token')
 103   end
 104
 105   def state_transitions
 106     State_transitions
 107   end
 108
 109   # Container priority is the highest "computed priority" of any
 110   # matching request. The computed priority of a container-submitted
 111   # request is the priority of the submitting container. The computed
 112   # priority of a user-submitted request is a function of
 113   # user-assigned priority and request creation time.
 114   def update_priority!
 115     return if ![Queued, Locked, Running].include?(state)
 116     p = ContainerRequest.
 117         where('container_uuid=? and priority>0', uuid).
 118         includes(:requesting_container).
 119         lock(true).
 120         map do |cr|
 121       if cr.requesting_container
 122         cr.requesting_container.priority
 123       else
 124         (cr.priority << 50) - (cr.created_at.to_time.to_f * 1000).to_i
 125       end
 126     end.max || 0
 127     update_attributes!(priority: p)
 128   end
 129
 130   def propagate_priority
 131     return true unless priority_changed?
 132     act_as_system_user do
 133       # Update the priority of child container requests to match new
 134       # priority of the parent container (ignoring requests with no
 135       # container assigned, because their priority doesn't matter).
 136       ContainerRequest.
 137         where(requesting_container_uuid: self.uuid,
 138               state: ContainerRequest::Committed).
 139         where('container_uuid is not null').
 140         includes(:container).
 141         map(&:container).
 142         map(&:update_priority!)
 143     end
 144   end
 145
 146   # Create a new container (or find an existing one) to satisfy the
 147   # given container request.
 148   def self.resolve(req)
 149     if req.runtime_token.nil?
 150       runtime_user = if req.modified_by_user_uuid.nil?
 151                        current_user
 152                      else
 153                        User.find_by_uuid(req.modified_by_user_uuid)
 154                      end
 155       runtime_auth_scopes = ["all"]
 156     else
 157       auth = ApiClientAuthorization.validate(token: req.runtime_token)
 158       if auth.nil?
 159         raise ArgumentError.new "Invalid runtime token"
 160       end
 161       runtime_user = User.find_by_id(auth.user_id)
 162       runtime_auth_scopes = auth.scopes
 163     end
 164     c_attrs = act_as_user runtime_user do
 165       {
 166         command: req.command,
 167         cwd: req.cwd,
 168         environment: req.environment,
 169         output_path: req.output_path,
 170         container_image: resolve_container_image(req.container_image),
 171         mounts: resolve_mounts(req.mounts),
 172         runtime_constraints: resolve_runtime_constraints(req.runtime_constraints),
 173         scheduling_parameters: req.scheduling_parameters,
 174         secret_mounts: req.secret_mounts,
 175         runtime_token: req.runtime_token,
 176         runtime_user_uuid: runtime_user.uuid,
 177         runtime_auth_scopes: runtime_auth_scopes
 178       }
 179     end
 180     act_as_system_user do
 181       if req.use_existing && (reusable = find_reusable(c_attrs))
 182         reusable
 183       else
 184         Container.create!(c_attrs)
 185       end
 186     end
 187   end
 188
 189   # Return a runtime_constraints hash that complies with requested but
 190   # is suitable for saving in a container record, i.e., has specific
 191   # values instead of ranges.
 192   #
 193   # Doing this as a step separate from other resolutions, like "git
 194   # revision range to commit hash", makes sense only when there is no
 195   # opportunity to reuse an existing container (e.g., container reuse
 196   # is not implemented yet, or we have already found that no existing
 197   # containers are suitable).
 198   def self.resolve_runtime_constraints(runtime_constraints)
 199     rc = {}
 200     defaults = {
 201       'keep_cache_ram' =>
 202       Rails.configuration.container_default_keep_cache_ram,
 203     }
 204     defaults.merge(runtime_constraints).each do |k, v|
 205       if v.is_a? Array
 206         rc[k] = v[0]
 207       else
 208         rc[k] = v
 209       end
 210     end
 211     rc
 212   end
 213
 214   # Return a mounts hash suitable for a Container, i.e., with every
 215   # readonly collection UUID resolved to a PDH.
 216   def self.resolve_mounts(mounts)
 217     c_mounts = {}
 218     mounts.each do |k, mount|
 219       mount = mount.dup
 220       c_mounts[k] = mount
 221       if mount['kind'] != 'collection'
 222         next
 223       end
 224       if (uuid = mount.delete 'uuid')
 225         c = Collection.
 226           readable_by(current_user).
 227           where(uuid: uuid).
 228           select(:portable_data_hash).
