Add WithResourceAttributes option

CHANGELOG.md

@@ -8,6 +8,10 @@ OpenTelemetry Go Automatic Instrumentation adheres to [Semantic Versioning](http
 
 ## [Unreleased]
 
+### Added
+
+- Add `WithResourceAttributes` `InstrumentationOption` to configure `Instrumentation` to add additional resource attributes. ([#522](https://github.com/open-telemetry/opentelemetry-go-instrumentation/pull/522))
+
 ### Changed
 
 - The instrumentation scope name for the `database/sql` instrumentation is now `go.opentelemtry.io/auto/database/sql`. (#507)

instrumentation.go

@@ -27,12 +27,14 @@ import (
 	"github.com/go-logr/logr"
 	"github.com/go-logr/stdr"
 	"github.com/go-logr/zapr"
+	"go.uber.org/zap"
+
 	"go.opentelemetry.io/contrib/exporters/autoexport"
+	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
 	"go.opentelemetry.io/otel/sdk/resource"
 	"go.opentelemetry.io/otel/sdk/trace"
 	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
-	"go.uber.org/zap"
 
 	"go.opentelemetry.io/auto/internal/pkg/instrumentation"
 	"go.opentelemetry.io/auto/internal/pkg/opentelemetry"
@@ -163,10 +165,11 @@ type InstrumentationOption interface {
 }
 
 type instConfig struct {
-	sampler     trace.Sampler
-	traceExp    trace.SpanExporter
-	target      process.TargetArgs
-	serviceName string
+	sampler            trace.Sampler
+	traceExp           trace.SpanExporter
+	target             process.TargetArgs
+	serviceName        string
+	additionalResAttrs []attribute.KeyValue
 }
 
 func newInstConfig(ctx context.Context, opts []InstrumentationOption) (instConfig, error) {
@@ -239,14 +242,22 @@ func (c instConfig) res() *resource.Resource {
 		runVer, runtime.GOOS, runtime.GOARCH,
 	)
 
-	return resource.NewWithAttributes(
-		semconv.SchemaURL,
+	attrs := []attribute.KeyValue{
 		semconv.ServiceNameKey.String(c.serviceName),
 		semconv.TelemetrySDKLanguageGo,
 		semconv.TelemetryAutoVersionKey.String(Version()),
 		semconv.ProcessRuntimeName(runName),
 		semconv.ProcessRuntimeVersion(runVer),
 		semconv.ProcessRuntimeDescription(runDesc),
+	}
+
+	if len(c.additionalResAttrs) > 0 {
+		attrs = append(attrs, c.additionalResAttrs...)
+	}
+
+	return resource.NewWithAttributes(
+		semconv.SchemaURL,
+		attrs...,
 	)
 }
 
@@ -342,36 +353,45 @@ func WithEnv() InstrumentationOption {
 			c.traceExp, e = autoexport.NewSpanExporter(ctx)
 			err = errors.Join(err, e)
 		}
-		if v, ok := lookupServiceName(); ok {
-			c.serviceName = v
+		if name, attrs, ok := lookupResourceData(); ok {
+			c.serviceName = name
+			c.additionalResAttrs = append(c.additionalResAttrs, attrs...)
 		}
 		return c, err
 	})
 }
 
-func lookupServiceName() (string, bool) {
+func lookupResourceData() (string, []attribute.KeyValue, bool) {
 	// Prioritize OTEL_SERVICE_NAME over OTEL_RESOURCE_ATTRIBUTES value.
+	svcName := ""
 	if v, ok := lookupEnv(envServiceNameKey); ok {
-		return v, ok
+		svcName = v
 	}
 
 	v, ok := lookupEnv(envResourceAttrKey)
 	if !ok {
-		return "", false
+		return svcName, nil, svcName != ""
 	}
 
