Overview

This example includes the models of two services. These services are very loosely coupled. None of them contains any direct reference to another. In fact, they are totally unaware of the existence of each another. The relationship between them is established by the orchestrator in runtime based on a few global type definitions.

Shared type definitions

These definitions are included into both the providing and the consuming services.

Core DM Types

Node type onap.nodes.Service

Node type onap.nodes.Resource

Node type onap.nodes.NetworkFunction

Capability type onap.capabilities,AllottedResorceProvider

Relationship type onap.relationships.AllottedBy

Imaginary Types made up for this example

capability_types:
  onap.examples.capabilities.Firewall:
    derived_from: tosca.capabilities.Root
    description: an ability to serve as a firewall

node_types:
  onap.examples.nodes.Firewall:
    derived_from: tosca.nodes.Root
    description: an abstract firewall
    capabilities:
      i_can_be_a_firewall:
        type: onap.examples.capabilities.Firewall 

Providing Service

The Providing Service CSAR will include these definitions and templates along with the Shared Type Definitions.

An implementation of the onap.capabilities.AllottedResource by the providing vendor.

The providing service will most likely define its own subtype the ONAP DM's onap.capabilities.AllottedResourceProvider capability type - to augment this core type with its own properties and a restricted list of valid source types.

capability_types:
  vendorXXX.capabilities.FirewallsProvider:
    derived_from: onap.capabilities.AllottedResourceProvider
    valid_source_types: [onap.examples.nodes.Firewall]

The "Interface node type" for this service 

According to the Service Model Principles, any service definition will include a node type derived from onap.nodes.Service. This is a general ONAP service modeling convention rather than something specific for AR providing services. Just to remind - this type may be later use to create nodes of embedded services in a higher-order topology.

node_types:
  vendorXXX.nodes.FirewallsProvidingService:
    derived_from: onap.nodes.Service
    capabilities:
      i_can_provide_firewalls:
        type: vendorXXX.capabilities.FirewallsProvider

Firewall implementation node type

This is a concrete node type, implementing the shared generic type definition of onap.examples.nodes.Firewall.

node_types:
  vendorXXX.nodes.MyVerySpecialFirewall:
    derived_from: onap.examples.nodes.Firewall
    capabilities:
      i_can_be_a_firewall:
        type: vendorXXX.capabilities.Firewall
      i_can_provide_firewalls:
        type: vendorXXX.capabilities.FirewallsProvider
    properties:
      # extra props
    interfaces:
      Standard:
        create: my_creation_script.sh # AR creation logic
        delete: my_delete_script.sh

The example above shows one of the possible ways to implement a node type, through implementation script artifacts. These scripts may include a special logic that communicates to a "factory" node inside the service. In this example, the capability of being a firewall and the capability of providing firewall are combined in one node. More elaborate designs may separate these functionalities and have a dedicated node for each of them.

All other TOSCA ways to implement an abstract node are also valid. Foe example, a vendor may choose to have an implementing (substituting) topology for this node type.

Providing service topology

Service Model Principles stipulate that any ONAP service definition includes, besides the "interface" node type, the implementing topology. The AR services are no exception of this principle.

topology_template:       
  node_templates:
    my_firewall:
      type: vendorXXX.nodes.MyVerySpecialFirewall
           
  substitution_mappings:
    type: vendorXXX.nodes.FirewallsProvidingService
    capabilities:
      i_can_provide_firewalls: [my_firewall, i_can_provide_firewalls]
       

TODO: separate nodes for the share and the "manager"

Consuming Service

The "Interface node type" of the Consuming Service 

The Consuming service definition, like any other ONAP service definition, will include an "interface node type". Its details are irrelevant for this example.

Consuming Service Topology

The service topology includes firewall abstract nodes.

node_types:
  onap.examples.nodes.FirewallShare:
    derived_from: onap.examples.nodes.Firewall
    description: an abstract firewall as AR
    requirements:
      - i_need_a_providing_service:
          capability: onap.capabilities.AllottedResourceProvider 


topology_template:
  node_templates:
 
    # A more released abstraction of a firewall, can be implemented by any way including an allotted resource
    firewall_1:
      type: onap.examples.nodes.Firewall
 
    # A more restricted abstraction - must be resolved by an allotted resource
    firewall_2:
      type: onap.examples.nodes.FirewallShare
 

TODO: add a section on the orchestration logic