Monitor and alert logs for denied ACL
=====================================

Aiven for Apache Kafka® uses access control lists (ACL) and user definitions in order to establish individual rights to produce or consume a topic. You read more about ACLs permission in the :doc:`dedicated documentation <../concepts/acl>`.

In cases of ACLs problems, an error ``io.aiven.kafka.auth.AivenAclAuthorizer`` is generated. 
The following log patterns can also be used to set up alerts checking for failed authentication and ACL evaluation.

Failed producer
---------------

A producer creates the following log in case the client has no privilege to write to a specific topic:

::

   HOSTNAME: kafka-pi-3141592-75
   SYSTEMD_UNIT: kafka.service
   MESSAGE: [2020-09-04 06:35:33,509] INFO [DENY] Auth request Write on Topic:nodejs-quickstart-kafka-topic by User test-kuser (io.aiven.kafka.auth.AivenAclAuthorizer)

Failed consumer
---------------

A consumer creates the following log in case the client has no privilege to describe a specific topic:

::

   HOSTNAME: kafka-pi-3141592-74
   SYSTEMD_UNIT: kafka.service
   MESSAGE: [2020-09-04 06:43:09,712] INFO [DENY] Auth request Describe on Topic:nodejs-quickstart-kafka-topic by User test-kuser (io.aiven.kafka.auth.AivenAclAuthorizer)

.. _valid-cert-with-invalid-key:

Valid certificate with invalid key
----------------------------------

A client creates the following log when using a valid certificate with an invalid key to perform a describe operation over a topic:

::

   HOSTNAME: kafka-pi-3141592-75
   SYSTEMD_UNIT: kafka.service
   MESSAGE: [2020-09-04 06:54:10,781] INFO [DENY] Auth request Describe on Topic:nodejs-quickstart-kafka-topic by Invalid CN=delete-user,OU=u6l6y9h1,O=kafka-pi-3141592 (io.aiven.kafka.auth.AivenAclAuthorizer)