kafka_authorizer

kafka-authorizer

This directory contains a Kafka authorizer plugin that uses OPA to enforce policy decisions.

Build

To build the plugin, you must have Docker installed. If you want to build without Docker mvn install should be enough but requires that you have Java and Maven installed on your system.

Run make build to build and package the plugin.

The JARs required to run the plugin will written to ./target/kafka-authorizer-opa-<VERSION>-package/share/java/kafka-authorizer-opa.

Install

Include the following JAR files in the Kafka classpath:

• kafka-authorizer-opa-<VERSION>.jar
• gson-2.8.2.jar

Enable the plugin by adding the following to server.properties:

authorizer.class.name: com.lbg.kafka.opa.OpaAuthorizer

The plugin supports the following properties:

Property Key	Example	Description
opa.authorizer.url	http://opa:8181/v1/data/kafka/authz/allow	Name of the OPA policy to query.
opa.authorizer.allow.on.error	false	Fail-closed or fail-open if OPA call fails.
opa.authorizer.cache.initial.capacity	100	Initial decision cache size.
opa.authorizer.cache.maximum.size	100	Max decision cache size.
opa.authorizer.cache.expire.after.ms	600000	Decision cache expiry in milliseconds.
opa.authorizer.token	``	Token for authentication with OPA.

Usage

The OPA policy should return a boolean value indicating whether the action should be allowed (true) or denied (false).

The plugin provides input data describing the principal, operation, and resource.

# Example principle information.
input.session.principal.principalType = "User"
input.session.principal.name = "ANONYMOUS"
input.session.clientAddress = "127.0.0.1"
input.session.sanitizedUser = "ANONYMOUS"

# Example operation information.
input.operation.name = "ClusterAction"

# Example resource information.
input.resourceType.name = "Cluster"
input.resource.name = "kafka-cluster"

The following table summarizes the supported resource types and operation names.

input.resourceType.name	input.operation.name
Cluster	ClusterAction
Cluster	Create
Cluster	Describe
Group	Read
Group	Describe
Topic	Alter
Topic	Delete
Topic	Describe
Topic	Read
Topic	Write