18842: Fix tests
[arvados.git] / 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   # Posgresql JSONB columns should NOT be declared as serialized, Rails 5
21   # already know how to properly treat them.
22   attribute :secret_mounts, :jsonbHash, default: {}
23   attribute :runtime_status, :jsonbHash, default: {}
24   attribute :runtime_auth_scopes, :jsonbArray, default: []
25   attribute :output_storage_classes, :jsonbArray, default: lambda { Rails.configuration.DefaultStorageClasses }
26   attribute :output_properties, :jsonbHash, default: {}
27
28   serialize :environment, Hash
29   serialize :mounts, Hash
30   serialize :runtime_constraints, Hash
31   serialize :command, Array
32   serialize :scheduling_parameters, Hash
33
34   after_find :fill_container_defaults_after_find
35   before_validation :fill_field_defaults, :if => :new_record?
36   before_validation :set_timestamps
37   before_validation :check_lock
38   before_validation :check_unlock
39   validates :command, :container_image, :output_path, :cwd, :priority, { presence: true }
40   validates :priority, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
41   validate :validate_runtime_status
42   validate :validate_state_change
43   validate :validate_change
44   validate :validate_lock
45   validate :validate_output
46   after_validation :assign_auth
47   before_save :sort_serialized_attrs
48   before_save :update_secret_mounts_md5
49   before_save :scrub_secrets
50   before_save :clear_runtime_status_when_queued
51   after_save :update_cr_logs
52   after_save :handle_completed
53   after_save :propagate_priority
54   after_commit { UpdatePriority.run_update_thread }
55
56   has_many :container_requests, :foreign_key => :container_uuid, :class_name => 'ContainerRequest', :primary_key => :uuid
57   belongs_to :auth, :class_name => 'ApiClientAuthorization', :foreign_key => :auth_uuid, :primary_key => :uuid
58
59   api_accessible :user, extend: :common do |t|
60     t.add :command
61     t.add :container_image
62     t.add :cwd
63     t.add :environment
64     t.add :exit_code
65     t.add :finished_at
66     t.add :locked_by_uuid
67     t.add :log
68     t.add :mounts
69     t.add :output
70     t.add :output_path
71     t.add :priority
72     t.add :progress
73     t.add :runtime_constraints
74     t.add :runtime_status
75     t.add :started_at
76     t.add :state
77     t.add :auth_uuid
78     t.add :scheduling_parameters
79     t.add :runtime_user_uuid
80     t.add :runtime_auth_scopes
81     t.add :lock_count
82     t.add :gateway_address
83     t.add :interactive_session_started
84     t.add :output_storage_classes
85     t.add :output_properties
86     t.add :cost
87     t.add :subrequests_cost
88   end
89
90   # Supported states for a container
91   States =
92     [
93      (Queued = 'Queued'),
94      (Locked = 'Locked'),
95      (Running = 'Running'),
96      (Complete = 'Complete'),
97      (Cancelled = 'Cancelled')
98     ]
99
100   State_transitions = {
101     nil => [Queued],
102     Queued => [Locked, Cancelled],
103     Locked => [Queued, Running, Cancelled],
104     Running => [Complete, Cancelled],
105     Complete => [Cancelled]
106   }
107
108   def self.limit_index_columns_read
109     ["mounts"]
110   end
111
112   def self.full_text_searchable_columns
113     super - ["secret_mounts", "secret_mounts_md5", "runtime_token", "gateway_address", "output_storage_classes"]
114   end
115
116   def self.searchable_columns *args
117     super - ["secret_mounts_md5", "runtime_token", "gateway_address", "output_storage_classes"]
118   end
119
120   def logged_attributes
121     super.except('secret_mounts', 'runtime_token')
122   end
123
124   def state_transitions
125     State_transitions
126   end
127
128   # Container priority is the highest "computed priority" of any
129   # matching request. The computed priority of a container-submitted
130   # request is the priority of the submitting container. The computed
131   # priority of a user-submitted request is a function of
132   # user-assigned priority and request creation time.
