ACLs are not removed from cluster with FileBackend

[akselh]

I just found out that KTB is not deleting obsolete ACLs. I did a little bit of investigation and it seems that the problem was introduced in https://github.com/kafka-ops/kafka-topology-builder/pull/77. Not immediately sure how the problem should be fixed though...

1

These changes (was ClusterState, now in BackendController) seems to be one of the problems: https://github.com/kafka-ops/kafka-topology-builder/blob/1fcda5b84844d76daac21773f0060961047ed6e2/src/main/java/com/purbon/kafka/topology/BackendController.java#L55

The semantics of method createOrOpen for FileBackend is actually createOrOverwrite. :-) So no bindings is loaded from .cluster-state and all ACLs from topology are marked for creation (and never any for deletion).

FileWriter have to be initialized with append=true to not overwrite/delete the file contents. But changing to append=true have other undesired effects like not removing deleted ACLs from the file.

2

The bindings sent to buildUpdateBindingsActions should be the ones from .cluster-state not the bindings from the actions: https://github.com/kafka-ops/kafka-topology-builder/blob/1fcda5b84844d76daac21773f0060961047ed6e2/src/main/java/com/purbon/kafka/topology/AccessControlManager.java#L68

3

The handling of bindings in ExecutionPlan also looks a bit weird: https://github.com/kafka-ops/kafka-topology-builder/blob/1fcda5b84844d76daac21773f0060961047ed6e2/src/main/java/com/purbon/kafka/topology/ExecutionPlan.java#L70 Should maybe only add to bindings if !(action instanceof ClearBindings)?

[akselh]

This issue also makes running with --dryRun remove all contents from .cluster-state