The Open Policy Agent (OPA, pronounced “oh-pa”) is an open source, general-purpose policy engine that unifies policy enforcement across the stack. OPA provides a high-level declarative language that lets you specify policy as code and simple APIs to offload policy decision-making from your software. You can use OPA to enforce policies in microservices, Kubernetes, CI/CD pipelines, API gateways, and more.

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OPA decouples policy decision-making from policy enforcement. When your software needs to make policy decisions it queries OPA and supplies structured data (e.g., JSON) as input. OPA accepts arbitrary structured data as input.

OPA generates policy decisions by evaluating the query input against policies and data. OPA and Rego are domain-agnostic so you can describe almost any kind of invariant in your policies. For example:

• Which users can access which resources.
• Which subnets egress traffic is allowed to.
• Which clusters a workload must be deployed to.
• Which registries binaries can be downloaded from.
• Which OS capabilities a container can execute with.
• Which times of day the system can be accessed at.

Policy decisions are not limited to simple yes/no or allow/deny answers. Like query inputs, your policies can generate arbitrary structured data as output.

Rego

OPA policies are expressed in a high-level declarative language called Rego. Rego (pronounced “ray-go”) is purpose-built for expressing policies over complex hierarchical data structures. For detailed information on Rego see the Policy Language documentation.

For more information, please visit : https://www.openpolicyagent.org/docs/latest/#running-opa

Read this page to learn about the core concepts in OPA’s policy language (Rego) as well as how to download, run, and integrate OPA.

OPA was originally created by Styra and is proud to be a graduated project in the Cloud Native Computing Foundation (CNCF) landscape. For details read the CNCF announcement