Change resource.New() to use functional options; add builtin attributes for (host.*, telemetry.sdk.*) (#1235)

* Add a resource.Configure() with functional options

* Add a changelog

* Add tests for builtin resources

* Rename to WithoutBuiltin

* Add new test; restore environment after tests

* Apply feedback

* Apply suggestions from code review

❤️

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

* Comment edits

* Rename New, former method NewFromAttributes

* NewFromAttributes->NewWithAttributes

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -35,6 +35,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Move the `go.opentelemetry.io/otel/api/global` package to `go.opentelemetry.io/otel/global`. (#1262)
 - Rename correlation context header from `"otcorrelations"` to `"baggage"` to match the OpenTelemetry specification. (#1267)
 - Fix `Code.UnmarshalJSON` to work with valid json only. (#1276)
+- The `resource.New()` method changes signature to support builtin attributes and functional options, including `telemetry.sdk.*` and
+  `host.name` semantic conventions; the former method is renamed `resource.NewWithAttributes`. (#1235)
 
 ### Removed
 

example/otel-collector/main.go

@@ -41,6 +41,7 @@ import (
 // Initializes an OTLP exporter, and configures the corresponding trace and
 // metric providers.
 func initProvider() func() {
+	ctx := context.Background()
 
 	// If the OpenTelemetry Collector is running on a local cluster (minikube or
 	// microk8s), it should be accessible through the NodePort service at the
@@ -54,13 +55,18 @@ func initProvider() func() {
 	)
 	handleErr(err, "failed to create exporter")
 
+	res, err := resource.New(ctx,
+		resource.WithAttributes(
+			// the service name used to display traces in backends
+			semconv.ServiceNameKey.String("test-service"),
+		),
+	)
+	handleErr(err, "failed to create resource")
+
 	bsp := sdktrace.NewBatchSpanProcessor(exp)
 	tracerProvider := sdktrace.NewTracerProvider(
 		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
-		sdktrace.WithResource(resource.New(
+		sdktrace.WithResource(res),
-			// the service name used to display traces in backends
-			semconv.ServiceNameKey.String("test-service"),
-		)),
 		sdktrace.WithSpanProcessor(bsp),
 	)
 
@@ -80,7 +86,6 @@ func initProvider() func() {
 	pusher.Start()
 
 	return func() {
-		ctx := context.Background()
 		handleErr(tracerProvider.Shutdown(ctx), "failed to shutdown provider")
 		handleErr(exp.Shutdown(ctx), "failed to stop exporter")
 		pusher.Stop() // pushes any last exports to the receiver

exporters/metric/prometheus/example_test.go

@@ -37,10 +37,20 @@ import (
 // TODO: Address this issue.
 
 func ExampleNewExportPipeline() {
+	// Create a resource, with builtin attributes plus R=V.
+	res, err := resource.New(
+		context.Background(),
+		resource.WithoutBuiltin(), // Test-only!
+		resource.WithAttributes(label.String("R", "V")),
+	)
+	if err != nil {
+		panic(err)
+	}
+
 	// Create a meter
 	exporter, err := prometheus.NewExportPipeline(
 		prometheus.Config{},
-		pull.WithResource(resource.New(label.String("R", "V"))),
+		pull.WithResource(res),
 	)
 	if err != nil {
 		panic(err)

exporters/metric/prometheus/prometheus_test.go

@@ -39,7 +39,7 @@ func TestPrometheusExporter(t *testing.T) {
 			DefaultHistogramBoundaries: []float64{-0.5, 1},
 		},
 		pull.WithCachePeriod(0),
-		pull.WithResource(resource.New(label.String("R", "V"))),
+		pull.WithResource(resource.NewWithAttributes(label.String("R", "V"))),
 	)
 	require.NoError(t, err)
 

exporters/otlp/internal/transform/metric_test.go

@@ -320,7 +320,7 @@ func TestRecordAggregatorIncompatibleErrors(t *testing.T) {
 	makeMpb := func(kind aggregation.Kind, agg aggregation.Aggregation) (*metricpb.Metric, error) {
 		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, otel.Int64NumberKind)
 		labels := label.NewSet()
-		res := resource.New()
+		res := resource.Empty()
 		test := &testAgg{
 			kind: kind,
 			agg:  agg,
@@ -357,7 +357,7 @@ func TestRecordAggregatorUnexpectedErrors(t *testing.T) {
 	makeMpb := func(kind aggregation.Kind, agg aggregation.Aggregation) (*metricpb.Metric, error) {
 		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, otel.Int64NumberKind)
 		labels := label.NewSet()
-		res := resource.New()
+		res := resource.Empty()
 		return Record(export.NewRecord(&desc, &labels, res, agg, intervalStart, intervalEnd))
 	}
 

exporters/otlp/internal/transform/resource_test.go

@@ -40,7 +40,7 @@ func TestEmptyResource(t *testing.T) {
 func TestResourceAttributes(t *testing.T) {
 	attrs := []label.KeyValue{label.Int("one", 1), label.Int("two", 2)}
 
