Hi Gabor, Thanks for the explanation, since this may not be a proper use of substitution mappings. Specifically, substitution mapping does not provide an ability for the substituting template to set property values in the substituted node. If I understand your use case, then the correct way to communicate resource requirements back to the NFVO is by using, well, requirements: Consider an abstract VNF node template that needs to be substituted Presumably, a specific flavor_id will be provided as a property value of the abstract VNF node. Based on the value of the flavor_id, the orchestrator will select the appropriate substituting template The substituting template presumably will use TOSCA requirements to express its resource requirements. These resource requirements must not be communicated back to the substituted node as property values. Instead, they need to remain as requirements that need to be fulfilled by the orchestrator. Is this inconsistent with the ETSI spec? Thanks, Chris From: Marton, Gabor (Nokia - HU/Budapest) <
gabor.marton@nokia.com> Sent: Saturday, December 15, 2018 12:46 PM To: Chris Lauwers <
lauwers@ubicity.com>;
tosca@lists.oasis-open.org Subject: RE: Question on mandatory properties vs. node type substitution Hi Chris, thanks a lot for your response. The scenario is about setting a property value in an abstract node by a substituting template, i.e. bottom-up. This unusual need, like a number of others discussed with you and other TOSCA experts in relation to ETSI NFV SOL001 (VNF descritor, NS descriptor), comes from the unusual use of TOSCA: a VNFD is at the same time (1) a descriptor with “read-only”/output values for informing the NFVO about the resource requirements of a VNF so that the NFVO can do necessary resource allocations and granting, and (2) a declarative descriptor with input values to the VNFM for defining the workload to be managed. We ended up with a VNF node type of which one property (flavour_id) is top-down (2) whereas others (flavour_description, descriptor_id, …) are bottom-up (1). Wishing you a Merry Christmas and a Happy New Year, Gábor p.s.: back in the office from 3 January. From: Chris Lauwers <
lauwers@ubicity.com > Sent: Tuesday, December 11, 2018 6:42 AM To: Marton, Gabor (Nokia - HU/Budapest) <
gabor.marton@nokia.com >;
tosca@lists.oasis-open.org Subject: RE: Question on mandatory properties vs. node type substitution Hi Gabor, Apologies for the late reply. I’m not sure if I understand your scenario correctly, but in general, property values in an abstract node will never be set by a substituting template. The must be set in the top-level template that includes the abstract node (e.g. using get_input functions) and then these values will be propagated to inputs of the substituting template (assuming the property mappings are set up correctly). Of course, since each property is automatically reflected in a corresponding attribute with the same name, the attribute values will get retrieved from the substituting template (assuming outputs of the substituting template are properly mapped onto attributes of the abstract node). Please let me know if I misunderstood your question. Thanks, Chris From:
tosca@lists.oasis-open.org <
tosca@lists.oasis-open.org > On Behalf Of Marton, Gabor (Nokia - HU/Budapest) Sent: Tuesday, November 06, 2018 12:52 AM To:
tosca@lists.oasis-open.org Subject: [tosca] Question on mandatory properties vs. node type substitution Dear TOSCA Experts, the following question is related to a problem under discussion in the ETSI NFV SOL001 group. In the below second service template (example-top.tosca.yaml), can the value of property_2 come from a substitution template? In other words, is the second service template valid? example-type.tosca.yaml: tosca_definitions_version: tosca_simple_yaml_1_2 node_types: node_type_1: derived_from: tosca.nodes.Root properties: property_1: type: string constraints: - valid_values: [ value_1, value_2 ] property_2: type: string example-top.tosca.yaml: tosca_definitions_version: tosca_simple_yaml_1_2 imports: - example-type.tosca.yaml topology_template: node_templates: node_template_1: type: node_type_1 properties: property_1: value_1 # property value constraint for matching outputs: output_1: value: { get_property: [ node_template_1, property_2 ] } # value_3 from the sole matching substitution example-subst-1.tosca.yaml: tosca_definitions_version: tosca_simple_yaml_1_2 imports: - example-type.tosca.yaml topology_template: substitution_mappings: node_type: node_type_1 properties: property_1: value_1 property_2: value_3 example-subst-2.tosca.yaml: tosca_definitions_version: tosca_simple_yaml_1_2 imports: - example-type.tosca.yaml topology_template: substitution_mappings: node_type: node_type_1 properties: property_1: value_2 property_2: value_4 In case the second service template is invalid, we need to use a work-around which is not perfect, e.g.: example-type.tosca.yaml (modified): tosca_definitions_version: tosca_simple_yaml_1_2 node_types: node_type_1: derived_from: tosca.nodes.Root properties: property_1: type: string constraints: - valid_values: [ value_1, value_2 ] property_2: type: string default: '' Looking forward to receiving your response, kind regards, Gábor