diff options
Diffstat (limited to 'app/models/concerns/cascading_namespace_setting_attribute.rb')
| -rw-r--r-- | app/models/concerns/cascading_namespace_setting_attribute.rb | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/app/models/concerns/cascading_namespace_setting_attribute.rb b/app/models/concerns/cascading_namespace_setting_attribute.rb new file mode 100644 index 00000000000..2b4a108a9a0 --- /dev/null +++ b/app/models/concerns/cascading_namespace_setting_attribute.rb @@ -0,0 +1,241 @@ +# frozen_string_literal: true + +# +# Cascading attributes enables managing settings in a flexible way. +# +# - Instance administrator can define an instance-wide default setting, or +# lock the setting to prevent change by group owners. +# - Group maintainers/owners can define a default setting for their group, or +# lock the setting to prevent change by sub-group maintainers/owners. +# +# Behavior: +# +# - When a group does not have a value (value is `nil`), cascade up the +# hierarchy to find the first non-nil value. +# - Settings can be locked at any level to prevent groups/sub-groups from +# overriding. +# - If the setting isn't locked, the default can be overridden. +# - An instance administrator or group maintainer/owner can push settings values +# to groups/sub-groups to override existing values, even when the setting +# is not otherwise locked. +# +module CascadingNamespaceSettingAttribute + extend ActiveSupport::Concern + include Gitlab::Utils::StrongMemoize + + class_methods do + def cascading_settings_feature_enabled? + ::Feature.enabled?(:cascading_namespace_settings, default_enabled: true) + end + + private + + # Facilitates the cascading lookup of values and, + # similar to Rails' `attr_accessor`, defines convenience methods such as + # a reader, writer, and validators. + # + # Example: `cascading_attr :delayed_project_removal` + # + # Public methods defined: + # - `delayed_project_removal` + # - `delayed_project_removal=` + # - `delayed_project_removal_locked?` + # - `delayed_project_removal_locked_by_ancestor?` + # - `delayed_project_removal_locked_by_application_setting?` + # - `delayed_project_removal?` (only defined for boolean attributes) + # - `delayed_project_removal_locked_ancestor` - Returns locked namespace settings object (only namespace_id) + # + # Defined validators ensure attribute value cannot be updated if locked by + # an ancestor or application settings. + # + # Requires database columns be present in both `namespace_settings` and + # `application_settings`. + def cascading_attr(*attributes) + attributes.map(&:to_sym).each do |attribute| + # public methods + define_attr_reader(attribute) + define_attr_writer(attribute) + define_lock_methods(attribute) + alias_boolean(attribute) + + # private methods + define_validator_methods(attribute) + define_after_update(attribute) + + validate :"#{attribute}_changeable?" + validate :"lock_#{attribute}_changeable?" + + after_update :"clear_descendant_#{attribute}_locks", if: -> { saved_change_to_attribute?("lock_#{attribute}", to: true) } + end + end + + # The cascading attribute reader method handles lookups + # with the following criteria: + # + # 1. Returns the dirty value, if the attribute has changed. + # 2. Return locked ancestor value. + # 3. Return locked instance-level application settings value. + # 4. Return this namespace's attribute, if not nil. + # 5. Return value from nearest ancestor where value is not nil. + # 6. Return instance-level application setting. + def define_attr_reader(attribute) + define_method(attribute) do + strong_memoize(attribute) do + next self[attribute] unless self.class.cascading_settings_feature_enabled? + + next self[attribute] if will_save_change_to_attribute?(attribute) + next locked_value(attribute) if cascading_attribute_locked?(attribute) + next self[attribute] unless self[attribute].nil? + + cascaded_value = cascaded_ancestor_value(attribute) + next cascaded_value unless cascaded_value.nil? + + application_setting_value(attribute) + end + end + end + + def define_attr_writer(attribute) + define_method("#{attribute}=") do |value| + clear_memoization(attribute) + + super(value) + end + end + + def define_lock_methods(attribute) + define_method("#{attribute}_locked?") do + cascading_attribute_locked?