133   def update_priority!
134     return if ![Queued, Locked, Running].include?(state)
135     p = ContainerRequest.
136         where('container_uuid=? and priority>0', uuid).
137         includes(:requesting_container).
138         lock(true).
139         map do |cr|
140       if cr.requesting_container
141         cr.requesting_container.priority
142       else
143         (cr.priority << 50) - (cr.created_at.to_time.to_f * 1000).to_i
144       end
145     end.max || 0
146     update_attributes!(priority: p)
147   end
148
149   def propagate_priority
150     return true unless saved_change_to_priority?
151     act_as_system_user do
152       # Update the priority of child container requests to match new
153       # priority of the parent container (ignoring requests with no
154       # container assigned, because their priority doesn't matter).
155       ContainerRequest.
156         where(requesting_container_uuid: self.uuid,
157               state: ContainerRequest::Committed).
158         where('container_uuid is not null').
159         includes(:container).
160         map(&:container).
161         map(&:update_priority!)
162     end
163   end
164
165   # Create a new container (or find an existing one) to satisfy the
166   # given container request.
167   def self.resolve(req)
168     if req.runtime_token.nil?
169       runtime_user = if req.modified_by_user_uuid.nil?
170                        current_user
171                      else
172                        User.find_by_uuid(req.modified_by_user_uuid)
173                      end
174       runtime_auth_scopes = ["all"]
175     else
176       auth = ApiClientAuthorization.validate(token: req.runtime_token)
177       if auth.nil?
178         raise ArgumentError.new "Invalid runtime token"
179       end
180       runtime_user = User.find_by_id(auth.user_id)
181       runtime_auth_scopes = auth.scopes
182     end
183     c_attrs = act_as_user runtime_user do
184       {
185         command: req.command,
186         cwd: req.cwd,
187         environment: req.environment,
188         output_path: req.output_path,
189         container_image: resolve_container_image(req.container_image),
190         mounts: resolve_mounts(req.mounts),
191         runtime_constraints: resolve_runtime_constraints(req.runtime_constraints),
192         scheduling_parameters: req.scheduling_parameters,
193         secret_mounts: req.secret_mounts,
194         runtime_token: req.runtime_token,
195         runtime_user_uuid: runtime_user.uuid,
196         runtime_auth_scopes: runtime_auth_scopes,
197         output_storage_classes: req.output_storage_classes,
198       }
199     end
200     act_as_system_user do
201       if req.use_existing && (reusable = find_reusable(c_attrs))
202         reusable
203       else
204         Container.create!(c_attrs)
205       end
206     end
207   end
208
209   # Return a runtime_constraints hash that complies with requested but
210   # is suitable for saving in a container record, i.e., has specific
211   # values instead of ranges.
212   #
213   # Doing this as a step separate from other resolutions, like "git
214   # revision range to commit hash", makes sense only when there is no
215   # opportunity to reuse an existing container (e.g., container reuse
216   # is not implemented yet, or we have already found that no existing
217   # containers are suitable).
218   def self.resolve_runtime_constraints(runtime_constraints)
219     rc = {}
220     runtime_constraints.each do |k, v|
221       if v.is_a? Array
222         rc[k] = v[0]
223       else
224         rc[k] = v
225       end
226     end
227     if rc['keep_cache_ram'] == 0
228       rc['keep_cache_ram'] = Rails.configuration.Containers.DefaultKeepCacheRAM
229     end
230     if rc['keep_cache_disk'] == 0 and rc['keep_cache_ram'] == 0
231       # Only set if keep_cache_ram isn't set.
232       rc['keep_cache_disk'] = Rails.configuration.Containers.DefaultKeepCacheDisk
233     end
234     rc
235   end
236
237   # Return a mounts hash suitable for a Container, i.e., with every
238   # readonly collection UUID resolved to a PDH.
