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Script policy_create.py  creates data_type that can be used by policy_type.
In context of Closed Loop, policy type describes how to create microservice policy (maybe operation policy in future) in Clamp.
Policy types and Data types are extracted by Clamp from CSAR file created by SDC.

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Control Loop Artifacts

CSAR package contains 3 artifacts required by Clamp to create closed loop:

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As you can see on scheme to deploy* closed loop Clamp uses DCEA_INVENTORY_BLUEPRINT.
Each node that is deployed has to have specified it's policy type.
From Analytic Microservice perspective it's policy type is a scheme of how microservice it's configuration should look like.
If node doesn't have specified policy type Clamp assumes it's default one onap.policy.monitoring.cdap.tca.hi.lo.app
Policy types described inside policies.yml can have sub-nodes. Those sub-nodes are data types. Their are They're described inside artifact data.yml.

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It's simplification. Clamp requests DCAE to deploy microservice.

Tosca Lab policy create

Dublin constraint is that both data.yml and policies.yml are hardcoded and can't be extended in runtime.

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