(attribute) + end + + define_method("#{attribute}_locked_by_ancestor?") do + locked_by_ancestor?(attribute) + end + + define_method("#{attribute}_locked_by_application_setting?") do + locked_by_application_setting?(attribute) + end + + define_method("#{attribute}_locked_ancestor") do + locked_ancestor(attribute) + end + end + + def alias_boolean(attribute) + return unless Gitlab::Database.exists? && type_for_attribute(attribute).type == :boolean + + alias_method :"#{attribute}?", attribute + end + + # Defines two validations - one for the cascadable attribute itself and one + # for the lock attribute. Only allows the respective value to change if + # an ancestor has not already locked the value. + def define_validator_methods(attribute) + define_method("#{attribute}_changeable?") do + return unless cascading_attribute_changed?(attribute) + return unless cascading_attribute_locked?(attribute) + + errors.add(attribute, s_('CascadingSettings|cannot be changed because it is locked by an ancestor')) + end + + define_method("lock_#{attribute}_changeable?") do + return unless cascading_attribute_changed?("lock_#{attribute}") + + if cascading_attribute_locked?(attribute) + return errors.add(:"lock_#{attribute}", s_('CascadingSettings|cannot be changed because it is locked by an ancestor')) + end + + # Don't allow locking a `nil` attribute. + # Even if the value being locked is currently cascaded from an ancestor, + # it should be copied to this record to avoid the ancestor changing the + # value unexpectedly later. + return unless self[attribute].nil? && public_send("lock_#{attribute}?") # rubocop:disable GitlabSecurity/PublicSend + + errors.add(attribute, s_('CascadingSettings|cannot be nil when locking the attribute')) + end + + private :"#{attribute}_changeable?", :"lock_#{attribute}_changeable?" + end + + # When a particular group locks the attribute, clear all sub-group locks + # since the higher lock takes priority. + def define_after_update(attribute) + define_method("clear_descendant_#{attribute}_locks") do + self.class.where(namespace_id: descendants).update_all("lock_#{attribute}" => false) + end + + private :"clear_descendant_#{attribute}_locks" + end + end + + private + + def locked_value(attribute) + ancestor = locked_ancestor(attribute) + return ancestor.read_attribute(attribute) if ancestor + + Gitlab::CurrentSettings.public_send(attribute) # rubocop:disable GitlabSecurity/PublicSend + end + + def locked_ancestor(attribute) + return unless self.class.cascading_settings_feature_enabled? + return unless namespace.has_parent? + + strong_memoize(:"#{attribute}_locked_ancestor") do + self.class + .select(:namespace_id, "lock_#{attribute}", attribute) + .where(namespace_id: namespace_ancestor_ids) + .where(self.class.arel_table["lock_#{attribute}"].eq(true)) + .limit(1).load.first + end + end + + def locked_by_ancestor?(attribute) + return false unless self.class.cascading_settings_feature_enabled? + + locked_ancestor(attribute).present? + end + + def locked_by_application_setting?(attribute) + return false unless self.class.cascading_settings_feature_enabled? + + Gitlab::CurrentSettings.public_send("lock_#{attribute}") # rubocop:disable GitlabSecurity/PublicSend + end + + def cascading_attribute_locked?(attribute) + locked_by_ancestor?(attribute) || locked_by_application_setting?(attribute) + end + + def cascading_attribute_changed?(attribute) + public_send("#{attribute}_changed?") # rubocop:disable GitlabSecurity/PublicSend + end + + def cascaded_ancestor_value(attribute) + return unless namespace.has_parent? + + # rubocop:disable GitlabSecurity/SqlInjection + self.class + .select(attribute) + .joins("join unnest(ARRAY[#{namespace_ancestor_ids.join(',')}]) with ordinality t(namespace_id, ord) USING (namespace_id)") + .where("#{attribute} IS NOT NULL") + .order('t.ord') + .limit(1).first&.read_attribute(attribute) + # rubocop:enable GitlabSecurity/SqlInjection + end + + def application_setting_value(attribute) + Gitlab::CurrentSettings.public_send(attribute) # rubocop:disable GitlabSecurity/PublicSend + end + + def namespace_ancestor_ids + strong_memoize(:namespace_ancestor_ids) do + namespace.self_and_ancestors(hierarchy_order: :asc).pluck(:id).reject { |id| id == namespace_id } + end + end + + def descendants + strong_memoize(:descendants) do + namespace.descendants.pluck(:id) + end + end +end |