 229           first
 230         if !c
 231           raise ArvadosModel::UnresolvableContainerError.new "cannot mount collection #{uuid.inspect}: not found"
 232         end
 233         if mount['portable_data_hash'].nil?
 234           # PDH not supplied by client
 235           mount['portable_data_hash'] = c.portable_data_hash
 236         elsif mount['portable_data_hash'] != c.portable_data_hash
 237           # UUID and PDH supplied by client, but they don't agree
 238           raise ArgumentError.new "cannot mount collection #{uuid.inspect}: current portable_data_hash #{c.portable_data_hash.inspect} does not match #{c['portable_data_hash'].inspect} in request"
 239         end
 240       end
 241     end
 242     return c_mounts
 243   end
 244
 245   # Return a container_image PDH suitable for a Container.
 246   def self.resolve_container_image(container_image)
 247     coll = Collection.for_latest_docker_image(container_image)
 248     if !coll
 249       raise ArvadosModel::UnresolvableContainerError.new "docker image #{container_image.inspect} not found"
 250     end
 251     coll.portable_data_hash
 252   end
 253
 254   def self.find_reusable(attrs)
 255     log_reuse_info { "starting with #{Container.all.count} container records in database" }
 256     candidates = Container.where_serialized(:command, attrs[:command], md5: true)
 257     log_reuse_info(candidates) { "after filtering on command #{attrs[:command].inspect}" }
 258
 259     candidates = candidates.where('cwd = ?', attrs[:cwd])
 260     log_reuse_info(candidates) { "after filtering on cwd #{attrs[:cwd].inspect}" }
 261
 262     candidates = candidates.where_serialized(:environment, attrs[:environment], md5: true)
 263     log_reuse_info(candidates) { "after filtering on environment #{attrs[:environment].inspect}" }
 264
 265     candidates = candidates.where('output_path = ?', attrs[:output_path])
 266     log_reuse_info(candidates) { "after filtering on output_path #{attrs[:output_path].inspect}" }
 267
 268     image = resolve_container_image(attrs[:container_image])
 269     candidates = candidates.where('container_image = ?', image)
 270     log_reuse_info(candidates) { "after filtering on container_image #{image.inspect} (resolved from #{attrs[:container_image].inspect})" }
 271
 272     candidates = candidates.where_serialized(:mounts, resolve_mounts(attrs[:mounts]), md5: true)
 273     log_reuse_info(candidates) { "after filtering on mounts #{attrs[:mounts].inspect}" }
 274
 275     secret_mounts_md5 = Digest::MD5.hexdigest(SafeJSON.dump(self.deep_sort_hash(attrs[:secret_mounts])))
 276     candidates = candidates.where('secret_mounts_md5 = ?', secret_mounts_md5)
 277     log_reuse_info(candidates) { "after filtering on secret_mounts_md5 #{secret_mounts_md5.inspect}" }
 278
 279     candidates = candidates.where_serialized(:runtime_constraints, resolve_runtime_constraints(attrs[:runtime_constraints]), md5: true)
 280     log_reuse_info(candidates) { "after filtering on runtime_constraints #{attrs[:runtime_constraints].inspect}" }
 281
 282     candidates = candidates.where('runtime_user_uuid = ? or (runtime_user_uuid is NULL and runtime_auth_scopes is NULL)',
 283                                   attrs[:runtime_user_uuid])
 284     log_reuse_info(candidates) { "after filtering on runtime_user_uuid #{attrs[:runtime_user_uuid].inspect}" }
 285
 286     candidates = candidates.where('runtime_auth_scopes = ? or (runtime_user_uuid is NULL and runtime_auth_scopes is NULL)',
 287                                   SafeJSON.dump(attrs[:runtime_auth_scopes]))
 288     log_reuse_info(candidates) { "after filtering on runtime_auth_scopes #{attrs[:runtime_auth_scopes].inspect}" }
 289
 290     log_reuse_info { "checking for state=Complete with readable output and log..." }
 291
 292     select_readable_pdh = Collection.
 293       readable_by(current_user).
 294       select(:portable_data_hash).
 295       to_sql
 296
 297     usable = candidates.where(state: Complete, exit_code: 0)
 298     log_reuse_info(usable) { "with state=Complete, exit_code=0" }
 299
 300     usable = usable.where("log IN (#{select_readable_pdh})")
 301     log_reuse_info(usable) { "with readable log" }
 302
 303     usable = usable.where("output IN (#{select_readable_pdh})")
 304     log_reuse_info(usable) { "with readable output" }
 305
 306     usable = usable.order('finished_at ASC').limit(1).first
 307     if usable
 308       log_reuse_info { "done, reusing container #{usable.uuid} with state=Complete" }
 309       return usable
 310     end
 311
 312     # Check for non-failing Running candidates and return the most likely to finish sooner.
