Use of properties defaults

Hello Chris and Calin,

The use of default values for properties in TOSCA is a recurrent topic of controversy in ETSI NFV SOL.

What has been stated in the TOSCA Language WG is that default values are only meaningful for properties that are defined as required = true e.g. in a node type definition.

A default value for a property that is defined as required = false in a node type definition is irrelevant and it will never be used: a node template either provides a property assignment for that property (in which case the default value is overrriden) or it does not provide a property assignment (in which case the property is not used in this node template).

Unfortunately this is not explicitly written in the TOSCA spec. Furthermore, there is at least one example in 3.4.5.7 in TOSCA 2.0 with a default value for a property which has required = false. In TOSCA 1.3 there are a few more examples but these are in the profile part.

Can we discuss this topic briefly tomorrow and add a clarification in TOSCA about the use of defaults?

Best regards,

Arturo

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