Get a field instance's settings What's the equivalent of field_info_instance() for Drupal 8?

The default field settings are stored as configuration in a file like field.field.ENTITYTYPE.BUNDLE.FIELDNAME.yml, but how do I get their current value?
Using the entity_field.manager service, you are able to get an array of BaseFieldDefinition classes. This service is injectable as well, but for copy-paste working code, you can do the following:

$bundle_fields = \Drupal::getContainer()-&gt;get('entity_field.manager')-&gt;getFieldDefinitions($entity_type, $bundle);
$field_definition = $bundle_fields[$field_name];
$catalog_id = $field_definition-&gt;getSetting($setting_name);