OPA Server

The OPA (Open Policy Agent) server is a critical component of the OPA ecosystem, serving as a central policy decision point. It's a standalone service that evaluates policies written in the Rego language and makes access control decisions based on those policies. The OPA server allows for efficient policy enforcement across various parts of a software stack, including microservices, APIs, and cloud infrastructure. It receives policy queries, typically in the form of JSON or structured data, and returns decisions, enabling fine-grained control over authorization and compliance. With its ability to scale and distribute policy evaluations, the OPA server plays a crucial role in ensuring consistent and dynamic policy enforcement in complex, modern, and cloud-native environments, enhancing security and governance across the entire system.

The OpenPolicyAgent.Server module includes methods to help start the OPA server, monitor it for failures, and restart when required.

function start_opa_server(root_path)
    opa_server = OpenPolicyAgent.Server.MonitoredOPAServer(
        joinpath(root_path, "config.yaml"),
        stdout = joinpath(root_path, "server.stdout"),
        stderr = joinpath(root_path, "server.stderr"),
    )
    OpenPolicyAgent.Server.start!(opa_server)
    return opa_server
end

start_opa_server("/tmp/opaserver")

Complete reference is available in the Reference section.