-	got := Resource(resource.New(attrs...)).GetAttributes()
+	got := Resource(resource.NewWithAttributes(attrs...)).GetAttributes()
 	if !assert.Len(t, attrs, 2) {
 		return
 	}

exporters/otlp/internal/transform/span_test.go

@@ -252,7 +252,7 @@ func TestSpanData(t *testing.T) {
 		DroppedAttributeCount:    1,
 		DroppedMessageEventCount: 2,
 		DroppedLinkCount:         3,
-		Resource:                 resource.New(label.String("rk1", "rv1"), label.Int64("rk2", 5)),
+		Resource:                 resource.NewWithAttributes(label.String("rk1", "rv1"), label.Int64("rk2", 5)),
 		InstrumentationLibrary: instrumentation.Library{
 			Name:    "go.opentelemetry.io/test/otel",
 			Version: "v0.0.1",

exporters/otlp/otlp_integration_test.go

@@ -94,13 +94,13 @@ func newExporterEndToEndTest(t *testing.T, additionalOpts []otlp.ExporterOption)
 		),
 	}
 	tp1 := sdktrace.NewTracerProvider(append(pOpts,
-		sdktrace.WithResource(resource.New(
+		sdktrace.WithResource(resource.NewWithAttributes(
 			label.String("rk1", "rv11)"),
 			label.Int64("rk2", 5),
 		)))...)
 
 	tp2 := sdktrace.NewTracerProvider(append(pOpts,
-		sdktrace.WithResource(resource.New(
+		sdktrace.WithResource(resource.NewWithAttributes(
 			label.String("rk1", "rv12)"),
 			label.Float32("rk3", 6.5),
 		)))...)

exporters/otlp/otlp_metric_test.go

@@ -104,8 +104,8 @@ var (
 	baseKeyValues = []label.KeyValue{label.String("host", "test.com")}
 	cpuKey        = label.Key("CPU")
 
-	testInstA = resource.New(label.String("instance", "tester-a"))
+	testInstA = resource.NewWithAttributes(label.String("instance", "tester-a"))
-	testInstB = resource.New(label.String("instance", "tester-b"))
+	testInstB = resource.NewWithAttributes(label.String("instance", "tester-b"))
 
 	testHistogramBoundaries = []float64{2.0, 4.0, 8.0}
 

exporters/otlp/otlp_span_test.go

@@ -97,7 +97,7 @@ func TestExportSpans(t *testing.T) {
 					},
 					StatusCode:    codes.Ok,
 					StatusMessage: "Ok",
-					Resource:      resource.New(label.String("instance", "tester-a")),
+					Resource:      resource.NewWithAttributes(label.String("instance", "tester-a")),
 					InstrumentationLibrary: instrumentation.Library{
 						Name:    "lib-a",
 						Version: "v0.1.0",
@@ -119,7 +119,7 @@ func TestExportSpans(t *testing.T) {
 					},
 					StatusCode:    codes.Ok,
 					StatusMessage: "Ok",
-					Resource:      resource.New(label.String("instance", "tester-a")),
+					Resource:      resource.NewWithAttributes(label.String("instance", "tester-a")),
 					InstrumentationLibrary: instrumentation.Library{
 						Name:    "lib-b",
 						Version: "v0.1.0",
@@ -142,7 +142,7 @@ func TestExportSpans(t *testing.T) {
 					},
 					StatusCode:    codes.Ok,
 					StatusMessage: "Ok",
-					Resource:      resource.New(label.String("instance", "tester-a")),
+					Resource:      resource.NewWithAttributes(label.String("instance", "tester-a")),
 					InstrumentationLibrary: instrumentation.Library{
 						Name:    "lib-a",
 						Version: "v0.1.0",
@@ -164,7 +164,7 @@ func TestExportSpans(t *testing.T) {
 					},
 					StatusCode:    codes.Error,
 					StatusMessage: "Unauthenticated",
-					Resource:      resource.New(label.String("instance", "tester-b")),
+					Resource:      resource.NewWithAttributes(label.String("instance", "tester-b")),
 					InstrumentationLibrary: instrumentation.Library{
 						Name:    "lib-a",
 						Version: "v1.1.0",

exporters/stdout/metric_test.go

@@ -48,7 +48,7 @@ type testFixture struct {
 	output   *bytes.Buffer
 }
 
-var testResource = resource.New(label.String("R", "V"))
+var testResource = resource.NewWithAttributes(label.String("R", "V"))
 
 func newFixture(t *testing.T, opts ...stdout.Option) testFixture {
 	buf := &bytes.Buffer{}
@@ -290,11 +290,11 @@ func TestStdoutResource(t *testing.T) {
 	}
 	testCases := []testCase{
 		newCase("R1=V1,R2=V2,A=B,C=D",
-			resource.New(label.String("R1", "V1"), label.String("R2", "V2")),
+			resource.NewWithAttributes(label.String("R1", "V1"), label.String("R2", "V2")),
 			label.String("A", "B"),
 			label.String("C", "D")),
 		newCase("R1=V1,R2=V2",
-			resource.New(label.String("R1", "V1"), label.String("R2", "V2")),
+			resource.NewWithAttributes(label.String("R1", "V1"), label.String("R2", "V2")),
 		),
 		newCase("A=B,C=D",
 			nil,
@@ -304,7 +304,7 @@ func TestStdoutResource(t *testing.T) {
 		// We explicitly do not de-duplicate between resources
 		// and metric labels in this exporter.
 		newCase("R1=V1,R2=V2,R1=V3,R2=V4",
-			resource.New(label.String("R1", "V1"), label.String("R2", "V2")),
+			resource.NewWithAttributes(label.String("R1", "V1"), label.String("R2", "V2")),
 			label.String("R1", "V3"),
 			label.String("R2", "V4")),
 	}

