Need a way to extract bootstrap servers after mock servers are created

[CodechCFA]

Description

librdkafka allows creating mock brokers for testing purposes by passing test.mock.num.brokers as a configuration parameter. The problem is we need the bootstrap server addresses it creates in order to produce to them or consume from them but this library provides no way to extract them.

How to reproduce

kafkaProducer, err := kafka.NewProducer(&kafka.ConfigMap{"test.mock.num.brokers": 3})

consumer, err := kafka.NewConsumer(&kafka.ConfigMap{"bootstrap.servers":   ?})

[edenhill]

Right, we would need to add a Go function for rd_kafka_mock_cluster_bootstraps().

[SourceFellows]

I created a "fix"/pull request for something like that: #729

We use the implementation to do "isolated integration testing" for our application.