DefaultElasticsearch returns a configuration for an Elasticsearch server with default settings listening on port 9200.

DefaultKafka returns a configuration for a Kafka server with default settings listening on port 9092.

DefaultLogstash returns a configuration for a Logstash server with default settings listening on port 5044.

Down calls docker-compose down on the given container configurations and returns the result.

Up calls docker-compose up on the given container configurations and returns the resulting standard output and its result.

TestImageConfig is a wrapper to make the internal representation of the test images and configuration opaque to callers, since we will probably want to change them as we expand to cover more environments / support more features.