exporters/stdout/trace_test.go

@@ -44,7 +44,7 @@ func TestExporter_ExportSpan(t *testing.T) {
 	spanID, _ := otel.SpanIDFromHex("0102030405060708")
 	keyValue := "value"
 	doubleValue := 123.456
-	resource := resource.New(label.String("rk1", "rv11"))
+	resource := resource.NewWithAttributes(label.String("rk1", "rv11"))
 
 	testSpan := &export.SpanData{
 		SpanContext: otel.SpanContext{

exporters/trace/jaeger/jaeger_test.go

@@ -409,7 +409,7 @@ func Test_spanDataToThrift(t *testing.T) {
 				StatusCode:    codes.Error,
 				StatusMessage: statusMessage,
 				SpanKind:      otel.SpanKindClient,
-				Resource:      resource.New(label.String("rk1", rv1), label.Int64("rk2", rv2)),
+				Resource:      resource.NewWithAttributes(label.String("rk1", rv1), label.Int64("rk2", rv2)),
 				InstrumentationLibrary: instrumentation.Library{
 					Name:    instrLibName,
 					Version: instrLibVersion,

sdk/metric/benchmark_test.go

@@ -42,7 +42,7 @@ func newFixture(b *testing.B) *benchFixture {
 		AggregatorSelector: processortest.AggregatorSelector(),
 	}
 
-	bf.accumulator = sdk.NewAccumulator(bf)
+	bf.accumulator = sdk.NewAccumulator(bf, nil)
 	bf.meter = otel.WrapMeterImpl(bf.accumulator, "benchmarks")
 	return bf
 }

sdk/metric/config.go

@@ -1,45 +0,0 @@
-// Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package metric
-
-import (
-	"go.opentelemetry.io/otel/sdk/resource"
-)
-
-// Config contains configuration for an SDK.
-type Config struct {
-	// Resource describes all the metric records processed by the
-	// Accumulator.
-	Resource *resource.Resource
-}
-
-// Option is the interface that applies the value to a configuration option.
-type Option interface {
-	// Apply sets the Option value of a Config.
-	Apply(*Config)
-}
-
-// WithResource sets the Resource configuration option of a Config.
-func WithResource(res *resource.Resource) Option {
-	return resourceOption{res}
-}
-
-type resourceOption struct {
-	*resource.Resource
-}
-
-func (o resourceOption) Apply(config *Config) {
-	config.Resource = o.Resource
-}

sdk/metric/controller/pull/pull.go

@@ -60,7 +60,7 @@ func New(checkpointer export.Checkpointer, options ...Option) *Controller {
 	}
 	accum := sdk.NewAccumulator(
 		checkpointer,
-		sdk.WithResource(config.Resource),
+		config.Resource,
 	)
 	return &Controller{
 		accumulator:  accum,

sdk/metric/controller/push/config_test.go

@@ -24,7 +24,7 @@ import (
 )
 
 func TestWithResource(t *testing.T) {
-	r := resource.New(label.String("A", "a"))
+	r := resource.NewWithAttributes(label.String("A", "a"))
 
 	c := &Config{}
 	WithResource(r).Apply(c)

sdk/metric/controller/push/push.go

@@ -61,7 +61,7 @@ func New(checkpointer export.Checkpointer, exporter export.Exporter, opts ...Opt
 
 	impl := sdk.NewAccumulator(
 		checkpointer,
-		sdk.WithResource(c.Resource),
+		c.Resource,
 	)
 	return &Controller{
 		provider:     registry.NewMeterProvider(impl),

sdk/metric/controller/push/push_test.go

@@ -36,7 +36,7 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 
-var testResource = resource.New(label.String("R", "V"))
+var testResource = resource.NewWithAttributes(label.String("R", "V"))
 
 type handler struct {
 	sync.Mutex

sdk/metric/correct_test.go

@@ -34,7 +34,7 @@ import (
 )
 
 var Must = otel.Must
-var testResource = resource.New(label.String("R", "V"))
+var testResource = resource.NewWithAttributes(label.String("R", "V"))
 
 type handler struct {
 	sync.Mutex
@@ -96,7 +96,7 @@ func newSDK(t *testing.T) (otel.Meter, *metricsdk.Accumulator, *correctnessProce
 	}
 	accum := metricsdk.NewAccumulator(
 		processor,
-		metricsdk.WithResource(testResource),
+		testResource,
 	)
 	meter := otel.WrapMeterImpl(accum, "test")
 	return meter, accum, processor

sdk/metric/processor/basic/basic_test.go

@@ -121,7 +121,7 @@ func testProcessor(
 	// Note: this selector uses the instrument name to dictate
 	// aggregation kind.
 	selector := processorTest.AggregatorSelector()
-	res := resource.New(label.String("R", "V"))
+	res := resource.NewWithAttributes(label.String("R", "V"))
 
