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Please see the TOSCA Policy Primer page for an introduction to TOSCA policy concepts.
TOSCA defines a PolicyType, the definition of a type of policy that can be applied to a service. It also defines a Policy, the definition of an instance of a policy. In the Policy Framework, we must handle and manage these TOSCA definitions and tie them to real implementations of policies that can run on PDPs.
The diagram above outlines how we achieve this. Each TOSCA PolicyType must have a corresponding PolicyTypeImpl in the Policy Framework. The TOSCA PolicyType definition is used to create a TOSCA Policy definition, either directly by the Policy Framework, by CLAMP, or by some other system. Once the Policy artifact exists, it can be used together with the PolicyTypeImpl artifact to create a PolicyImpl artifact. A PolicyImpl artifact is an executable policy implementation that can run on a PDP.
1 Policy Type Design
In Policy Type Design, a TOSCAPolicyType artifact and its implementation (a PolicyTypeImpl) are defined.
During Model Design, a Policy Model and a Policy Model Parameter Schema is created. The Policy Model contains the definition of the policy together with its inputs and outputs, rules and logic. This model may be expressed in XACML, as Drools rules, or as an APEX model definition. The Policy Model Parameter Schema is a TOSCA definition of the parameters that a Policy Model must receive in order for it to be transformed into a policy. The schemas will ultimately be defined by the modeling team but for now are defined by the Policy Framework project.
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