Remove delayed_job dependecy. Lock jobs.

- Remove delayed_job dependecy completely from Gemfile.
- Lock jobs during migration from delayed_jobs to good_jobs using SELECT FOR UPDATE.
  It means that potentially not shut down DJ worker will not be able to
  pick them up for performing during the migration process. After
  migration has been finished the jobs in question will be in
  good_jobs table and delayed_jobs table will be removed. So,
  duplicate execution should not happen.

Gemfile

@@ -124,7 +124,6 @@ gem 'multi_json', '~> 1.15.0'
 gem 'oj', '~> 3.16.0'
 
 gem 'daemons'
-gem 'delayed_job', require: false # only needed for ActiveJob::QueueAdapters::DelayedJobAdapter::JobWrapper to be available in db/migrate/20240227154544_remove_delayed_jobs.rb
 gem 'good_job', '~> 3.26.1' # update should be done manually in sync with saas-openproject version.
 
 gem 'rack-protection', '~> 3.2.0'

Gemfile.lock

@@ -445,8 +445,6 @@ GEM
     deckar01-task_list (2.3.4)
       html-pipeline (~> 2.0)
     declarative (0.0.20)
-    delayed_job (4.1.11)
-      activesupport (>= 3.0, < 8.0)
     descendants_tracker (0.0.4)
       thread_safe (~> 0.3, >= 0.3.1)
     diff-lcs (1.5.1)
@@ -1162,7 +1160,6 @@ DEPENDENCIES
   date_validator (~> 0.12.0)
   debug
   deckar01-task_list (~> 2.3.1)
-  delayed_job
   disposable (~> 0.6.2)
   doorkeeper (~> 5.6.6)
   dotenv-rails

db/migrate/20240227154544_remove_delayed_jobs.rb

@@ -27,19 +27,32 @@
 #++
 
 class RemoveDelayedJobs < ActiveRecord::Migration[7.1]
+  # it is needed, because ActiveJob::QueueAdapters::DelayedJobAdapter::JobWrapper
+  # can not be used without required delayed_job
+  # See https://github.com/rails/rails/blob/6f0d1ad14b92b9f5906e44740fce8b4f1c7075dc/activejob/lib/active_job/queue_adapters/delayed_job_adapter.rb
+  class JobWrapperDeserializationMock
+    attr_accessor :job_data
+
+    def initialize(job_data)
+      @job_data = job_data
+    end
+  end
+
   def change
     reversible do |direction|
       direction.up do
         tuples = execute <<~SQL
           select * from delayed_jobs
-          where locked_by is null -- not in progress
-          and handler NOT LIKE '%job_class: Storages::ManageNextcloudIntegrationEventsJob%' -- no need to migrate. It will be run later with cron.
-          and cron is null; -- not cron scheduled
+            where locked_by is null -- not in progress
+            and handler NOT LIKE '%job_class: Storages::ManageNextcloudIntegrationEventsJob%' -- no need to migrate. It will be run later with cron.
+            and cron is null -- not cron schedule
+            FOR UPDATE; -- to prevent potentialy running delayed_job process working on these jobs(delayed_job uses SELECT FOR UPDATE to get workable jobs)
         SQL
         tuples.each do |tuple|
-          job_data = YAML.load(tuple['handler'],
-                               permitted_classes: [ActiveJob::QueueAdapters::DelayedJobAdapter::JobWrapper])
-                      .job_data
+          handler = tuple['handler'].gsub('ruby/object:ActiveJob::QueueAdapters::DelayedJobAdapter::JobWrapper',
+                                          "ruby/object:#{RemoveDelayedJobs::JobWrapperDeserializationMock.name}")
+          job_data = YAML.load(handler, permitted_classes: [RemoveDelayedJobs::JobWrapperDeserializationMock])
+                         .job_data
           new_uuid = SecureRandom.uuid
           good_job_record = GoodJob::BaseExecution.new
           good_job_record.id = new_uuid
@@ -58,14 +71,14 @@ def change
     end
 
     drop_table :delayed_jobs do |t|
-      t.integer :priority, default: 0   # Allows some jobs to jump to the front of the queue
-      t.integer :attempts, default: 0   # Provides for retries, but still fail eventually.
-      t.text :handler                   # YAML-encoded string of the object that will do work
-      t.text :last_error                # reason for last failure (See Note below)
-      t.datetime :run_at                # When to run. Could be Time.zone.now for immediately, or sometime in the future.
-      t.datetime :locked_at             # Set when a client is working on this object
-      t.datetime :failed_at             # Set when all retries have failed (actually, by default, the record is deleted instead)
-      t.string :locked_by               # Who is working on this object (if locked)
+      t.integer :priority, default: 0
+      t.integer :attempts, default: 0
+      t.text :handler
+      t.text :last_error
+      t.datetime :run_at
+      t.datetime :locked_at
+      t.datetime :failed_at
+      t.string :locked_by
       t.timestamps null: true
       t.string :queue
       t.string :cron