 	labs1 := []label.KeyValue{label.String("L1", "V")}
 	labs2 := []label.KeyValue{label.String("L2", "V")}
@@ -361,7 +361,7 @@ func TestBasicTimestamps(t *testing.T) {
 }
 
 func TestStatefulNoMemoryCumulative(t *testing.T) {
-	res := resource.New(label.String("R", "V"))
+	res := resource.NewWithAttributes(label.String("R", "V"))
 	ekind := export.CumulativeExporter
 
 	desc := otel.NewDescriptor("inst.sum", otel.CounterInstrumentKind, otel.Int64NumberKind)
@@ -395,7 +395,7 @@ func TestStatefulNoMemoryCumulative(t *testing.T) {
 }
 
 func TestStatefulNoMemoryDelta(t *testing.T) {
-	res := resource.New(label.String("R", "V"))
+	res := resource.NewWithAttributes(label.String("R", "V"))
 	ekind := export.DeltaExporter
 
 	desc := otel.NewDescriptor("inst.sum", otel.SumObserverInstrumentKind, otel.Int64NumberKind)
@@ -435,7 +435,7 @@ func TestMultiObserverSum(t *testing.T) {
 		export.DeltaExporter,
 	} {
 
-		res := resource.New(label.String("R", "V"))
+		res := resource.NewWithAttributes(label.String("R", "V"))
 		desc := otel.NewDescriptor("observe.sum", otel.SumObserverInstrumentKind, otel.Int64NumberKind)
 		selector := processorTest.AggregatorSelector()
 

sdk/metric/processor/processortest/test_test.go

@@ -32,9 +32,7 @@ func generateTestData(proc export.Processor) {
 	ctx := context.Background()
 	accum := metricsdk.NewAccumulator(
 		proc,
-		metricsdk.WithResource(
+		resource.NewWithAttributes(label.String("R", "V")),
-			resource.New(label.String("R", "V")),
-		),
 	)
 	meter := otel.WrapMeterImpl(accum, "testing")
 

sdk/metric/processor/reducer/reducer_test.go

@@ -75,9 +75,7 @@ func TestFilterProcessor(t *testing.T) {
 	)
 	accum := metricsdk.NewAccumulator(
 		reducer.New(testFilter{}, processorTest.Checkpointer(testProc)),
-		metricsdk.WithResource(
+		resource.NewWithAttributes(label.String("R", "V")),
-			resource.New(label.String("R", "V")),
-		),
 	)
 	generateData(accum)
 
@@ -94,9 +92,7 @@ func TestFilterBasicProcessor(t *testing.T) {
 	basicProc := basic.New(processorTest.AggregatorSelector(), export.CumulativeExporter)
 	accum := metricsdk.NewAccumulator(
 		reducer.New(testFilter{}, basicProc),
-		metricsdk.WithResource(
+		resource.NewWithAttributes(label.String("R", "V")),
-			resource.New(label.String("R", "V")),
-		),
 	)
 	exporter := processorTest.NewExporter(basicProc, label.DefaultEncoder())
 

sdk/metric/sdk.go

@@ -305,16 +305,11 @@ func (s *syncInstrument) RecordOne(ctx context.Context, number api.Number, kvs [
 // processor will call Collect() when it receives a request to scrape
 // current metric values.  A push-based processor should configure its
 // own periodic collection.
-func NewAccumulator(processor export.Processor, opts ...Option) *Accumulator {
+func NewAccumulator(processor export.Processor, resource *resource.Resource) *Accumulator {
-	c := &Config{}
-	for _, opt := range opts {
-		opt.Apply(c)
-	}
-
 	return &Accumulator{
 		processor:        processor,
 		asyncInstruments: internal.NewAsyncInstrumentState(),
-		resource:         c.Resource,
+		resource:         resource,
 	}
 }
 

sdk/metric/stress_test.go

@@ -292,7 +292,8 @@ func stressTest(t *testing.T, impl testImpl) {
 		AggregatorSelector: processortest.AggregatorSelector(),
 	}
 	cc := concurrency()
-	sdk := NewAccumulator(fixture)
+
+	sdk := NewAccumulator(fixture, nil)
 	meter := otel.WrapMeterImpl(sdk, "stress_test")
 	fixture.wg.Add(cc + 1)
 

sdk/resource/auto.go

@@ -43,6 +43,9 @@ func Detect(ctx context.Context, detectors ...Detector) (*Resource, error) {
 	var autoDetectedRes *Resource
 	var errInfo []string
 	for _, detector := range detectors {
+		if detector == nil {
+			continue
+		}
 		res, err := detector.Detect(ctx)
 		if err != nil {
 			errInfo = append(errInfo, err.Error())

sdk/resource/benchmark_test.go

@@ -47,7 +47,7 @@ func makeLabels(n int) (_, _ *resource.Resource) {
 		}
 
 	}
-	return resource.New(l1...), resource.New(l2...)
+	return resource.NewWithAttributes(l1...), resource.NewWithAttributes(l2...)
 }
 
