Cleanup background migrations for any approval rules

It executes all the remaining background jobs which
migrate approval rules for projects and merge requests

It also makes sure that the data migrated correctly and
executes the code synchronously one more time

changelogs/unreleased/id-cleanup-anny-approver-migrations.yml

+---
+title: Cleanup background migrations for any approval rules
+merge_request: 18256
+author:
+type: changed

db/post_migrate/20191007163701_populate_remaining_any_approver_rules_for_merge_requests.rb

+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class PopulateRemainingAnyApproverRulesForMergeRequests < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BATCH_SIZE = 10_000
+  MIGRATION = 'PopulateAnyApprovalRuleForMergeRequests'
+
+  disable_ddl_transaction!
+
+  class MergeRequest < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'merge_requests'
+
+    scope :with_approvals_before_merge, -> { where.not(approvals_before_merge: 0) }
+  end
+
+  def up
+    return unless Gitlab.ee?
+
+    add_concurrent_index :merge_requests, :id,
+      name: 'tmp_merge_requests_with_approvals_before_merge',
+      where: 'approvals_before_merge != 0'
+
+    Gitlab::BackgroundMigration.steal(MIGRATION)
+
+    PopulateRemainingAnyApproverRulesForMergeRequests::MergeRequest.with_approvals_before_merge.each_batch(of: BATCH_SIZE) do |batch|
+      range = batch.pluck('MIN(id)', 'MAX(id)').first
+
+      Gitlab::BackgroundMigration::PopulateAnyApprovalRuleForMergeRequests.new.perform(*range)
+    end
+
+    remove_concurrent_index_by_name(:merge_requests, 'tmp_merge_requests_with_approvals_before_merge')
+  end
+
+  def down
+    # no-op
+  end
+end

db/post_migrate/20191007163736_populate_remaining_any_approver_rules_for_projects.rb

+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class PopulateRemainingAnyApproverRulesForProjects < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BATCH_SIZE = 5_000
+  MIGRATION = 'PopulateAnyApprovalRuleForProjects'
+
+  disable_ddl_transaction!
+
+  class Project < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'projects'
+
+    scope :with_approvals_before_merge, -> { where.not(approvals_before_merge: 0) }
+  end
+
+  def up
+    return unless Gitlab.ee?
+
+    add_concurrent_index :projects, :id,
+      name: 'tmp_projects_with_approvals_before_merge',
+      where: 'approvals_before_merge != 0'
+
+    Gitlab::BackgroundMigration.steal(MIGRATION)
+
+    PopulateRemainingAnyApproverRulesForProjects::Project.with_approvals_before_merge.each_batch(of: BATCH_SIZE) do |batch|
+      range = batch.pluck('MIN(id)', 'MAX(id)').first
+
+      Gitlab::BackgroundMigration::PopulateAnyApprovalRuleForProjects.new.perform(*range)
+    end
+
+    remove_concurrent_index_by_name(:projects, 'tmp_projects_with_approvals_before_merge')
+  end
+
+  def down
+    # no-op
+  end
+end