Doubler is an example app that demonstrates the use of github.com/mier85/go-sensor/instrumentation/instasarama to
instrument Kafka consumers and producers. It reads messages, containing integer values to the -in topic, multiplies
it by 2 and publishes the result to the topic defined by the -out flag.
To start a processor consuming messages from topic-a and publishing the result into topic-2a of a Kafka cluster
with brokers listening on localhost:9092 and localhost:9093, run:
go run . -in topic-a -out topic-2a localhost:9092 localhost:9093