Once your Kafka clients are authenticated, Kafka needs to be able to decide what they can and cannot do. This is where Authorization comes in, controlled by Access Control Lists (ACL). ACL are what you expect them to be: User A can(‘t) do Operation B on Resource C from Host D. Please note that currently with the packaged
SimpleAclAuthorizercoming with Kafka, ACL are not implemented to have Groups rules or Regex-based rules. Therefore, each security rule has to be written in full (with the exception of the * wildcard).
ACL are great because they can help you prevent disasters. For example, you may have a topic that needs to be writeable from only a subset of clients or hosts. You want to prevent your average user from writing anything to these topics, hence preventing any data corruption or deserialization errors. ACLs are also great if you have some sensitive data and you need to prove to regulators that only certain applications or users can access that data.
He also has links to additional resources, which is helpful when you want to dig in further.