+	var attrs []attribute.KeyValue
 	for _, keyval := range strings.Split(strings.TrimSpace(v), ",") {
 		key, val, found := strings.Cut(keyval, "=")
 		if !found {
 			continue
 		}
 		key = strings.TrimSpace(key)
 		if key == string(semconv.ServiceNameKey) {
-			return strings.TrimSpace(val), true
+			svcName = strings.TrimSpace(val)
+		} else {
+			attrs = append(attrs, attribute.String(key, strings.TrimSpace(val)))
 		}
 	}
 
-	return "", false
+	if svcName == "" {
+		return "", nil, false
+	}
+
+	return svcName, attrs, true
 }
 
 // WithTraceExporter returns an [InstrumentationOption] that will configure an
@@ -396,3 +416,12 @@ func WithSampler(sampler trace.Sampler) InstrumentationOption {
 		return c, nil
 	})
 }
+
+// WithResourceAttributes returns an [InstrumentationOption] that will configure
+// an [Instrumentation] to add the provided attributes to the OpenTelemetry resource.
+func WithResourceAttributes(attrs ...attribute.KeyValue) InstrumentationOption {
+	return fnOpt(func(_ context.Context, c instConfig) (instConfig, error) {
+		c.additionalResAttrs = append(c.additionalResAttrs, attrs...)
+		return c, nil
+	})
+}

instrumentation_test.go

@@ -21,6 +21,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/otel/attribute"
 	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
 )
 
@@ -127,6 +129,49 @@ func TestOptionPrecedence(t *testing.T) {
 	})
 }
 
+func TestWithResourceAttributes(t *testing.T) {
+	t.Run("By Code", func(t *testing.T) {
+		attr1 := semconv.K8SContainerName("test_container_name")
+		attr2 := semconv.K8SPodName("test_pod_name")
+		attr3 := semconv.K8SNamespaceName("test_namespace_name")
+
+		c, err := newInstConfig(context.Background(), []InstrumentationOption{WithResourceAttributes(attr1, attr2), WithResourceAttributes(attr3)})
+		require.NoError(t, err)
+		assert.Equal(t, []attribute.KeyValue{attr1, attr2, attr3}, c.additionalResAttrs)
+	})
+
+	t.Run("By Env", func(t *testing.T) {
+		nameAttr := semconv.ServiceName("test_service")
+		attr2 := semconv.K8SPodName("test_pod_name")
+		attr3 := semconv.K8SNamespaceName("test_namespace_name")
+
+		mockEnv(t, map[string]string{
+			"OTEL_RESOURCE_ATTRIBUTES": fmt.Sprintf("%s=%s,%s=%s,%s=%s", nameAttr.Key, nameAttr.Value.AsString(), attr2.Key, attr2.Value.AsString(), attr3.Key, attr3.Value.AsString()),
+		})
+
+		c, err := newInstConfig(context.Background(), []InstrumentationOption{WithEnv()})
+		require.NoError(t, err)
+		assert.Equal(t, nameAttr.Value.AsString(), c.serviceName)
+		assert.Equal(t, []attribute.KeyValue{attr2, attr3}, c.additionalResAttrs)
+	})
+
+	t.Run("By Code and Env", func(t *testing.T) {
+		nameAttr := semconv.ServiceName("test_service")
+		attr2 := semconv.K8SPodName("test_pod_name")
+		attr3 := semconv.K8SNamespaceName("test_namespace_name")
+
+		mockEnv(t, map[string]string{
+			"OTEL_RESOURCE_ATTRIBUTES": fmt.Sprintf("%s=%s,%s=%s", nameAttr.Key, nameAttr.Value.AsString(), attr2.Key, attr2.Value.AsString()),
+		})
+
+		// Use WithResourceAttributes to config the additional resource attributes
+		c, err := newInstConfig(context.Background(), []InstrumentationOption{WithEnv(), WithResourceAttributes(attr3)})
+		require.NoError(t, err)
+		assert.Equal(t, nameAttr.Value.AsString(), c.serviceName)
+		assert.Equal(t, []attribute.KeyValue{attr2, attr3}, c.additionalResAttrs)
+	})
+}
+
 func mockEnv(t *testing.T, env map[string]string) {
 	orig := lookupEnv
 	t.Cleanup(func() { lookupEnv = orig })