Add SDK.Resource() to otelconf/v0.3.0

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
+- Add `Resource` method to `SDK` in `go.opentelemetry.io/contrib/otelconf/v0.3.0` to expose the resolved SDK resource from declarative configuration. (#8660)
 - Configuration file can now be set via `OTEL_CONFIG_FILE` in `go.opentelemetry.io/contrib/otelconf`. (#8639)
 - Added support for `service` resource detector in `go.opentelemetry.io/contrib/otelconf`. (#8674)
 - Added support for `attribute_count_limit` and `attribute_value_length_limit` in tracer provider configuration in `go.opentelemetry.io/contrib/otelconf`. (#8687)

otelconf/v0.3.0/config.go

@@ -16,6 +16,7 @@ import (
 	noopmetric "go.opentelemetry.io/otel/metric/noop"
 	sdklog "go.opentelemetry.io/otel/sdk/log"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
+	sdkresource "go.opentelemetry.io/otel/sdk/resource"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/trace"
 	nooptrace "go.opentelemetry.io/otel/trace/noop"
@@ -52,6 +53,7 @@ type SDK struct {
 	meterProvider  metric.MeterProvider
 	tracerProvider trace.TracerProvider
 	loggerProvider log.LoggerProvider
+	resource       *sdkresource.Resource
 	shutdown       shutdownFunc
 }
 
@@ -70,6 +72,16 @@ func (s *SDK) LoggerProvider() log.LoggerProvider {
 	return s.loggerProvider
 }
 
+// Resource returns a copy of the resolved SDK resource configured in this SDK.
+// The copy preserves the immutability of the SDK-owned resource.
+func (s *SDK) Resource() *sdkresource.Resource {
+	if s.resource == nil {
+		return nil
+	}
+	res := *s.resource
+	return &res
+}
+
 // Shutdown calls shutdown on all configured providers.
 func (s *SDK) Shutdown(ctx context.Context) error {
 	return s.shutdown(ctx)
@@ -79,6 +91,7 @@ var noopSDK = SDK{
 	loggerProvider: nooplog.LoggerProvider{},
 	meterProvider:  noopmetric.MeterProvider{},
 	tracerProvider: nooptrace.TracerProvider{},
+	resource:       sdkresource.Empty(),
 	shutdown:       func(context.Context) error { return nil },
 }
 
@@ -115,6 +128,7 @@ func NewSDK(opts ...ConfigurationOption) (SDK, error) {
 		meterProvider:  mp,
 		tracerProvider: tp,
 		loggerProvider: lp,
+		resource:       r,
 		shutdown: func(ctx context.Context) error {
 			return errors.Join(mpShutdown(ctx), tpShutdown(ctx), lpShutdown(ctx))
 		},

otelconf/v0.3.0/config_resource_test.go

@@ -0,0 +1,70 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package otelconf
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/otel/attribute"
+	sdkresource "go.opentelemetry.io/otel/sdk/resource"
+)
+
+func TestSDKResource(t *testing.T) {
+	t.Run("returns nil for zero value sdk", func(t *testing.T) {
+		var sdk SDK
+		assert.Nil(t, sdk.Resource())
+	})
+
+	t.Run("returns resource even when providers are not configured", func(t *testing.T) {
+		sdk, err := NewSDK(
+			WithOpenTelemetryConfiguration(OpenTelemetryConfiguration{
+				Resource: &Resource{
+					Attributes: []AttributeNameValue{
+						{Name: "service.name", Value: "collector"},
+					},
+				},
+			}),
+		)
+		assert.NoError(t, err)
+
+		res := sdk.Resource()
+		assert.NotNil(t, res)
+		assert.Contains(t, res.Attributes(), attribute.String("service.name", "collector"))
+	})
+
+	t.Run("returns empty resource for disabled sdk", func(t *testing.T) {
+		sdk, err := NewSDK(
+			WithOpenTelemetryConfiguration(OpenTelemetryConfiguration{
+				Disabled: ptr(true),
+			}),
+		)
+		assert.NoError(t, err)
+		assert.NotNil(t, sdk.Resource())
+		assert.Empty(t, sdk.Resource().Attributes())
+	})
+
+	t.Run("returns a defensive copy", func(t *testing.T) {
+		sdk, err := NewSDK(
+			WithOpenTelemetryConfiguration(OpenTelemetryConfiguration{
+				Resource: &Resource{
+					Attributes: []AttributeNameValue{
+						{Name: "service.name", Value: "collector"},
+					},
+				},
+			}),
+		)
+		assert.NoError(t, err)
+
+		res := sdk.Resource()
+		assert.NotNil(t, res)
+
+		newRes := sdkresource.NewSchemaless(attribute.String("service.name", "mutated"))
+		*res = *newRes
+
+		assert.Contains(t, res.Attributes(), attribute.String("service.name", "mutated"))
+		assert.Contains(t, sdk.Resource().Attributes(), attribute.String("service.name", "collector"))
+		assert.NotContains(t, sdk.Resource().Attributes(), attribute.String("service.name", "mutated"))
+	})
+}