We currently have two important projects using rdkafka written in golang: purged and atskafka. It would be nice to have the option of exposing rdkafka metrics from those go projects without using an external exporter to get the best of both worlds out of the tradeoffs described in T237993#6104770.
To this end, we should create a go library to parse and expose the metrics returned by rdkafka. Programs written in other languages can take advantage of this library too by using an external exporter that we'll call prometheus-rdkafka-exporter.