Merge branch '216970-add-instance-to-service-if-missing' into 'master'

Add instance column to services table if it's missing

Closes #216970

See merge request gitlab-org/gitlab!31631

changelogs/unreleased/216970-add-instance-to-service-if-missing.yml

+---
+title: Add instance column to services table if it's missing
+merge_request: 31631
+author:
+type: fixed

db/post_migrate/20200511162057_add_missing_instance_to_servicess.rb

+# frozen_string_literal: true
+
+class AddMissingInstanceToServicess < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  # This is a corrective migration to keep the instance column.
+  # Upgrade from 12.7 to 12.9 removes the instance column as it was first added
+  # in the normal migration and then removed in the post migration.
+  #
+  # 12.8 removed the instance column in a post deployment migration https://gitlab.com/gitlab-org/gitlab/-/merge_requests/24885
+  # 12.9 added the instance column in a normal migration https://gitlab.com/gitlab-org/gitlab/-/merge_requests/25714
+  #
+  # rubocop:disable Migration/AddColumnWithDefault
+  # rubocop:disable Migration/UpdateLargeTable
+  def up
+    unless column_exists?(:services, :instance)
+      add_column_with_default(:services, :instance, :boolean, default: false)
+    end
+  end
+  # rubocop:enable Migration/AddColumnWithDefault
+  # rubocop:enable Migration/UpdateLargeTable
+
+  def down
+    # Does not apply
+  end
+end

db/post_migrate/20200511162115_add_missing_index_to_service_unique_instance_per_type.rb

+# frozen_string_literal: true
+
+class AddMissingIndexToServiceUniqueInstancePerType < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  # This is a corrective migration to keep the index on instance column.
+  # Upgrade from 12.7 to 12.9 removes the instance column as it was first added
+  # in the normal migration and then removed in the post migration.
+  #
+  # 12.8 removed the instance column in a post deployment migration https://gitlab.com/gitlab-org/gitlab/-/merge_requests/24885
+  # 12.9 added the instance column in a normal migration https://gitlab.com/gitlab-org/gitlab/-/merge_requests/25714
+  def up
+    unless index_exists_by_name?(:services, 'index_services_on_type_and_instance')
+      add_concurrent_index(:services, [:type, :instance], unique: true, where: 'instance IS TRUE')
+    end
+  end
+
+  def down
+    # Does not apply
+  end
+end

db/structure.sql

@@ -13792,6 +13792,8 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200511121610
 20200511121620
 20200511145545
+20200511162057
+20200511162115
 20200512085150
 \.