 313     log_reuse_info { "checking for state=Running..." }
 314     running = candidates.where(state: Running).
 315               where("(runtime_status->'error') is null").
 316               order('progress desc, started_at asc').
 317               limit(1).first
 318     if running
 319       log_reuse_info { "done, reusing container #{running.uuid} with state=Running" }
 320       return running
 321     else
 322       log_reuse_info { "have no containers in Running state" }
 323     end
 324
 325     # Check for Locked or Queued ones and return the most likely to start first.
 326     locked_or_queued = candidates.
 327                        where("state IN (?)", [Locked, Queued]).
 328                        order('state asc, priority desc, created_at asc').
 329                        limit(1).first
 330     if locked_or_queued
 331       log_reuse_info { "done, reusing container #{locked_or_queued.uuid} with state=#{locked_or_queued.state}" }
 332       return locked_or_queued
 333     else
 334       log_reuse_info { "have no containers in Locked or Queued state" }
 335     end
 336
 337     log_reuse_info { "done, no reusable container found" }
 338     nil
 339   end
 340
 341   def check_lock_fail
 342     if self.state != Queued
 343       raise LockFailedError.new("cannot lock when #{self.state}")
 344     elsif self.priority <= 0
 345       raise LockFailedError.new("cannot lock when priority<=0")
 346     end
 347   end
 348
 349   def lock
 350     # Check invalid state transitions once before getting the lock
 351     # (because it's cheaper that way) and once after getting the lock
 352     # (because state might have changed while acquiring the lock).
 353     check_lock_fail
 354     transaction do
 355       reload
 356       check_lock_fail
 357       update_attributes!(state: Locked)
 358     end
 359   end
 360
 361   def check_unlock_fail
 362     if self.state != Locked
 363       raise InvalidStateTransitionError.new("cannot unlock when #{self.state}")
 364     elsif self.locked_by_uuid != current_api_client_authorization.uuid
 365       raise InvalidStateTransitionError.new("locked by a different token")
 366     end
 367   end
 368
 369   def unlock
 370     # Check invalid state transitions twice (see lock)
 371     check_unlock_fail
 372     transaction do
 373       reload(lock: 'FOR UPDATE')
 374       check_unlock_fail
 375       update_attributes!(state: Queued)
 376     end
 377   end
 378
 379   def self.readable_by(*users_list)
 380     # Load optional keyword arguments, if they exist.
 381     if users_list.last.is_a? Hash
 382       kwargs = users_list.pop
 383     else
 384       kwargs = {}
 385     end
 386     Container.where(ContainerRequest.readable_by(*users_list).where("containers.uuid = container_requests.container_uuid").exists)
 387   end
 388
 389   def final?
 390     [Complete, Cancelled].include?(self.state)
 391   end
 392
 393   def self.for_current_token
 394     _, _, _, container_uuid = Thread.current[:token].split('/')
 395     if container_uuid.nil?
 396       Container.where(auth_uuid: current_api_client_authorization.uuid)
 397     else
 398       Container.where('auth_uuid=? or (uuid=? and runtime_token=?)',
 399                       current_api_client_authorization.uuid,
 400                       container_uuid,
 401                       current_api_client_authorization.token)
 402     end
 403   end
 404
 405   protected
 406
 407   def fill_field_defaults
 408     self.state ||= Queued
 409     self.environment ||= {}
 410     self.runtime_constraints ||= {}
 411     self.mounts ||= {}
 412     self.cwd ||= "."
 413     self.priority ||= 0
 414     self.scheduling_parameters ||= {}
 415   end
 416
 417   def permission_to_create
 418     current_user.andand.is_admin
 419   end
 420
 421   def ensure_owner_uuid_is_permitted
 422     # validate_change ensures owner_uuid can't be changed at all --
 423     # except during create, which requires admin privileges. Checking
 424     # permission here would be superfluous.
 425     true
 426   end
 427
 428   def set_timestamps
 429     if self.state_changed? and self.state == Running
 430       self.started_at ||= db_current_time
 431     end
 432
 433     if self.state_changed? and [Complete, Cancelled].include? self.state
 434       self.finished_at ||= db_current_time
 435     end
 436   end
 437
 438   # Check that well-known runtime status keys have desired data types
 439   def validate_runtime_status
 440     [
 441       'error', 'errorDetail', 'warning', 'warningDetail', 'activity'
 442     ].each do |k|
 443       if self.runtime_status.andand.include?(k) && !self.runtime_status[k].is_a?(String)
 444         errors.add(:runtime_status, "'#{k}' value must be a string")
 445       end
 446     end
 447   end
 448
 449   def validate_change
 450     permitted = [:state]
 451     progress_attrs = [:progress, :runtime_status, :log, :output]
 452     final_attrs = [:exit_code, :finished_at]
 453
 454     if self.new_record?