239   def self.resolve_mounts(mounts)
240     c_mounts = {}
241     mounts.each do |k, mount|
242       mount = mount.dup
243       c_mounts[k] = mount
244       if mount['kind'] != 'collection'
245         next
246       end
247
248       uuid = mount.delete 'uuid'
249
250       if mount['portable_data_hash'].nil? and !uuid.nil?
251         # PDH not supplied, try by UUID
252         c = Collection.
253           readable_by(current_user).
254           where(uuid: uuid).
255           select(:portable_data_hash).
256           first
257         if !c
258           raise ArvadosModel::UnresolvableContainerError.new "cannot mount collection #{uuid.inspect}: not found"
259         end
260         mount['portable_data_hash'] = c.portable_data_hash
261       end
262     end
263     return c_mounts
264   end
265
266   # Return a container_image PDH suitable for a Container.
267   def self.resolve_container_image(container_image)
268     coll = Collection.for_latest_docker_image(container_image)
269     if !coll
270       raise ArvadosModel::UnresolvableContainerError.new "docker image #{container_image.inspect} not found"
271     end
272     coll.portable_data_hash
273   end
274
275   def self.find_reusable(attrs)
276     log_reuse_info { "starting with #{Container.all.count} container records in database" }
277     candidates = Container.where_serialized(:command, attrs[:command], md5: true)
278     log_reuse_info(candidates) { "after filtering on command #{attrs[:command].inspect}" }
279
280     candidates = candidates.where('cwd = ?', attrs[:cwd])
281     log_reuse_info(candidates) { "after filtering on cwd #{attrs[:cwd].inspect}" }
282
283     candidates = candidates.where_serialized(:environment, attrs[:environment], md5: true)
284     log_reuse_info(candidates) { "after filtering on environment #{attrs[:environment].inspect}" }
285
286     candidates = candidates.where('output_path = ?', attrs[:output_path])
287     log_reuse_info(candidates) { "after filtering on output_path #{attrs[:output_path].inspect}" }
288
289     image = resolve_container_image(attrs[:container_image])
290     candidates = candidates.where('container_image = ?', image)
291     log_reuse_info(candidates) { "after filtering on container_image #{image.inspect} (resolved from #{attrs[:container_image].inspect})" }
292
293     candidates = candidates.where_serialized(:mounts, resolve_mounts(attrs[:mounts]), md5: true)
294     log_reuse_info(candidates) { "after filtering on mounts #{attrs[:mounts].inspect}" }
295
296     secret_mounts_md5 = Digest::MD5.hexdigest(SafeJSON.dump(self.deep_sort_hash(attrs[:secret_mounts])))
297     candidates = candidates.where('secret_mounts_md5 = ?', secret_mounts_md5)
298     log_reuse_info(candidates) { "after filtering on secret_mounts_md5 #{secret_mounts_md5.inspect}" }
299
300     if attrs[:runtime_constraints]['cuda'].nil?
301       attrs[:runtime_constraints]['cuda'] = {
302         'device_count' => 0,
303         'driver_version' => '',
304         'hardware_capability' => '',
305       }
306     end
307     resolved_runtime_constraints = [resolve_runtime_constraints(attrs[:runtime_constraints])]
308     if resolved_runtime_constraints[0]['cuda']['device_count'] == 0
309       # If no CUDA requested, extend search to include older container
310       # records that don't have a 'cuda' section in runtime_constraints
311       resolved_runtime_constraints << resolved_runtime_constraints[0].except('cuda')
312     end
313     if resolved_runtime_constraints[0]['keep_cache_disk'] == 0
314       # If no disk cache requested, extend search to include older container
315       # records that don't have a 'keep_cache_disk' field in runtime_constraints
316       if resolved_runtime_constraints.length == 2
317         # exclude the one that also excludes CUDA
318         resolved_runtime_constraints << resolved_runtime_constraints[1].except('keep_cache_disk')
319       end
320       resolved_runtime_constraints << resolved_runtime_constraints[0].except('keep_cache_disk')
321     end
322
323     candidates = candidates.where_serialized(:runtime_constraints, resolved_runtime_constraints, md5: true, multivalue: true)
324     log_reuse_info(candidates) { "after filtering on runtime_constraints #{attrs[:runtime_constraints].inspect}" }
325
326     log_reuse_info { "checking for state=Complete with readable output and log..." }
327
328     select_readable_pdh = Collection.