 func benchmarkMergeResource(b *testing.B, size int) {

sdk/resource/builtin.go

@@ -0,0 +1,81 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"go.opentelemetry.io/otel/label"
+	opentelemetry "go.opentelemetry.io/otel/sdk"
+	"go.opentelemetry.io/otel/semconv"
+)
+
+type (
+	// TelemetrySDK is a Detector that provides information about
+	// the OpenTelemetry SDK used.  This Detector is included as a
+	// builtin. If these resource attributes are not wanted, use
+	// the WithTelemetrySDK(nil) or WithoutBuiltin() options to
+	// explicitly disable them.
+	TelemetrySDK struct{}
+
+	// Host is a Detector that provides information about the host
+	// being run on. This Detector is included as a builtin. If
+	// these resource attributes are not wanted, use the
+	// WithHost(nil) or WithoutBuiltin() options to explicitly
+	// disable them.
+	Host struct{}
+
+	stringDetector struct {
+		K label.Key
+		F func() (string, error)
+	}
+)
+
+var (
+	_ Detector = TelemetrySDK{}
+	_ Detector = Host{}
+	_ Detector = stringDetector{}
+)
+
+// Detect returns a *Resource that describes the OpenTelemetry SDK used.
+func (TelemetrySDK) Detect(context.Context) (*Resource, error) {
+	return NewWithAttributes(
+		semconv.TelemetrySDKNameKey.String("opentelemetry-go"),
+		semconv.TelemetrySDKLanguageKey.String("go"),
+		semconv.TelemetrySDKVersionKey.String(opentelemetry.Version()),
+	), nil
+}
+
+// Detect returns a *Resource that describes the host being run on.
+func (Host) Detect(ctx context.Context) (*Resource, error) {
+	return StringDetector(semconv.HostNameKey, os.Hostname).Detect(ctx)
+}
+
+// StringDetector returns a Detector that will produce a *Resource
+// containing the string as a value corresponding to k.
+func StringDetector(k label.Key, f func() (string, error)) Detector {
+	return stringDetector{K: k, F: f}
+}
+
+// Detect implements Detector.
+func (sd stringDetector) Detect(ctx context.Context) (*Resource, error) {
+	value, err := sd.F()
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", string(sd.K), err)
+	}
+	return NewWithAttributes(sd.K.String(value)), nil
+}

sdk/resource/builtin_test.go

@@ -0,0 +1,59 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource_test
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+func TestBuiltinStringDetector(t *testing.T) {
+	E := fmt.Errorf("no K")
+	res, err := resource.StringDetector(label.Key("K"), func() (string, error) {
+		return "", E
+	}).Detect(context.Background())
+	require.True(t, errors.Is(err, E))
+	require.NotEqual(t, E, err)
+	require.Nil(t, res)
+}
+
+func TestBuiltinStringConfig(t *testing.T) {
+	res, err := resource.New(
+		context.Background(),
+		resource.WithoutBuiltin(),
+		resource.WithAttributes(label.String("A", "B")),
+		resource.WithDetectors(resource.StringDetector(label.Key("K"), func() (string, error) {
+			return "", fmt.Errorf("K-IS-MISSING")
+		})),
+	)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "K-IS-MISSING")
+	require.NotNil(t, res)
+
+	m := map[string]string{}
+	for _, kv := range res.Attributes() {
+		m[string(kv.Key)] = kv.Value.Emit()
+	}
+	require.EqualValues(t, map[string]string{
+		"A": "B",
+	}, m)
+}

