tosca_definitions_version: tosca_simple_yaml_1_3 metadata: template_name: Attributes Example template_author: Puccini node_types: Backup: # Unlike "properties", you can't mark an attribute as required or not # Attributes are *always* added to the node template, even if they have not been assigned # If they don't have a "default" value, they will get an automatic, sensible default # (E.g., a string will get an empty string) # But this might not always match constraints, which would result in an error # So in some cases you might have to explicitly assign a default attributes: days: type: list entry_schema: DayOfWeek max_size: description: Max size type: scalar-unit.size data_types: DayOfWeek: derived_from: string constraints: - valid_values: [ su, mo, tu, we, th, fr, sa ] topology_template: node_templates: backup1: type: Backup attributes: # You can assign initial values to attributes # Though it's expected that they may change max_size: 10 gib backup2: type: Backup attributes: # There is also a long notation that lets you override the description max_size: description: Current max size value: 10 gib