No LoginModule found for ScramLoginModule

[KatePopkova]

Hello,

We have updated Zeebe version (from 0.26 to 1.2.9) including Kafka exporter version (from 2.0.0 to 3.0.0) and started to it for our projects. The problem is new version of Kafka exporter does not work for now. You can see a trace log in the screenshot:

Therefore I cannot find any messages in a Kafka topic where Kafka exporter must produce.

We have managed to find a ticket (#78) where @npepinpe advised to put JAR file into /usr/local/zeebe/lib path and JAR is placed in correct path for now but there is still the same issue.

It seems there is no same issue in the previous version of the Kafka exporter (that was compatible for earlier Zeebe version) and sasl.jaas.config is the same for both (older and newer) Zeebe versions:

sasl.jaas.config = org.apache.kafka.common.security.scram.ScramLoginModule required username='user' password='user_pwd'

There is one more thing. It seams there is no ScramLoginModule class into zeebe-kafka-exporter-3.0.0-jar-with-dependencies.jar:

find . -name "Scram*.class" -type file
./org/apache/kafka/common/security/scram/ScramCredentialCallback.class
./org/apache/kafka/common/security/scram/internals/ScramCredentialUtils.class
./org/apache/kafka/common/security/scram/internals/ScramMechanism.class
./org/apache/kafka/common/security/scram/internals/ScramServerCallbackHandler.class
./org/apache/kafka/common/security/scram/ScramCredential.class
./org/apache/kafka/common/security/scram/ScramExtensionsCallback.class

Kafka exporter uses kafka-clients v. 2.8.0 (https://github.com/camunda-community-hub/zeebe-kafka-exporter/blob/3.0.0/pom.xml#L47), but kafka-clients includes that class:

find . -name "Scram*.class" -type file
./org/apache/kafka/clients/admin/ScramCredentialInfo.class
./org/apache/kafka/clients/admin/ScramMechanism.class
./org/apache/kafka/common/security/scram/ScramCredentialCallback.class
./org/apache/kafka/common/security/scram/internals/ScramExtensions.class
./org/apache/kafka/common/security/scram/internals/ScramMessages$AbstractScramMessage.class
./org/apache/kafka/common/security/scram/internals/ScramMessages$ClientFinalMessage.class
./org/apache/kafka/common/security/scram/internals/ScramMessages$ServerFinalMessage.class
./org/apache/kafka/common/security/scram/internals/ScramSaslServerProvider.class
./org/apache/kafka/common/security/scram/internals/ScramSaslServer$ScramSaslServerFactory.class
./org/apache/kafka/common/security/scram/internals/ScramFormatter.class
./org/apache/kafka/common/security/scram/internals/ScramSaslClient.class
./org/apache/kafka/common/security/scram/internals/ScramSaslClient$1.class
./org/apache/kafka/common/security/scram/internals/ScramSaslClient$ScramSaslClientFactory.class
./org/apache/kafka/common/security/scram/internals/ScramSaslServer$State.class
./org/apache/kafka/common/security/scram/internals/ScramSaslServer.class
./org/apache/kafka/common/security/scram/internals/ScramCredentialUtils.class
./org/apache/kafka/common/security/scram/internals/ScramSaslServer$1.class
./org/apache/kafka/common/security/scram/internals/ScramMechanism.class
./org/apache/kafka/common/security/scram/internals/ScramSaslClientProvider.class
./org/apache/kafka/common/security/scram/internals/ScramSaslClient$State.class
./org/apache/kafka/common/security/scram/internals/ScramMessages.class
./org/apache/kafka/common/security/scram/internals/ScramMessages$ClientFirstMessage.class
./org/apache/kafka/common/security/scram/internals/ScramServerCallbackHandler.class
./org/apache/kafka/common/security/scram/internals/ScramMessages$ServerFirstMessage.class
./org/apache/kafka/common/security/scram/ScramCredential.class
./org/apache/kafka/common/security/scram/ScramExtensionsCallback.class
./org/apache/kafka/common/security/scram/ScramLoginModule.class

Could you, please, help us to sort this issue out?
Thank you in advance.

[npepinpe]

I think I might have some idea of why this is happening, but I haven't tested it. It might be that the shade plugin is removing what it sees as unused classes, which is why it ends up missing at runtime. It might be interesting to swap out the shade plugin for the assembly plugin instead. That's a little more verbose, but it's also easier to understand what the assembly plugin does, as opposed to the shade plugin.

I unfortunately don't really have the time to maintain this extension anymore, but I'm happy to review any PRs and trigger a release until a new maintainer is found/takes over.

By the way, thanks for the research and well explained issue, what you wrote helped me immediately pin point a lead 👍 Still remains to be seen if I'm right, but I think it's a good start 🙂

[KatePopkova]

@npepinpe Hello Nicolas,
Thank you for your advice. I am not build a new JAR file as you advised before with the another plugin but I have done a workaround. I have just tried to put JAR of kafka-clients near Kafka exporter JAR. But it does not help and the issue is still here. If you have more ideas about it, let me know, please.