 455       permitted.push(:owner_uuid, :command, :container_image, :cwd,
 456                      :environment, :mounts, :output_path, :priority,
 457                      :runtime_constraints, :scheduling_parameters,
 458                      :secret_mounts, :runtime_token,
 459                      :runtime_user_uuid, :runtime_auth_scopes)
 460     end
 461
 462     case self.state
 463     when Locked
 464       permitted.push :priority, :runtime_status, :log
 465
 466     when Queued
 467       permitted.push :priority
 468
 469     when Running
 470       permitted.push :priority, *progress_attrs
 471       if self.state_changed?
 472         permitted.push :started_at
 473       end
 474
 475     when Complete
 476       if self.state_was == Running
 477         permitted.push *final_attrs, *progress_attrs
 478       end
 479
 480     when Cancelled
 481       case self.state_was
 482       when Running
 483         permitted.push :finished_at, *progress_attrs
 484       when Queued, Locked
 485         permitted.push :finished_at, :log
 486       end
 487
 488     else
 489       # The state_transitions check will add an error message for this
 490       return false
 491     end
 492
 493     if current_api_client_authorization.andand.uuid.andand == self.auth_uuid
 494       # The contained process itself can update progress indicators,
 495       # but can't change priority etc.
 496       permitted = permitted & (progress_attrs + final_attrs + [:state] - [:log])
 497     elsif self.locked_by_uuid && self.locked_by_uuid != current_api_client_authorization.andand.uuid
 498       # When locked, progress fields cannot be updated by the wrong
 499       # dispatcher, even though it has admin privileges.
 500       permitted = permitted - progress_attrs
 501     end
 502     check_update_whitelist permitted
 503   end
 504
 505   def validate_lock
 506     if [Locked, Running].include? self.state
 507       # If the Container was already locked, locked_by_uuid must not
 508       # changes. Otherwise, the current auth gets the lock.
 509       need_lock = locked_by_uuid_was || current_api_client_authorization.andand.uuid
 510     else
 511       need_lock = nil
 512     end
 513
 514     # The caller can provide a new value for locked_by_uuid, but only
 515     # if it's exactly what we expect. This allows a caller to perform
 516     # an update like {"state":"Unlocked","locked_by_uuid":null}.
 517     if self.locked_by_uuid_changed?
 518       if self.locked_by_uuid != need_lock
 519         return errors.add :locked_by_uuid, "can only change to #{need_lock}"
 520       end
 521     end
 522     self.locked_by_uuid = need_lock
 523   end
 524
 525   def validate_output
 526     # Output must exist and be readable by the current user.  This is so
 527     # that a container cannot "claim" a collection that it doesn't otherwise
 528     # have access to just by setting the output field to the collection PDH.
 529     if output_changed?
 530       c = Collection.
 531             readable_by(current_user, {include_trash: true}).
 532             where(portable_data_hash: self.output).
 533             first
 534       if !c
 535         errors.add :output, "collection must exist and be readable by current user."
 536       end
 537     end
 538   end
 539
 540   def update_cr_logs
 541     # If self.final?, this update is superfluous: the final log/output
 542     # update will be done when handle_completed calls finalize! on
 543     # each requesting CR.
 544     return if self.final? || !self.log_changed?
 545     leave_modified_by_user_alone do
 546       ContainerRequest.where(container_uuid: self.uuid).each do |cr|
 547         cr.update_collections(container: self, collections: ['log'])
 548         cr.save!
 549       end
 550     end
 551   end
 552
 553   def assign_auth
 554     if self.auth_uuid_changed?
 555          return errors.add :auth_uuid, 'is readonly'
 556     end
 557     if not [Locked, Running].include? self.state
 558       # don't need one
 559       self.auth.andand.update_attributes(expires_at: db_current_time)
 560       self.auth = nil
 561       return
 562     elsif self.auth
 563       # already have one
 564       return
 565     end
 566     if self.runtime_token.nil?
 567       if self.runtime_user_uuid.nil?
 568         # legacy behavior, we don't have a runtime_user_uuid so get
 569         # the user from the highest priority container request, needed
 570         # when performing an upgrade and there are queued containers,
 571         # and some tests.
 572         cr = ContainerRequest.
 573                where('container_uuid=? and priority>0', self.uuid).
