Pass Resources through the metrics export pipeline (#659)

api/metric/api.go

@@ -21,7 +21,6 @@ import (
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/unit"
-	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // Provider supports named Meter instances.
@@ -38,8 +37,6 @@ type Config struct {
 	Description string
 	// Unit is an optional field describing the metric instrument.
 	Unit unit.Unit
-	// Resource describes the entity for which measurements are made.
-	Resource *resource.Resource
 	// LibraryName is the name given to the Meter that created
 	// this instrument.  See `Provider`.
 	LibraryName string
@@ -132,12 +129,6 @@ func (d Descriptor) NumberKind() core.NumberKind {
 	return d.numberKind
 }
 
-// Resource returns the Resource describing the entity for which the metric
-// instrument measures.
-func (d Descriptor) Resource() *resource.Resource {
-	return d.config.Resource
-}
-
 // LibraryName returns the metric instrument's library name, typically
 // given via a call to Provider.Meter().
 func (d Descriptor) LibraryName() string {
@@ -200,19 +191,6 @@ func (u unitOption) Apply(config *Config) {
 	config.Unit = unit.Unit(u)
 }
 
-// WithResource applies provided Resource.
-//
-// This will override any existing Resource.
-func WithResource(r *resource.Resource) Option {
-	return resourceOption{r}
-}
-
-type resourceOption struct{ *resource.Resource }
-
-func (r resourceOption) Apply(config *Config) {
-	config.Resource = r.Resource
-}
-
 // WithLibraryName applies provided library name.  This is meant for
 // use in `Provider` implementations that have not used
 // `WrapMeterImpl`.  Implementations built using `WrapMeterImpl` have

api/metric/api_test.go

@@ -25,7 +25,6 @@ import (
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/api/unit"
 	mockTest "go.opentelemetry.io/otel/internal/metric"
-	"go.opentelemetry.io/otel/sdk/resource"
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/stretchr/testify/assert"
@@ -36,28 +35,25 @@ var Must = metric.Must
 
 func TestOptions(t *testing.T) {
 	type testcase struct {
-		name     string
-		opts     []metric.Option
-		desc     string
-		unit     unit.Unit
-		resource *resource.Resource
+		name string
+		opts []metric.Option
+		desc string
+		unit unit.Unit
 	}
 	testcases := []testcase{
 		{
-			name:     "no opts",
-			opts:     nil,
-			desc:     "",
-			unit:     "",
-			resource: nil,
+			name: "no opts",
+			opts: nil,
+			desc: "",
+			unit: "",
 		},
 		{
 			name: "description",
 			opts: []metric.Option{
 				metric.WithDescription("stuff"),
 			},
-			desc:     "stuff",
-			unit:     "",
-			resource: nil,
+			desc: "stuff",
+			unit: "",
 		},
 		{
 			name: "description override",
@@ -65,18 +61,16 @@ func TestOptions(t *testing.T) {
 				metric.WithDescription("stuff"),
 				metric.WithDescription("things"),
 			},
-			desc:     "things",
-			unit:     "",
-			resource: nil,
+			desc: "things",
+			unit: "",
 		},
 		{
 			name: "unit",
 			opts: []metric.Option{
 				metric.WithUnit("s"),
 			},
-			desc:     "",
-			unit:     "s",
-			resource: nil,
+			desc: "",
+			unit: "s",
 		},
 		{
 			name: "unit override",
@@ -84,18 +78,8 @@ func TestOptions(t *testing.T) {
 				metric.WithUnit("s"),
 				metric.WithUnit("h"),
 			},
-			desc:     "",
-			unit:     "h",
-			resource: nil,
-		},
-		{
-			name: "resource override",
-			opts: []metric.Option{
-				metric.WithResource(resource.New(key.New("name").String("test-name"))),
-			},
-			desc:     "",
-			unit:     "",
-			resource: resource.New(key.New("name").String("test-name")),
+			desc: "",
+			unit: "h",
 		},
 	}
 	for idx, tt := range testcases {
@@ -103,7 +87,6 @@ func TestOptions(t *testing.T) {
 		if diff := cmp.Diff(metric.Configure(tt.opts), metric.Config{
 			Description: tt.desc,
 			Unit:        tt.unit,
-			Resource:    tt.resource,
 		}); diff != "" {
 			t.Errorf("Compare options: -got +want %s", diff)
 		}

api/metric/sdkhelpers.go

@@ -18,7 +18,6 @@ import (
 	"context"
 
