Using resource attributes as tags in the dimensions

[pedro-stanaka]

Summary

The metric translator has the option to use ResourceAttributesAsTags, but it is not using that option at all when converting metrics. Is that expected?

If it is a bug, would you be open to a PR?

[ringerc]

Where does this actually take effect?

I've traced resource_attributes_as_tags from the DD exporter code:

https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/50794afa6b2898515cdab0df2da976716f95e0dd/exporter/datadogexporter/config.go#L239

https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/50794afa6b2898515cdab0df2da976716f95e0dd/exporter/datadogexporter/metrics_exporter.go#L68

to this repo, where it's set as:

opentelemetry-mapping-go/pkg/otlp/metrics/config.go

Line 99 in 5432be0

func WithResourceAttributesAsTags() TranslatorOption {

That sets

opentelemetry-mapping-go/pkg/otlp/metrics/config.go

Line 101 in 5432be0

t.ResourceAttributesAsTags = true

t.ResourceAttributesAsTags on the translatorConfig struct. But this does not appear to be referenced anywhere.

So how does it have any effect?

[ringerc]

It looks like the work is really done by https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/pkg/resourcetotelemetry via factory.go in https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/50794afa6b2898515cdab0df2da976716f95e0dd/exporter/datadogexporter/factory.go#L297

so the code in this repo for ResourceAttributesAsTags is probably legacy/meaningless/unfinished.

[ringerc]

Datadog does have docs on these mappings, albeit outdated and incomplete:

• https://docs.datadoghq.com/opentelemetry/guide/semantic_mapping/
• https://docs.datadoghq.com/opentelemetry/guide/metrics_mapping/

They aren't easily found though, they're only linked in a "see also" down the bottom of a few of the other otel exporter articles. They're not linked in any of the tagging docs like:

• https://docs.datadoghq.com/getting_started/tagging/
• https://docs.datadoghq.com/getting_started/tagging/using_tags
• https://docs.datadoghq.com/getting_started/tagging/assigning_tags
• https://docs.datadoghq.com/getting_started/tagging/unified_service_tagging
• https://docs.datadoghq.com/opentelemetry/otel_collector_datadog_exporter/?tab=onahost (except in the footer pile of articles)
• https://www.datadoghq.com/blog/tagging-best-practices/

so it's hard to figure out how the datadog exporter for the opentelemetry collector maps the attribute service.name to the datadog service tag, the cloud.availability_zone attribute to zone (not for some reason availability-zone), etc.

There is a mapping in this repo at https://github.com/DataDog/opentelemetry-mapping-go/tree/main/pkg/otlp/attributes/attributes.go ; it has a bunch of mappings not covered in the above docs, but that's where it's done.

[songy23]

The particular config is removed in #219.