 574                order('priority desc').
 575                first
 576         if !cr
 577           return errors.add :auth_uuid, "cannot be assigned because priority <= 0"
 578         end
 579         self.runtime_user_uuid = cr.modified_by_user_uuid
 580         self.runtime_auth_scopes = ["all"]
 581       end
 582
 583       # generate a new token
 584       self.auth = ApiClientAuthorization.
 585                     create!(user_id: User.find_by_uuid(self.runtime_user_uuid).id,
 586                             api_client_id: 0,
 587                             scopes: self.runtime_auth_scopes)
 588     end
 589   end
 590
 591   def sort_serialized_attrs
 592     if self.environment_changed?
 593       self.environment = self.class.deep_sort_hash(self.environment)
 594     end
 595     if self.mounts_changed?
 596       self.mounts = self.class.deep_sort_hash(self.mounts)
 597     end
 598     if self.runtime_constraints_changed?
 599       self.runtime_constraints = self.class.deep_sort_hash(self.runtime_constraints)
 600     end
 601     if self.scheduling_parameters_changed?
 602       self.scheduling_parameters = self.class.deep_sort_hash(self.scheduling_parameters)
 603     end
 604   end
 605
 606   def update_secret_mounts_md5
 607     if self.secret_mounts_changed?
 608       self.secret_mounts_md5 = Digest::MD5.hexdigest(
 609         SafeJSON.dump(self.class.deep_sort_hash(self.secret_mounts)))
 610     end
 611   end
 612
 613   def scrub_secrets
 614     # this runs after update_secret_mounts_md5, so the
 615     # secret_mounts_md5 will still reflect the secrets that are being
 616     # scrubbed here.
 617     if self.state_changed? && self.final?
 618       self.secret_mounts = {}
 619       self.runtime_token = nil
 620     end
 621   end
 622
 623   def clear_runtime_status_when_queued
 624     # Avoid leaking status messages between different dispatch attempts
 625     if self.state_was == Locked && self.state == Queued
 626       self.runtime_status = {}
 627     end
 628   end
 629
 630   def handle_completed
 631     # This container is finished so finalize any associated container requests
 632     # that are associated with this container.
 633     if self.state_changed? and self.final?
 634       act_as_system_user do
 635
 636         if self.state == Cancelled
 637           retryable_requests = ContainerRequest.where("container_uuid = ? and priority > 0 and state = 'Committed' and container_count < container_count_max", uuid)
 638         else
 639           retryable_requests = []
 640         end
 641
 642         if retryable_requests.any?
 643           c_attrs = {
 644             command: self.command,
 645             cwd: self.cwd,
 646             environment: self.environment,
 647             output_path: self.output_path,
 648             container_image: self.container_image,
 649             mounts: self.mounts,
 650             runtime_constraints: self.runtime_constraints,
 651             scheduling_parameters: self.scheduling_parameters,
 652             secret_mounts: self.secret_mounts_was,
 653             runtime_token: self.runtime_token_was,
 654             runtime_user_uuid: self.runtime_user_uuid,
 655             runtime_auth_scopes: self.runtime_auth_scopes
 656           }
 657           c = Container.create! c_attrs
 658           retryable_requests.each do |cr|
 659             cr.with_lock do
 660               leave_modified_by_user_alone do
 661                 # Use row locking because this increments container_count
 662                 cr.container_uuid = c.uuid
 663                 cr.save!
 664               end
 665             end
 666           end
 667         end
 668
 669         # Notify container requests associated with this container
 670         ContainerRequest.where(container_uuid: uuid,
 671                                state: ContainerRequest::Committed).each do |cr|
 672           leave_modified_by_user_alone do
 673             cr.finalize!
 674           end
 675         end
 676
 677         # Cancel outstanding container requests made by this container.
 678         ContainerRequest.
 679           includes(:container).
 680           where(requesting_container_uuid: uuid,
 681                 state: ContainerRequest::Committed).each do |cr|
 682           leave_modified_by_user_alone do
 683             cr.update_attributes!(priority: 0)
 684             cr.container.reload
 685             if cr.container.state == Container::Queued || cr.container.state == Container::Locked
 686               # If the child container hasn't started yet, finalize the
 687               # child CR now instead of leaving it "on hold", i.e.,
 688               # Queued with priority 0.  (OTOH, if the child is already
 689               # running, leave it alone so it can get cancelled the
 690               # usual way, get a copy of the log collection, etc.)
 691               cr.update_attributes!(state: ContainerRequest::Final)
 692             end
 693           end
 694         end
 695       end
 696     end
 697   end
 698 end