elasticsearch connector doesn't work - java.lang.NoClassDefFoundError: com/google/common/collect/ImmutableSet

[tirelibirefe]

Please look at the comprehensively explanation of the problem:
https://stackoverflow.com/questions/62015340/elasticsearch-connector-doesnt-work-java-lang-noclassdeffounderror-com-googl

"java.lang.NoClassDefFoundError: com/google/common/collect/ImmutableSet\n\tat io.searchbox.client.AbstractJestClient.<init>(AbstractJestClient.java:38)\n\tat io.searchbox.client.http.JestHttpClient.<init>(JestHttpClient.java:43)\n\tat io.searchbox.client.JestClientFactory.getObject(JestClientFactory.java:51)\n\tat io.confluent.connect.elasticsearch.jest.JestElasticsearchClient.<init>(JestElasticsearchClient.java:149)\n\tat io.confluent.connect.elasticsearch.jest.JestElasticsearchClient.<init>(JestElasticsearchClient.java:141)\n\tat io.confluent.connect.elasticsearch.ElasticsearchSinkTask.start(ElasticsearchSinkTask.java:122)\n\tat io.confluent.connect.elasticsearch.ElasticsearchSinkTask.start(ElasticsearchSinkTask.java:51)\n\tat org.apache.kafka.connect.runtime.WorkerSinkTask.initializeAndStart(WorkerSinkTask.java:305)\n\tat org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:193)\n\tat org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:184)\n\tat org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:234)\n\tat java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)\n\tat java.util.concurrent.FutureTask.run(FutureTask.java:266)\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)\n\tat java.lang.Thread.run(Thread.java:748)\n"

Please advise, am I missing something or anything else?

[tirelibirefe]

Adding missing guava-20.0.jar to /opt/kafka/libs/ at worker node container fixed the problem. My environment is;
Strimzi 0.18
Kafka 2.5.0

COPY guava-20.0.jar /opt/kafka/libs/

[datumgeek]

Adding missing guava-20.0.jar to /opt/kafka/libs/ at worker node container fixed the problem for me :) :)

[shri3k]

I ran into this too and was banging my head for some time. And just an FYI why this happens is I think it's because you possibly downloaded Kafka from Apache's site as opposed to using Confluent's version. I didn't see guava included in Apache's version in their /libs/ directory but did see it in Confluent's docker images.
And last thing, you can get guava from this page but I was able to just do find / -name guava* and copy that from one of the other folder which already had that jar file available there.