sdk/resource/config.go

@@ -0,0 +1,150 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/label"
+)
+
+// config contains configuration for Resource creation.
+type config struct {
+	// detectors that will be evaluated.
+	detectors []Detector
+
+	// telemetrySDK is used to specify non-default
+	// `telemetry.sdk.*` attributes.
+	telemetrySDK Detector
+
+	// HostResource is used to specify non-default `host.*`
+	// attributes.
+	host Detector
+
+	// FromEnv is used to specify non-default OTEL_RESOURCE_ATTRIBUTES
+	// attributes.
+	fromEnv Detector
+}
+
+// Option is the interface that applies a configuration option.
+type Option interface {
+	// Apply sets the Option value of a config.
+	Apply(*config)
+}
+
+// WithAttributes adds attributes to the configured Resource.
+func WithAttributes(attributes ...label.KeyValue) Option {
+	return WithDetectors(detectAttributes{attributes})
+}
+
+type detectAttributes struct {
+	attributes []label.KeyValue
+}
+
+func (d detectAttributes) Detect(context.Context) (*Resource, error) {
+	return NewWithAttributes(d.attributes...), nil
+}
+
+// WithDetectors adds detectors to be evaluated for the configured resource.
+func WithDetectors(detectors ...Detector) Option {
+	return detectorsOption{detectors}
+}
+
+type detectorsOption struct {
+	detectors []Detector
+}
+
+// Apply implements Option.
+func (o detectorsOption) Apply(cfg *config) {
+	cfg.detectors = append(cfg.detectors, o.detectors...)
+}
+
+// WithTelemetrySDK overrides the builtin `telemetry.sdk.*`
+// attributes.  Use nil to disable these attributes entirely.
+func WithTelemetrySDK(d Detector) Option {
+	return telemetrySDKOption{d}
+}
+
+type telemetrySDKOption struct {
+	Detector
+}
+
+// Apply implements Option.
+func (o telemetrySDKOption) Apply(cfg *config) {
+	cfg.telemetrySDK = o.Detector
+}
+
+// WithHost overrides the builtin `host.*` attributes.  Use nil to
+// disable these attributes entirely.
+func WithHost(d Detector) Option {
+	return hostOption{d}
+}
+
+type hostOption struct {
+	Detector
+}
+
+// Apply implements Option.
+func (o hostOption) Apply(cfg *config) {
+	cfg.host = o.Detector
+}
+
+// WithFromEnv overrides the builtin detector for
+// OTEL_RESOURCE_ATTRIBUTES.  Use nil to disable environment checking.
+func WithFromEnv(d Detector) Option {
+	return fromEnvOption{d}
+}
+
+type fromEnvOption struct {
+	Detector
+}
+
+// Apply implements Option.
+func (o fromEnvOption) Apply(cfg *config) {
+	cfg.fromEnv = o.Detector
+}
+
+// WithoutBuiltin disables all the builtin detectors, including the
+// telemetry.sdk.*, host.*, and the environment detector.
+func WithoutBuiltin() Option {
+	return noBuiltinOption{}
+}
+
+type noBuiltinOption struct{}
+
+// Apply implements Option.
+func (o noBuiltinOption) Apply(cfg *config) {
+	cfg.host = nil
+	cfg.telemetrySDK = nil
+	cfg.fromEnv = nil
+}
+
+// New returns a Resource combined from the provided attributes,
+// user-provided detectors and builtin detectors.
+func New(ctx context.Context, opts ...Option) (*Resource, error) {
+	cfg := config{
+		telemetrySDK: TelemetrySDK{},
+		host:         Host{},
+		fromEnv:      FromEnv{},
+	}
+	for _, opt := range opts {
+		opt.Apply(&cfg)
+	}
+	detectors := append(
+		[]Detector{cfg.telemetrySDK, cfg.host, cfg.fromEnv},
+		cfg.detectors...,
+	)
+	return Detect(ctx, detectors...)
+}

sdk/resource/config_test.go

@@ -0,0 +1,139 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource_test
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	ottest "go.opentelemetry.io/otel/internal/testing"
+	"go.opentelemetry.io/otel/label"
+	opentelemetry "go.opentelemetry.io/otel/sdk"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+const envVar = "OTEL_RESOURCE_ATTRIBUTES"
+
+func TestDefaultConfig(t *testing.T) {
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
+
+	ctx := context.Background()
+	res, err := resource.New(ctx)
+	require.NoError(t, err)
+	require.EqualValues(t, map[string]string{
+		"host.name":              hostname(),
+		"telemetry.sdk.name":     "opentelemetry-go",
+		"telemetry.sdk.language": "go",
+		"telemetry.sdk.version":  opentelemetry.Version(),
+	}, toMap(res))
+}
+
+func TestDefaultConfigNoHost(t *testing.T) {
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
+
+	ctx := context.Background()
+	res, err := resource.New(ctx, resource.WithHost(nil))
+	require.NoError(t, err)
+	require.EqualValues(t, map[string]string{
+		"telemetry.sdk.name":     "opentelemetry-go",
+		"telemetry.sdk.language": "go",
+		"telemetry.sdk.version":  opentelemetry.Version(),
+	}, toMap(res))
+}
+
+func TestDefaultConfigNoEnv(t *testing.T) {
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "from=here",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
+
+	ctx := context.Background()
+	res, err := resource.New(ctx, resource.WithFromEnv(nil))
+	require.NoError(t, err)
+	require.EqualValues(t, map[string]string{
+		"host.name":              hostname(),
+		"telemetry.sdk.name":     "opentelemetry-go",
+		"telemetry.sdk.language": "go",
+		"telemetry.sdk.version":  opentelemetry.Version(),
+	}, toMap(res))
+}
+
+func TestDefaultConfigWithEnv(t *testing.T) {
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "key=value,other=attr",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
+
+	ctx := context.Background()
+	res, err := resource.New(ctx)
+	require.NoError(t, err)
+	require.EqualValues(t, map[string]string{
+		"key":                    "value",
+		"other":                  "attr",
+		"host.name":              hostname(),
+		"telemetry.sdk.name":     "opentelemetry-go",
+		"telemetry.sdk.language": "go",
+		"telemetry.sdk.version":  opentelemetry.Version(),
+	}, toMap(res))
+}
+
+func TestWithoutBuiltin(t *testing.T) {
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "key=value,other=attr",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
+
+	ctx := context.Background()
+	res, err := resource.New(
+		ctx,
+		resource.WithoutBuiltin(),
+		resource.WithAttributes(label.String("hello", "collector")),
+	)
+	require.NoError(t, err)
+	require.EqualValues(t, map[string]string{
+		"hello": "collector",
+	}, toMap(res))
+}
+
+func toMap(res *resource.Resource) map[string]string {
+	m := map[string]string{}
+	for _, attr := range res.Attributes() {
+		m[string(attr.Key)] = attr.Value.Emit()
+	}
+	return m
+}
+
+func hostname() string {
+	hn, err := os.Hostname()
+	if err != nil {
+		return fmt.Sprintf("hostname(%s)", err)
+	}
+	return hn
+}

sdk/resource/env.go

@@ -27,19 +27,22 @@ import (
 const envVar = "OTEL_RESOURCE_ATTRIBUTES"
 
 var (
-	//errMissingValue is returned when a resource value is missing.
+	// errMissingValue is returned when a resource value is missing.
 	errMissingValue = fmt.Errorf("%w: missing value", ErrPartialResource)
 )
 
