Official

The Open Policy Agent (OPA, pronounced “oh-pa”) is an open source, general-purpose policy engine that unifies policy enforcement across the stack.
https://www.openpolicyagent.org/

SQLの利用例(公式Linkより)

Write Policy in OPA. Enforce Policy in SQL.
https://blog.openpolicyagent.org/write-policy-in-opa-enforce-policy-in-sql-d9d24db93bf4

Terraformでの利用例

https://www.openpolicyagent.org/docs/latest/terraform/

Open-Policy Administration Layer

https://www.opal.ac/

Architecture

https://github.com/authorizon/opal/blob/master/docs/architecture.md

Getting started with Docker

https://github.com/authorizon/opal/blob/master/docs/HOWTO/get_started_with_opal_using_docker.md