From 83b32c3535afb566dbd9cc3036d05d84106df42b Mon Sep 17 00:00:00 2001
From: Asaf Mesika <asaf.mesika@gmail.com>
Date: Mon, 27 Nov 2023 17:46:44 +0200
Subject: [PATCH] Allow Prometheus exporter to add resource attributes to
 metric attributes (#3761)

Fixes #3705

## Changes

Allowing exporters (e.g. Prometheus exporter) to add the resource
attributes to each exported metric attributes
---
 CHANGELOG.md                                           |  3 +++
 .../compatibility/prometheus_and_openmetrics.md        | 10 +++++-----
 specification/metrics/sdk_exporters/prometheus.md      |  6 ++++++
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b21d69656a8..93e19aba28f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,9 @@ release.
 
 ### Metrics
 
+- Add optional configuration for Prometheus exporters to promote resource attributes to metric attributes
+  ([#3761](https://github.com/open-telemetry/opentelemetry-specification/pull/3761))
+
 ### Logs
 
 - Add definition for standard output log record exporter.
diff --git a/specification/compatibility/prometheus_and_openmetrics.md b/specification/compatibility/prometheus_and_openmetrics.md
index ecb74fc73dd..7f36beddf3c 100644
--- a/specification/compatibility/prometheus_and_openmetrics.md
+++ b/specification/compatibility/prometheus_and_openmetrics.md
@@ -385,11 +385,11 @@ OpenMetrics exemplar unless they would exceed the OpenMetrics
 
 In SDK Prometheus (pull) exporters, resource attributes SHOULD be converted to
 a single [`target_info` metric](https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#supporting-target-metadata-in-both-push-based-and-pull-based-systems)
-if the resource is not [empty](../resource/sdk.md#the-empty-resource);
-otherwise, they MUST be dropped, and MUST NOT be attached as labels to other
-metric families. The target_info metric MUST be an info-typed metric whose
-labels MUST include the resource attributes, and MUST NOT include any other
-labels. There MUST be at most one target_info metric exposed on an SDK
+if the resource is not [empty](../resource/sdk.md#the-empty-resource).
+The resource attributes MAY be copied to labels of exported metric families
+if required by the exporter configuration, or MUST be dropped. The target_info metric MUST be an info-typed
+metric whose labels MUST include the resource attributes, and MUST NOT include
+any other labels. There MUST be at most one target_info metric exposed on an SDK
 Prometheus endpoint.
 
 In the Collector's Prometheus pull and push (remote-write) exporters, it is
diff --git a/specification/metrics/sdk_exporters/prometheus.md b/specification/metrics/sdk_exporters/prometheus.md
index 8470a55694d..f72062e7c7a 100644
--- a/specification/metrics/sdk_exporters/prometheus.md
+++ b/specification/metrics/sdk_exporters/prometheus.md
@@ -25,3 +25,9 @@ A Prometheus Exporter MAY support [OpenMetrics Text
 Format](https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#openmetrics-text-format),
 including the
 [Exemplars](https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#exemplars).
+
+A Prometheus Exporter MAY offer configuration to add resource attributes as metric attributes.
+By default, it MUST NOT add any resource attributes as metric attributes.
+The configuration SHOULD allow the user to select which resource attributes to copy (e.g.
+include / exclude or regular expression based). Copied Resource attributes MUST NOT be
+excluded from target_info.