Add task to backfill log downloads

app/tasks/maintenance/backfill_log_downloads_from_log_tickets_task.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Maintenance
+  # This task is used to backfill log downloads from log tickets.
+  # It is used to migrate from past to present using created_at date to order
+  # limit 500 per iteration and use latest created_at date to get the next 500
+  # later union with pending tickets.
+  class BackfillLogDownloadsFromLogTicketsTask < MaintenanceTasks::Task
+    def collection
+      # migrate from past to present using created_at date to order
+      # limit 500 per iteration and use latest created_at date to get the next 500
+      # later union with pending tickets
+      scope = LogTicket.processed.order(created_at: :asc)
+      last_created_at = LogDownload.latest_created_at
+      scope = scope.where("created_at < ?", last_created_at) if last_created_at
+      scope
+        .limit(500)
+        .union(LogTicket.pending.order(created_at: :asc).limit(500))
+    end
+
+    def process(batch)
+      LogDownload.insert_all(batch.select(:id, :status, :directory, :key, :created_at).to_a.map(&:attributes))
+    end
+  end
+end

test/tasks/maintenance/backfill_log_downloads_from_log_tickets_task_test.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+module Maintenance
+  class BackfillLogDownloadsFromLogTicketsTaskTest < ActiveSupport::TestCase
+    setup do
+      # create a list of log ticket  statuses
+      @log_ticket_statuses = %w[pending processed]
+      @log_ticket_statuses.each do |status|
+        3.times { create(:log_ticket, status: status) }
+      end
+    end
+
+    test "#process performs a task iteration" do
+      assert_equal LogTicket.count, 6
+      assert_equal LogDownload.count, 0
+      Maintenance::BackfillLogDownloadsFromLogTicketsTask.process(LogTicket.all)
+      assert_equal LogDownload.count, 6
+    end
+  end
+end