opa-jackson

opa-jackson

Jackson-based OPA IR deserialization for the java-opa-sdk.

Overview

This module provides the JacksonPolicyReader, a PolicyReader SPI implementation that deserializes OPA Intermediate Representation (IR) plans using Jackson. It is automatically discovered at runtime via java.util.ServiceLoader when loading bundles with TarballBundleLoader.

How It Works

When the evaluator loads a bundle (e.g., bundle.tar.gz), it uses ServiceLoader to find a PolicyReader implementation. This module provides that implementation, which:

1. Reads the plan.json from the bundle
2. Deserializes the IR using custom Jackson deserializers registered via IrModule
3. Returns the parsed policy plan to the evaluator engine

Dependencies

• jackson-databind - Core JSON processing
• jackson-dataformat-yaml - YAML support for configuration files
• jackson-datatype-jsr310 - Java 8 date/time type support

Typical Usage

No direct usage is required. Simply include this module on the classpath and it will be discovered automatically:

// TarballBundleLoader uses ServiceLoader to find JacksonPolicyReader
Engine engine = new Engine.Builder()
    .withBundleLoader(new TarballBundleLoader("authz", Path.of("examples/policy.tar.gz")))
    .withEntrypoint("example/allow")
    .build();

Key Classes

Class	Description
JacksonPolicyReader	PolicyReader SPI implementation using Jackson
IrModule	Jackson module registering custom IR type deserializers