329       readable_by(current_user).
330       select(:portable_data_hash).
331       to_sql
332
333     usable = candidates.where(state: Complete, exit_code: 0)
334     log_reuse_info(usable) { "with state=Complete, exit_code=0" }
335
336     usable = usable.where("log IN (#{select_readable_pdh})")
337     log_reuse_info(usable) { "with readable log" }
338
339     usable = usable.where("output IN (#{select_readable_pdh})")
340     log_reuse_info(usable) { "with readable output" }
341
342     usable = usable.order('finished_at ASC').limit(1).first
343     if usable
344       log_reuse_info { "done, reusing container #{usable.uuid} with state=Complete" }
345       return usable
346     end
347
348     # Check for non-failing Running candidates and return the most likely to finish sooner.
349     log_reuse_info { "checking for state=Running..." }
350     running = candidates.where(state: Running).
351               where("(runtime_status->'error') is null").
352               order('progress desc, started_at asc').
353               limit(1).first
354     if running
355       log_reuse_info { "done, reusing container #{running.uuid} with state=Running" }
356       return running
357     else
358       log_reuse_info { "have no containers in Running state" }
359     end
360
361     # Check for Locked or Queued ones and return the most likely to start first.
362     locked_or_queued = candidates.
363                        where("state IN (?)", [Locked, Queued]).
364                        order('state asc, priority desc, created_at asc').
365                        limit(1).first
366     if locked_or_queued
367       log_reuse_info { "done, reusing container #{locked_or_queued.uuid} with state=#{locked_or_queued.state}" }
368       return locked_or_queued
369     else
370       log_reuse_info { "have no containers in Locked or Queued state" }
371     end
372
373     log_reuse_info { "done, no reusable container found" }
374     nil
375   end
376
377   def lock
378     self.with_lock do
379       if self.state != Queued
380         raise LockFailedError.new("cannot lock when #{self.state}")
381       end
382       self.update_attributes!(state: Locked)
383     end
384   end
385
386   def check_lock
387     if state_was == Queued and state == Locked
388       if self.priority <= 0
389         raise LockFailedError.new("cannot lock when priority<=0")
390       end
391       self.lock_count = self.lock_count+1
392     end
393   end
394
395   def unlock
396     self.with_lock do
397       if self.state != Locked
398         raise InvalidStateTransitionError.new("cannot unlock when #{self.state}")
399       end
400       self.update_attributes!(state: Queued)
401     end
402   end
403
404   def check_unlock
405     if state_was == Locked and state == Queued
406       if self.locked_by_uuid != current_api_client_authorization.uuid
407         raise ArvadosModel::PermissionDeniedError.new("locked by a different token")
408       end
409       if self.lock_count >= Rails.configuration.Containers.MaxDispatchAttempts
410         self.state = Cancelled
411         self.runtime_status = {error: "Failed to start container.  Cancelled after exceeding 'Containers.MaxDispatchAttempts' (lock_count=#{self.lock_count})"}
412       end
413     end
414   end
415
416   def self.readable_by(*users_list)
417     # Load optional keyword arguments, if they exist.
418     if users_list.last.is_a? Hash
419       kwargs = users_list.pop
420     else
421       kwargs = {}
422     end
423     if users_list.select { |u| u.is_admin }.any?
424       return super
425     end
426     Container.where(ContainerRequest.readable_by(*users_list).where("containers.uuid = container_requests.container_uuid").arel.exists)
427   end
428
429   def final?
430     [Complete, Cancelled].include?(self.state)
431   end
432
433   def self.for_current_token
434     return if !current_api_client_authorization
435     _, _, _, container_uuid = Thread.current[:token].split('/')
436     if container_uuid.nil?