-// FromEnv is a detector that implements the Detector and collects resources
+// FromEnv is a Detector that implements the Detector and collects
-// from environment
+// resources from environment.  This Detector is included as a
+// builtin.  If these resource attributes are not wanted, use the
+// WithFromEnv(nil) or WithoutBuiltin() options to explicitly disable
+// them.
 type FromEnv struct{}
 
 // compile time assertion that FromEnv implements Detector interface
-var _ Detector = (*FromEnv)(nil)
+var _ Detector = FromEnv{}
 
 // Detect collects resources from environment
-func (d *FromEnv) Detect(context.Context) (*Resource, error) {
+func (FromEnv) Detect(context.Context) (*Resource, error) {
 	labels := strings.TrimSpace(os.Getenv(envVar))
 
 	if labels == "" {
@@ -65,5 +68,5 @@ func constructOTResources(s string) (*Resource, error) {
 	if len(invalid) > 0 {
 		err = fmt.Errorf("%w: %v", errMissingValue, invalid)
 	}
-	return New(labels...), err
+	return NewWithAttributes(labels...), err
 }

sdk/resource/env_test.go

@@ -17,32 +17,40 @@ package resource
 import (
 	"context"
 	"fmt"
-	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	ottest "go.opentelemetry.io/otel/internal/testing"
 	"go.opentelemetry.io/otel/label"
 )
 
 func TestDetectOnePair(t *testing.T) {
-	os.Setenv(envVar, "key=value")
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "key=value",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
 
 	detector := &FromEnv{}
 	res, err := detector.Detect(context.Background())
 	require.NoError(t, err)
-	assert.Equal(t, New(label.String("key", "value")), res)
+	assert.Equal(t, NewWithAttributes(label.String("key", "value")), res)
 }
 
 func TestDetectMultiPairs(t *testing.T) {
-	os.Setenv("x", "1")
+	store, err := ottest.SetEnvVariables(map[string]string{
-	os.Setenv(envVar, "key=value, k = v , a= x, a=z")
+		"x":    "1",
+		envVar: "key=value, k = v , a= x, a=z",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
 
 	detector := &FromEnv{}
 	res, err := detector.Detect(context.Background())
 	require.NoError(t, err)
-	assert.Equal(t, res, New(
+	assert.Equal(t, res, NewWithAttributes(
 		label.String("key", "value"),
 		label.String("k", "v"),
 		label.String("a", "x"),
@@ -51,7 +59,11 @@ func TestDetectMultiPairs(t *testing.T) {
 }
 
 func TestEmpty(t *testing.T) {
-	os.Setenv(envVar, "   ")
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "   ",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
 
 	detector := &FromEnv{}
 	res, err := detector.Detect(context.Background())
@@ -60,13 +72,17 @@ func TestEmpty(t *testing.T) {
 }
 
 func TestMissingKeyError(t *testing.T) {
-	os.Setenv(envVar, "key=value,key")
+	store, err := ottest.SetEnvVariables(map[string]string{
+		envVar: "key=value,key",
+	})
+	require.NoError(t, err)
+	defer func() { require.NoError(t, store.Restore()) }()
 
 	detector := &FromEnv{}
 	res, err := detector.Detect(context.Background())
 	assert.Error(t, err)
 	assert.Equal(t, err, fmt.Errorf("%w: %v", errMissingValue, "[key]"))
-	assert.Equal(t, res, New(
+	assert.Equal(t, res, NewWithAttributes(
 		label.String("key", "value"),
 	))
 }

sdk/resource/resource.go

@@ -31,10 +31,10 @@ type Resource struct {
 
 var emptyResource Resource
 
-// New creates a resource from a set of attributes.  If there are
+// NewWithAttributes creates a resource from a set of attributes.  If there are
 // duplicate keys present in the list of attributes, then the last
 // value found for the key is preserved.
-func New(kvs ...label.KeyValue) *Resource {
+func NewWithAttributes(kvs ...label.KeyValue) *Resource {
 	return &Resource{
 		labels: label.NewSet(kvs...),
 	}
@@ -103,7 +103,7 @@ func Merge(a, b *Resource) *Resource {
 	for mi.Next() {
 		combine = append(combine, mi.Label())
 	}
-	return New(combine...)
+	return NewWithAttributes(combine...)
 }
 
