feat(datadog): create exporter module for datadog

[jdrouet]

Signed-off-by: Jérémie Drouet jeremie.drouet@gmail.com

[jdrouet]

Well, at this point, I need async-await to use datadog-client to send the series.
I've tried to use the one embedded with actix-web (actix-rt + futures) and I didn't manage yet.
One solution could be to add tokio but this would be a duplicate with actix-rt. Upgrading actix-web to its beta version (did it on catapulte and it works pretty well) would probably fix it (it relies on tokio).
Any opinion @bpetit ?

[bpetit]

Hi ! Thanks for the PR ! 🥳

I'm not sure I understand why you need async.

I see in the code it's related to waiting the answer from datadog after posting the data. Is this mandatory from datadog to wait for that answer asynchronously ?

I mean we use async on prometheus because it is pull mode. Even in that context, I'm not convinced it's the best way to do it as an exporter should not be scrapped by many clients nor very often (not more that every few seconds). So async is kind of a burden for the binary, where it doesn't bring much benefits.

For push mode exporters I'd imagine that we could avoid using async, but maybe it's a hard requirement here ?

[jdrouet]

The library datadog-client uses async-await which could be better in a context where tokio is already loaded.
In added ureq which is a blocking alternative to reqwest, so should be good now.

[bpetit]

Thanks ! I'm working on it to merge with latest changes in main and use the MetricGenerator from @uggla to get metrics.