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 type onap.examples.capabilities.Firewall 
capability_types:
  onap.examples.capabilities.Firewall:
    derived_from: tosca.capabilities.Root
    description: an ability to serve as a firewall
Node type onap.examples.node.Firewall 
node_types:
  onap.examples.nodes.Firewall:
    derived_from: onap.nodes.NetworkFunction
    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.

The specialized capability type 
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.

Providing Service, "interface" node type 
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.

Firewall implementing node type 
node_types:
  vendorXXX.nodes.MyVerySpecialFirewall:
    derived_from: onap.examples.nodes.Firewall
    capabilities:
      i_can_be_a_firewall:
        type: vendorXXX.capabilities.Firewall
    requirements:      
      - provider_service          
        node: vendorXXX.nodes.FirewallsProvidingService          
        capability: vendorXXX.capabilities.FirewallsProvider          
        relationship:  onap.relationships.AllottedBy
    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. 

All other TOSCA ways to implement an abstract node are also valid. For 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.

AR Providing Service Topology 
topology_template:       
  node_templates:
    # the provider service topology captures the guts of what's required to be instantiated in order
    # to be prepared to allot, e.g., the allotted firewall network functions
    some_vnf:
      type: some.concrete.type.which.forms.the.internals.of.the.provider.service


    possibly_some_other_vnf:
      type: also.some.concrete.type.which.forms.the.internals.of.the.provider.service
           
  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.

Consuming service topology 
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 unconstrained 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
    
    # service designer specifies the exact allotted firewall
    firewall_3:
      type: vendorXXX.nodes.MyVerySpecialFirewall


TODO: add a section on the orchestration logic




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