get_attribute with a requirement as parameter

[philippemerle]

Parsing the following service template

tosca_definitions_version: tosca_simple_yaml_1_3
topology_template:
  node_templates:
    compute:
      type: tosca.nodes.Compute
      capabilities:
        host:
          properties:
            name: mycompute
    software:
      type: tosca.nodes.SoftwareComponent
      requirements:
        - host: compute
      interfaces:
        Standard:
          operations:
            configure:
              inputs:
                property_host_name:  { get_property: [ SELF, host, name ]}
                attribute_host_name: { get_attribute: [ SELF, host, name ]}

produces an error

[ERROR] issue.yaml@21,38:topology_template:node_templates:software:interfaces:Standard:operations:configure:inputs:attribute_host_name: {'get_attribute': ['SELF', 'host', 'name']} - host attribute undefined!

As get_property: [ SELF, host, name ] is considered as a correct expression, then get_attribute: [ SELF, host, name ] shall be considered as a correct expression.

[lauwers]

The example is invalid TOSCA in my opinion since it assigns values to properties (the "name' property of the 'host' capabilty) and input parameters('property_host_name' and 'attribute_host_name') that have not been previously defined. Ubicity generates the following error output:

     "topology": {
        "node_templates": {
          "compute": {
            "capabilities": {
              "host": {
                "properties": {
                  "name": "not previously defined"
                }
              }
            },
            "line": 4
          },
          "software": {
            "interfaces": {
              "Standard": {
                "operations": {
                  "configure": {
                    "inputs": {
                      "property_host_name": "not previously defined",
                      "attribute_host_name": "not previously defined"
                    }
                  }
                }
              }
            },
            "line": 10
          }
        },
        "line": 2
      }
    }

[philippemerle]

According to Section 5.5.3 of TOSCA 1.3, tosca.capabilities.Compute has a property named name. It seems that this property is not defined in Ubicity, see https://ubicity.com/profiles.html#/types/capability/45.

[philippemerle]

There are many examples where operation input parameters are assigned without defined previously.

[lauwers]

My apologies, you are correct about tosca.capabilities.Compute. Apparently I have had this bug since v1.1 when tosca.capabilities.Compute was first introduced as a subclass of tosca.capabiities.Container. It took over all the properties oftosca.capabilities.Container defined in v1.0, but it also added a new ``name'' property which I neglected to add.

[lauwers]

In my opinion, it is OK for a node type definition to add input parameters to an interface definition that have not been previously defined in the corresponding interface type, but I believe it should be an error for a node template to add interface inputs that have not been previously defined in the corresponding interface definition. Could you point me to one of the examples in the spec so we can discuss this in the TOSCA Language Ad-Hoc?

[philippemerle]

Have a look to examples in Sections 11.1.15.3, 11.1.16.3, 11.1.17.3.1, and 11.1.18.3.1 of TOSCA 1.3.