Cannot publish

[politrons]

I´m trying to run Kafka and Zookepper using Docker following the steps defined here https://github.com/spotify/docker-kafka
But after run the docker command just as describe I don't understand for what for the export are, and I´m not able to publish anything pointing to localhost:9092` and I receive a timeout response.

This is the code of the publisher that I´m using https://github.com/politrons/Kafka/blob/master/src/main/scala/Producer.scala

Any idea if I´m doing something wrong?