Stabilize OTLP -> Prometheus: add otel_scope_* labels

[johannaojeling]

As part of the effort to stabilize OTLP -> Prometheus conversion, instrumentation scope labels should be added to metric points in the Prometheus exporter, per spec.

Currently, in opentelemetry-exporter-prometheus, metrics are iterated from scope_metrics, but label construction uses only point attributes and does not include scope_metrics.scope fields.

As a result, exported metrics currently miss:

• otel_scope_name
• otel_scope_version
• otel_scope_schema_url
• otel_scope_<attr> labels

Related:

• [prometheus] Stabilize OTLP -> Prometheus: Instrumentation Scope opentelemetry-specification#4918
• OTLP to Prometheus: Stabilize Instrumentation Scope opentelemetry-specification#5052 (comment)

[johannaojeling]

@ArthurSens it seems like this will be addressed already in #5123, or can you see anything missing from that PR?

[ArthurSens]

Oh nice. I don't know Python well enough to review the PR 😅. From what is documented in text, looks correct :)

[johannaojeling]

Okay great, I'll close this issue since it's going to be addressed in that PR (which fixes #5112) 🙂