Remove rake task to migrate all legacy attachments

db/post_migrate/20200409211607_migrate_legacy_attachments.rb

@@ -7,9 +7,9 @@ class MigrateLegacyAttachments < ActiveRecord::Migration[6.0]
 
   DOWNTIME = false
 
-  MIGRATION = 'LegacyUploadsMigrator'.freeze
+  MIGRATION = 'LegacyUploadsMigrator'
   BATCH_SIZE = 5000
-  DELAY_INTERVAL = 5.minutes.to_i
+  INTERVAL = 5.minutes.to_i
 
   class Upload < ActiveRecord::Base
     self.table_name = 'uploads'
@@ -18,12 +18,10 @@ class MigrateLegacyAttachments < ActiveRecord::Migration[6.0]
   end
 
   def up
-    Upload.where(uploader: 'AttachmentUploader', model_type: 'Note').each_batch(of: BATCH_SIZE) do |relation, index|
-      start_id, end_id = relation.pluck('MIN(id), MAX(id)').first
-      delay = index * delay_interval
-
-      BackgroundMigrationWorker.perform_in(delay, migration, [start_id, end_id])
-    end
+    queue_background_migration_jobs_by_range_at_intervals(Upload.where(uploader: 'AttachmentUploader', model_type: 'Note'),
+                                                          MIGRATION,
+                                                          INTERVAL,
+                                                          batch_size: BATCH_SIZE)
   end
 
   def down

doc/administration/raketasks/uploads/migrate.md

@@ -111,24 +111,6 @@ sudo -u git -H bundle exec rake "gitlab:uploads:migrate[FileUploader, MergeReque
 sudo -u git -H bundle exec rake "gitlab:uploads:migrate[DesignManagement::DesignV432x230Uploader, DesignManagement::Action]"
 ```
 
-## Migrate legacy uploads out of deprecated paths
-
-> Introduced in GitLab 12.3.
-
-To migrate all uploads created by legacy uploaders, run:
-
-**Omnibus Installation**
-
-```shell
-gitlab-rake gitlab:uploads:legacy:migrate
-```
-
-**Source Installation**
-
-```shell
-bundle exec rake gitlab:uploads:legacy:migrate
-```
-
 ## Migrate from object storage to local storage
 
 If you need to disable Object Storage for any reason, first you need to migrate

lib/tasks/gitlab/uploads/legacy.rake

-# frozen_string_literal: true
-
-namespace :gitlab do
-  namespace :uploads do
-    namespace :legacy do
-      desc "GitLab | Uploads | Migrate all legacy attachments"
-      task migrate: :environment do
-        class Upload < ApplicationRecord
-          self.table_name = 'uploads'
-
-          include ::EachBatch
-        end
-
-        migration = 'LegacyUploadsMigrator'
-        batch_size = 5000
-        delay_interval = 5.minutes.to_i
-
-        Upload.where(uploader: 'AttachmentUploader', model_type: 'Note').each_batch(of: batch_size) do |relation, index|
-          start_id, end_id = relation.pluck('MIN(id), MAX(id)').first
-          delay = index * delay_interval
-
-          BackgroundMigrationWorker.perform_in(delay, migration, [start_id, end_id])
-        end
-      end
-    end
-  end
-end