437       Container.where(auth_uuid: current_api_client_authorization.uuid).first
438     else
439       Container.where('auth_uuid=? or (uuid=? and runtime_token=?)',
440                       current_api_client_authorization.uuid,
441                       container_uuid,
442                       current_api_client_authorization.token).first
443     end
444   end
445
446   protected
447
448   def fill_field_defaults
449     self.state ||= Queued
450     self.environment ||= {}
451     self.runtime_constraints ||= {}
452     self.mounts ||= {}
453     self.cwd ||= "."
454     self.priority ||= 0
455     self.scheduling_parameters ||= {}
456   end
457
458   def permission_to_create
459     current_user.andand.is_admin
460   end
461
462   def permission_to_destroy
463     current_user.andand.is_admin
464   end
465
466   def ensure_owner_uuid_is_permitted
467     # validate_change ensures owner_uuid can't be changed at all --
468     # except during create, which requires admin privileges. Checking
469     # permission here would be superfluous.
470     true
471   end
472
473   def set_timestamps
474     if self.state_changed? and self.state == Running
475       self.started_at ||= db_current_time
476     end
477
478     if self.state_changed? and [Complete, Cancelled].include? self.state
479       self.finished_at ||= db_current_time
480     end
481   end
482
483   # Check that well-known runtime status keys have desired data types
484   def validate_runtime_status
485     [
486       'error', 'errorDetail', 'warning', 'warningDetail', 'activity'
487     ].each do |k|
488       if self.runtime_status.andand.include?(k) && !self.runtime_status[k].is_a?(String)
489         errors.add(:runtime_status, "'#{k}' value must be a string")
490       end
491     end
492   end
493
494   def validate_change
495     permitted = [:state]
496     final_attrs = [:finished_at]
497     progress_attrs = [:progress, :runtime_status, :subrequests_cost, :cost,
498                       :log, :output, :output_properties, :exit_code]
499
500     if self.new_record?
501       permitted.push(:owner_uuid, :command, :container_image, :cwd,
502                      :environment, :mounts, :output_path, :priority,
503                      :runtime_constraints, :scheduling_parameters,
504                      :secret_mounts, :runtime_token,
505                      :runtime_user_uuid, :runtime_auth_scopes,
506                      :output_storage_classes)
507     end
508
509     case self.state
510     when Locked
511       permitted.push :priority, :runtime_status, :log, :lock_count
512
513     when Queued
514       permitted.push :priority
515
516     when Running
517       permitted.push :priority, :output_properties, :gateway_address, *progress_attrs
518       if self.state_changed?
519         permitted.push :started_at
520       end
521       if !self.interactive_session_started_was
522         permitted.push :interactive_session_started
523       end
524
525     when Complete
526       if self.state_was == Running
527         permitted.push *final_attrs, *progress_attrs
528       end
529
530     when Cancelled
531       case self.state_was
532       when Running
533         permitted.push :finished_at, *progress_attrs
534       when Queued, Locked
535         permitted.push :finished_at, :log, :runtime_status, :cost
536       end
537
538     else
539       # The state_transitions check will add an error message for this
540       return false
541     end
542
543     if self.state_was == Running &&
544        !current_api_client_authorization.nil? &&
545        (current_api_client_authorization.uuid == self.auth_uuid ||
546         current_api_client_authorization.token == self.runtime_token)
547       # The contained process itself can write final attrs but can't
548       # change priority or log.
549       permitted.push *final_attrs
550       permitted = permitted - [:log, :priority]
551     elsif !current_user.andand.is_admin
552       raise PermissionDeniedError
553     elsif self.locked_by_uuid && self.locked_by_uuid != current_api_client_authorization.andand.uuid
554       # When locked, progress fields cannot be updated by the wrong
555       # dispatcher, even though it has admin privileges.
