Substitution Mappings

TOSCA lets you replace a node template in one topology with another topology in its entirety. To make a topology available for substitution, add a substitution_mappings section to the topology template. To use this topology in another topology, declare a node template with a substitute directive and Unfurl will find a matching topology to replace the node template.

The substitution_mappings section describes how to map the topology to the substituted node template’s type, properties, attributes, and requirements. As a TOSCA extension, Unfurl adds a node key to point to a node template in that topology to be used to replace the substituted node template in the other topology. This way, you don’t need to provide a full mapping.

In addition, root can be used as an alias for the substitution_mappings keyword. This is also used by Unfurl to figure out which node templates to include in the plan for a deployment job. If it is present, only node templates reachable from that root template will be included in the plan. If it is not declared, all node templates in the topology will be included.

Declaration

substitution_mappings:  # or root:

   node: <node_template_name>  # unfurl extension

   node_type: <node_type_name>

   substitution_filter: <node_filter>

   properties:  # mapping to map topology inputs to node template properties

     <property_mappings>

   attributes: # mappings to map topology outputs to node template attributes

     <attribute_mappings>

   requirements:

     <requirement_mappings>

   capabilities:   # currently unsupported

     <capability_mappings>

   interfaces:    # currently unsupported

     <interface_mappings>