Automatically setup basic otel/prometheus metrics about function-sdk-go

[phisco]

for sure I'd go with prometheus metrics, https://github.com/grpc-ecosystem/go-grpc-middleware/tree/main/providers/prometheus feels like the suggested way to do that.

[negz]

@phisco I think there's an otel equivalent that gives traces and metrics. Could be worth considering. To be clear, the metrics are exposed in Prom-style /metrics, it's just a different library doing it. That said, last time I checked the otel metrics packages were pretty unstable API wise.

[phisco]

yeah, not so straightforward: https://github.com/grpc-ecosystem/go-grpc-middleware/blob/71d7422112b1d7fadd4b8bf12a6f33ba6d22e98e/examples/server/main.go#L77 .