556       permitted = permitted - progress_attrs
557     end
558     check_update_whitelist permitted
559   end
560
561   def validate_lock
562     if [Locked, Running].include? self.state
563       # If the Container was already locked, locked_by_uuid must not
564       # changes. Otherwise, the current auth gets the lock.
565       need_lock = locked_by_uuid_was || current_api_client_authorization.andand.uuid
566     else
567       need_lock = nil
568     end
569
570     # The caller can provide a new value for locked_by_uuid, but only
571     # if it's exactly what we expect. This allows a caller to perform
572     # an update like {"state":"Unlocked","locked_by_uuid":null}.
573     if self.locked_by_uuid_changed?
574       if self.locked_by_uuid != need_lock
575         return errors.add :locked_by_uuid, "can only change to #{need_lock}"
576       end
577     end
578     self.locked_by_uuid = need_lock
579   end
580
581   def validate_output
582     # Output must exist and be readable by the current user.  This is so
583     # that a container cannot "claim" a collection that it doesn't otherwise
584     # have access to just by setting the output field to the collection PDH.
585     if output_changed?
586       c = Collection.
587             readable_by(current_user, {include_trash: true}).
588             where(portable_data_hash: self.output).
589             first
590       if !c
591         errors.add :output, "collection must exist and be readable by current user."
592       end
593     end
594   end
595
596   def update_cr_logs
597     # If self.final?, this update is superfluous: the final log/output
598     # update will be done when handle_completed calls finalize! on
599     # each requesting CR.
600     return if self.final? || !saved_change_to_log?
601     leave_modified_by_user_alone do
602       ContainerRequest.where(container_uuid: self.uuid).each do |cr|
603         cr.update_collections(container: self, collections: ['log'])
604         cr.save!
605       end
606     end
607   end
608
609   def assign_auth
610     if self.auth_uuid_changed?
611          return errors.add :auth_uuid, 'is readonly'
612     end
613     if not [Locked, Running].include? self.state
614       # Don't need one. If auth already exists, expire it.
615       #
616       # We use db_transaction_time here (not db_current_time) to
617       # ensure the token doesn't validate later in the same
618       # transaction (e.g., in a test case) by satisfying expires_at >
619       # transaction timestamp.
620       self.auth.andand.update_attributes(expires_at: db_transaction_time)
621       self.auth = nil
622       return
623     elsif self.auth
624       # already have one
625       return
626     end
627     if self.runtime_token.nil?
628       if self.runtime_user_uuid.nil?
629         # legacy behavior, we don't have a runtime_user_uuid so get
630         # the user from the highest priority container request, needed
631         # when performing an upgrade and there are queued containers,
632         # and some tests.
633         cr = ContainerRequest.
634                where('container_uuid=? and priority>0', self.uuid).
635                order('priority desc').
636                first
637         if !cr
638           return errors.add :auth_uuid, "cannot be assigned because priority <= 0"
639         end
640         self.runtime_user_uuid = cr.modified_by_user_uuid
641         self.runtime_auth_scopes = ["all"]
642       end
643
644       # Generate a new token. This runs with admin credentials as it's done by a
645       # dispatcher user, so expires_at isn't enforced by API.MaxTokenLifetime.
646       self.auth = ApiClientAuthorization.
647                     create!(user_id: User.find_by_uuid(self.runtime_user_uuid).id,
648                             api_client_id: 0,
649                             scopes: self.runtime_auth_scopes)
650     end
651   end
652
653   def sort_serialized_attrs
654     if self.environment_changed?
655       self.environment = self.class.deep_sort_hash(self.environment)
656     end
657     if self.mounts_changed?
658       self.mounts = self.class.deep_sort_hash(self.mounts)
659     end
660     if self.runtime_constraints_changed?
661       self.runtime_constraints = self.class.deep_sort_hash(self.runtime_constraints)
662     end
663     if self.scheduling_parameters_changed?
664       self.scheduling_parameters = self.class.deep_sort_hash(self.scheduling_parameters)
665     end
666     if self.runtime_auth_scopes_changed?
