1 files changed, 59 insertions, 0 deletions
diff --git a/db/post_migrate/20221215151822_schedule_backfill_releases_author_id.rb b/db/post_migrate/20221215151822_schedule_backfill_releases_author_id.rb
new file mode 100644
index 00000000000..4d8343ca2dd
--- /dev/null
+++ b/db/post_migrate/20221215151822_schedule_backfill_releases_author_id.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+class ScheduleBackfillReleasesAuthorId < Gitlab::Database::Migration[2.1]
+  MIGRATION = 'BackfillReleasesAuthorId'
+  JOB_DELAY_INTERVAL = 2.minutes
+  GHOST_USER_TYPE = 5
+
+  restrict_gitlab_migration gitlab_schema: :gitlab_main
+
+  class User < MigrationRecord
+    self.table_name = 'users'
+  end
+
+  class Release < MigrationRecord
+    self.table_name = 'releases'
+  end
+
+  def up
+    unless release_with_empty_author_exists?
+      say "There are no releases with empty author_id, so skipping migration #{self.class.name}"
+      return
+    end
+
+    create_ghost_user if ghost_user_id.nil?
+
+    queue_batched_background_migration(
+      MIGRATION,
+      :releases,
+      :id,
+      ghost_user_id,
+      job_interval: JOB_DELAY_INTERVAL
+    )
+  end
+
+  def down
+    delete_batched_background_migration(MIGRATION, :releases, :id, [ghost_user_id])
+  end
+
+  private
+
+  def ghost_user_id
+    User.find_by(user_type: GHOST_USER_TYPE)&.id
+  end
+
+  def create_ghost_user
+    user = User.new
+    user.name = 'Ghost User'
+    user.username = 'ghost'
+    user.email = 'ghost@example.com'
+    user.user_type = GHOST_USER_TYPE
+    user.projects_limit = 100000
+
+    user.save!
+  end
+
+  def release_with_empty_author_exists?
+    Release.exists?(author_id: nil)
+  end
+end