Migrate prometheus exporter to otlptranslator

CHANGELOG.md

@@ -50,6 +50,14 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Change `AssertEqual` in `go.opentelemetry.io/otel/log/logtest` to accept `TestingT` in order to support benchmarks and fuzz tests. (#6908)
 - Change `SDKProcessorLogQueueCapacity`, `SDKProcessorLogQueueSize`, `SDKProcessorSpanQueueSize`, and `SDKProcessorSpanQueueCapacity` in `go.opentelemetry.io/otel/semconv/v1.36.0/otelconv` to use a `Int64ObservableUpDownCounter`. (#7041)
+- Change `go.opentelemetry.io/otel/exporters/prometheus` to no longer deduplicate suffixes when UTF8 is enabled.
+  It is recommended to disable unit and counter suffixes in the exporter, and manually add suffixes if you rely
+  on the existing behavior. (#7044)
+
+### Fixed
+
+- Fix `go.opentelemetry.io/otel/exporters/prometheus` to properly handle unit suffixes when the unit is in brackets.
+  E.g. `{spans}`. (#7044)
 
 <!-- Released section -->
 <!-- Don't change this section unless doing release -->

exporters/prometheus/config.go

@@ -4,11 +4,9 @@
 package prometheus // import "go.opentelemetry.io/otel/exporters/prometheus"
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/common/model"
 
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/internal/global"
@@ -139,17 +137,6 @@ func WithoutScopeInfo() Option {
 // have special behavior based on their name.
 func WithNamespace(ns string) Option {
 	return optionFunc(func(cfg config) config {
-		if model.NameValidationScheme != model.UTF8Validation { // nolint:staticcheck // We need this check to keep supporting the legacy scheme.
-			logDeprecatedLegacyScheme()
-			// Only sanitize if prometheus does not support UTF-8.
-			ns = model.EscapeName(ns, model.NameEscapingScheme)
-		}
-		if !strings.HasSuffix(ns, "_") {
-			// namespace and metric names should be separated with an underscore,
-			// adds a trailing underscore if there is not one already.
-			ns = ns + "_"
-		}
-
 		cfg.namespace = ns
 		return cfg
 	})

exporters/prometheus/config_test.go

@@ -113,17 +113,17 @@ func TestNewConfig(t *testing.T) {
 			},
 			wantConfig: config{
 				registerer: prometheus.DefaultRegisterer,
-				namespace:  "test_",
+				namespace:  "test",
 			},
 		},
 		{
 			name: "with namespace with trailing underscore",
 			options: []Option{
-				WithNamespace("test_"),
+				WithNamespace("test"),
 			},
 			wantConfig: config{
 				registerer: prometheus.DefaultRegisterer,
-				namespace:  "test_",
+				namespace:  "test",
 			},
 		},
 		{
@@ -133,7 +133,7 @@ func TestNewConfig(t *testing.T) {
 			},
 			wantConfig: config{
 				registerer: prometheus.DefaultRegisterer,
-				namespace:  "test/_",
+				namespace:  "test/",
 			},
 		},
 	}