667       self.runtime_auth_scopes = self.runtime_auth_scopes.sort
668     end
669   end
670
671   def update_secret_mounts_md5
672     if self.secret_mounts_changed?
673       self.secret_mounts_md5 = Digest::MD5.hexdigest(
674         SafeJSON.dump(self.class.deep_sort_hash(self.secret_mounts)))
675     end
676   end
677
678   def scrub_secrets
679     # this runs after update_secret_mounts_md5, so the
680     # secret_mounts_md5 will still reflect the secrets that are being
681     # scrubbed here.
682     if self.state_changed? && self.final?
683       self.secret_mounts = {}
684       self.runtime_token = nil
685     end
686   end
687
688   def clear_runtime_status_when_queued
689     # Avoid leaking status messages between different dispatch attempts
690     if self.state_was == Locked && self.state == Queued
691       self.runtime_status = {}
692     end
693   end
694
695   def handle_completed
696     # This container is finished so finalize any associated container requests
697     # that are associated with this container.
698     if saved_change_to_state? and self.final?
699       # These get wiped out by with_lock (which reloads the record),
700       # so record them now in case we need to schedule a retry.
701       prev_secret_mounts = secret_mounts_before_last_save
702       prev_runtime_token = runtime_token_before_last_save
703
704       # Need to take a lock on the container to ensure that any
705       # concurrent container requests that might try to reuse this
706       # container will block until the container completion
707       # transaction finishes.  This ensure that concurrent container
708       # requests that try to reuse this container are finalized (on
709       # Complete) or don't reuse it (on Cancelled).
710       self.with_lock do
711         act_as_system_user do
712           if self.state == Cancelled
713             retryable_requests = ContainerRequest.where("container_uuid = ? and priority > 0 and state = 'Committed' and container_count < container_count_max", uuid)
714           else
715             retryable_requests = []
716           end
717
718           if retryable_requests.any?
719             c_attrs = {
720               command: self.command,
721               cwd: self.cwd,
722               environment: self.environment,
723               output_path: self.output_path,
724               container_image: self.container_image,
725               mounts: self.mounts,
726               runtime_constraints: self.runtime_constraints,
727               scheduling_parameters: self.scheduling_parameters,
728               secret_mounts: prev_secret_mounts,
729               runtime_token: prev_runtime_token,
730               runtime_user_uuid: self.runtime_user_uuid,
731               runtime_auth_scopes: self.runtime_auth_scopes
732             }
733             c = Container.create! c_attrs
734             retryable_requests.each do |cr|
735               cr.with_lock do
736                 leave_modified_by_user_alone do
737                   # Use row locking because this increments container_count
738                   cr.cumulative_cost += self.cost + self.subrequests_cost
739                   cr.container_uuid = c.uuid
740                   cr.save!
741                 end
742               end
743             end
744           end
745
746           # Notify container requests associated with this container
747           ContainerRequest.where(container_uuid: uuid,
748                                  state: ContainerRequest::Committed).each do |cr|
749             leave_modified_by_user_alone do
750               cr.finalize!
751             end
752           end
753
754           # Cancel outstanding container requests made by this container.
755           ContainerRequest.
756             includes(:container).
757             where(requesting_container_uuid: uuid,
758                   state: ContainerRequest::Committed).each do |cr|
759             leave_modified_by_user_alone do
760               cr.update_attributes!(priority: 0)
761               cr.container.reload
762               if cr.container.state == Container::Queued || cr.container.state == Container::Locked
763                 # If the child container hasn't started yet, finalize the
764                 # child CR now instead of leaving it "on hold", i.e.,
765                 # Queued with priority 0.  (OTOH, if the child is already
766                 # running, leave it alone so it can get cancelled the
767                 # usual way, get a copy of the log collection, etc.)
768                 cr.update_attributes!(state: ContainerRequest::Final)
769               end
770             end
771           end
772         end
773       end
774     end
775   end
776 end