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