@MrLotU this would be an awesome addition to the ecosystem. its in-line with our published focus areas and a great place to start given how useful prometheus has proven itself to be
i would like however, to first define an abstract metrics API (similar to the one we are defining for logging) which will allow application owners to plug-in different metrics backends, and library developers to emit metrics without getting in the way. the reasoning is summarized in here, that post is about logging but the same is true for metrics as well
to avoid loosing momentum, i suggest we parallelize the two efforts, but we should be prepared to retrofit the prometheus implementation on top of the generic API once that is finalized to achieve consistency in the ecosystem. your experience in developing prometheus implementation can also help influence and direct the generic API and vice versa