Add per-listener connections.max.reauth.ms support

[ppatierno]

Apache Kafka provides the connections.max.reauth.ms [1] configuration parameter which can be set at broker level so applied on all listeners or even on a specific listener only.
Currently, Strimzi doesn't have support for specifying such a parameter at listener level because the listener. prefix is part of the list of the forbidden ones for the spec.kafka.config section.
The connections.max.reauth.ms would make sense for OAuth and SCRAM authentications enabled on a specific listener so we should add support in the authentication section of listeners via the KafkaListenerAuthenticationOAuth and KafkaListenerAuthenticationScramSha512 classes adding a new field for it.

[1] https://kafka.apache.org/documentation/#brokerconfigs_connections.max.reauth.ms

[fjbecerra]

hey, I'd like to work on this, may I be assigned, please?

[scholzj]

@ppatierno What is the plan for this? Do you have any idea how should the API look like?

[OneCricketeer]

What if there was a config section like

listenerOverrides:
  name: SASL_SSL  # optional: validate this exists as a configured listener 
  sasl_mechanism: OAUTHBEARER
  config: 
    connections.max.reauth.ms: 3600000

When templated will add

listener.name.sasl_ssl.oauthbearer.connections.max.reauth.ms=3600000

[scholzj]

@ppatierno ^^^ ???

I think it applies in general to all SASL listeners. So, I wonder if it should be just a property of the authentication? E.g.

listeners:
  #...
  - name: external
    port: 9094
    type: nodeport
    tls: false
    authentication:
      type: scram-sha-512
      maxReauthMs: 3600000

[scholzj]

(For type: custom authentication, I guess it can be already configured: https://github.com/strimzi/proposals/blob/1e6b49e5e6cbb001dff7adf2c3e3ec892487d2b7/032-custom_authentication_in_kafka_brokers.md?plain=1#L76)

[OneCricketeer]

should be just a property of the authentication

Any listener's port connection properties, including auth, should be able to be overridden.

Look at max.connections in Kafka docs, for example

[scholzj]

Any listener's port connection properties, including auth, should be able to be overridden.

The way we went with this so far is that you have the selected authentication types which enforce some properties. And then you have the custom type where you basically configure things your self. But outside of the custom type, some options are simply given by the other API fields / flags.

Look at max.connections in Kafka docs, for example

We already support this through specific fields. Look for maxConnections in https://strimzi.io/docs/operators/latest/full/configuring.html#type-GenericKafkaListenerConfiguration-schema-reference

[ppatierno]

I think the API proposed by Jakub makes more sense.

[fvaleri]

The connections.max.reauth.ms configuration only applies to SASL authentication. The KafkaClientAuthenticationTls should not have maxReauthMs property, even if setting a value would not have any effect.

[scholzj]

Triaged on 26.5.2022: There seem to be a different opinions on how the API should look like. So maybe we sould have a proposal to clarify all the concerns and alternatives.

[alexissellier]

What is the state of this issue. Does it need someone to take it ?

[scholzj]

I think it is waiting for someone to work on it. Given the API changes needed for this, there should be a proposal of how would it be done first (https://github.com/strimzi/proposals).