 // Empty returns an instance of Resource with no attributes.  It is

sdk/resource/resource_test.go

@@ -58,7 +58,7 @@ func TestNew(t *testing.T) {
 	}
 	for _, c := range cases {
 		t.Run(fmt.Sprintf("case-%s", c.name), func(t *testing.T) {
-			res := resource.New(c.in...)
+			res := resource.NewWithAttributes(c.in...)
 			if diff := cmp.Diff(
 				res.Attributes(),
 				c.want,
@@ -77,61 +77,61 @@ func TestMerge(t *testing.T) {
 	}{
 		{
 			name: "Merge with no overlap, no nil",
-			a:    resource.New(kv11, kv31),
+			a:    resource.NewWithAttributes(kv11, kv31),
-			b:    resource.New(kv21, kv41),
+			b:    resource.NewWithAttributes(kv21, kv41),
 			want: []label.KeyValue{kv11, kv21, kv31, kv41},
 		},
 		{
 			name: "Merge with no overlap, no nil, not interleaved",
-			a:    resource.New(kv11, kv21),
+			a:    resource.NewWithAttributes(kv11, kv21),
-			b:    resource.New(kv31, kv41),
+			b:    resource.NewWithAttributes(kv31, kv41),
 			want: []label.KeyValue{kv11, kv21, kv31, kv41},
 		},
 		{
 			name: "Merge with common key order1",
-			a:    resource.New(kv11),
+			a:    resource.NewWithAttributes(kv11),
-			b:    resource.New(kv12, kv21),
+			b:    resource.NewWithAttributes(kv12, kv21),
 			want: []label.KeyValue{kv11, kv21},
 		},
 		{
 			name: "Merge with common key order2",
-			a:    resource.New(kv12, kv21),
+			a:    resource.NewWithAttributes(kv12, kv21),
-			b:    resource.New(kv11),
+			b:    resource.NewWithAttributes(kv11),
 			want: []label.KeyValue{kv12, kv21},
 		},
 		{
 			name: "Merge with common key order4",
-			a:    resource.New(kv11, kv21, kv41),
+			a:    resource.NewWithAttributes(kv11, kv21, kv41),
-			b:    resource.New(kv31, kv41),
+			b:    resource.NewWithAttributes(kv31, kv41),
 			want: []label.KeyValue{kv11, kv21, kv31, kv41},
 		},
 		{
 			name: "Merge with no keys",
-			a:    resource.New(),
+			a:    resource.NewWithAttributes(),
-			b:    resource.New(),
+			b:    resource.NewWithAttributes(),
 			want: nil,
 		},
 		{
 			name: "Merge with first resource no keys",
-			a:    resource.New(),
+			a:    resource.NewWithAttributes(),
-			b:    resource.New(kv21),
+			b:    resource.NewWithAttributes(kv21),
 			want: []label.KeyValue{kv21},
 		},
 		{
 			name: "Merge with second resource no keys",
-			a:    resource.New(kv11),
+			a:    resource.NewWithAttributes(kv11),
-			b:    resource.New(),
+			b:    resource.NewWithAttributes(),
 			want: []label.KeyValue{kv11},
 		},
 		{
 			name: "Merge with first resource nil",
 			a:    nil,
-			b:    resource.New(kv21),
+			b:    resource.NewWithAttributes(kv21),
 			want: []label.KeyValue{kv21},
 		},
 		{
 			name: "Merge with second resource nil",
-			a:    resource.New(kv11),
+			a:    resource.NewWithAttributes(kv11),
 			b:    nil,
 			want: []label.KeyValue{kv11},
 		},
@@ -207,14 +207,14 @@ func TestString(t *testing.T) {
 			want: `A\=a\\\,B=b`,
 		},
 	} {
-		if got := resource.New(test.kvs...).String(); got != test.want {
+		if got := resource.NewWithAttributes(test.kvs...).String(); got != test.want {
 			t.Errorf("Resource(%v).String() = %q, want %q", test.kvs, got, test.want)
 		}
 	}
 }
 
 func TestMarshalJSON(t *testing.T) {
-	r := resource.New(label.Int64("A", 1), label.String("C", "D"))
+	r := resource.NewWithAttributes(label.Int64("A", 1), label.String("C", "D"))
 	data, err := json.Marshal(r)
 	require.NoError(t, err)
 	require.Equal(t,

sdk/trace/trace_test.go

@@ -1169,7 +1169,7 @@ func TestWithResource(t *testing.T) {
 	te := NewTestExporter()
 	tp := NewTracerProvider(WithSyncer(te),
 		WithConfig(Config{DefaultSampler: AlwaysSample()}),
-		WithResource(resource.New(label.String("rk1", "rv1"), label.Int64("rk2", 5))))
+		WithResource(resource.NewWithAttributes(label.String("rk1", "rv1"), label.Int64("rk2", 5))))
 	span := startSpan(tp, "WithResource")
 	span.SetAttributes(label.String("key1", "value1"))
 	got, err := endSpan(te, span)
@@ -1189,7 +1189,7 @@ func TestWithResource(t *testing.T) {
 		},
 		SpanKind:               otel.SpanKindInternal,
 		HasRemoteParent:        true,
-		Resource:               resource.New(label.String("rk1", "rv1"), label.Int64("rk2", 5)),
+		Resource:               resource.NewWithAttributes(label.String("rk1", "rv1"), label.Int64("rk2", 5)),
 		InstrumentationLibrary: instrumentation.Library{Name: "WithResource"},
 	}
 	if diff := cmpDiff(got, want); diff != "" {