spanmetricsprocessor: Set resource attributes where possible

[gouthamve]

Component(s)

processor/spanmetrics

Is your feature request related to a problem? Please describe.

I was using the spanmetricsprocessor with prometheusexporter and was surprised to find the service_name as a label instead of job.

Digging deeper, this is because the processor only sets metric attributes but not resource attributes.

Describe the solution you'd like

I think we should set resource attributes if we are aggregating by a resource attribute.

For example, if we are aggregating by service.name and service.instance.id, the dimensions in the metrics emitted should be part of resource attributes and not metric attributes.

Describe alternatives you've considered

Use the transform processor to move the metric attributes to resource attributes.

Additional context

No response

[github-actions]

Pinging code owners:

• processor/spanmetrics: @albertteoh

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[kovrus]

@gouthamve @albertteoh I'll implement it only for the spanmetrics connector, I'll keep the processor as it is.

[github-actions]

Pinging code owners for connector/spanmetrics: @albertteoh. See Adding Labels via Comments if you do not have permissions to add labels yourself.