 	"go.opentelemetry.io/otel/api/core"
-	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // MeterImpl is a convenient interface for SDK and test
@@ -122,29 +121,6 @@ func Configure(opts []Option) Config {
 	return config
 }
 
-// Resourcer is implemented by any value that has a Resource method,
-// which returns the Resource associated with the value.
-// The Resource method is used to set the Resource for Descriptors of new
-// metric instruments.
-type Resourcer interface {
-	Resource() *resource.Resource
-}
-
-// insertResource inserts a WithResource option at the beginning of opts
-// using the resource defined by impl if impl implements Resourcer.
-//
-// If opts contains a WithResource option already, that Option will take
-// precedence and overwrite the Resource set from impl.
-//
-// The returned []Option may uses the same underlying array as opts.
-func insertResource(impl MeterImpl, opts []Option) []Option {
-	if r, ok := impl.(Resourcer); ok {
-		// default to the impl resource and override if passed in opts.
-		return append([]Option{WithResource(r.Resource())}, opts...)
-	}
-	return opts
-}
-
 // WrapMeterImpl constructs a `Meter` implementation from a
 // `MeterImpl` implementation.
 func WrapMeterImpl(impl MeterImpl, libraryName string) Meter {
@@ -159,7 +135,6 @@ func (m *wrappedMeterImpl) RecordBatch(ctx context.Context, ls []core.KeyValue,
 }
 
 func (m *wrappedMeterImpl) newSync(name string, metricKind Kind, numberKind core.NumberKind, opts []Option) (SyncImpl, error) {
-	opts = insertResource(m.impl, opts)
 	desc := NewDescriptor(name, metricKind, numberKind, opts...)
 	desc.config.LibraryName = m.libraryName
 	return m.impl.NewSyncInstrument(desc)
@@ -222,7 +197,6 @@ func WrapFloat64MeasureInstrument(syncInst SyncImpl, err error) (Float64Measure,
 }
 
 func (m *wrappedMeterImpl) newAsync(name string, mkind Kind, nkind core.NumberKind, opts []Option, callback func(func(core.Number, []core.KeyValue))) (AsyncImpl, error) {
-	opts = insertResource(m.impl, opts)
 	desc := NewDescriptor(name, mkind, nkind, opts...)
 	desc.config.LibraryName = m.libraryName
 	return m.impl.NewAsyncInstrument(desc, callback)

exporters/metric/prometheus/prometheus.go

@@ -31,6 +31,7 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/batcher/ungrouped"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
 	"go.opentelemetry.io/otel/sdk/metric/selector/simple"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // Exporter is an implementation of metric.Exporter that sends metrics to
@@ -167,7 +168,8 @@ func NewExportPipeline(config Config, period time.Duration) (*push.Controller, h
 }
 
 // Export exports the provide metric record to prometheus.
-func (e *Exporter) Export(_ context.Context, checkpointSet export.CheckpointSet) error {
+func (e *Exporter) Export(_ context.Context, _ *resource.Resource, checkpointSet export.CheckpointSet) error {
+	// TODO: Use the resource value in this exporter.
 	e.snapshot = checkpointSet
 	return nil
 }

exporters/metric/prometheus/prometheus_test.go

@@ -26,7 +26,6 @@ import (
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/key"
-	"go.opentelemetry.io/otel/api/label"
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/exporters/metric/prometheus"
 	"go.opentelemetry.io/otel/exporters/metric/test"
@@ -41,7 +40,7 @@ func TestPrometheusExporter(t *testing.T) {
 	}
 
 	var expected []string
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	counter := metric.NewDescriptor(
 		"counter", metric.CounterKind, core.Float64NumberKind)
@@ -119,7 +118,7 @@ func TestPrometheusExporter(t *testing.T) {
 }
 
 func compareExport(t *testing.T, exporter *prometheus.Exporter, checkpointSet *test.CheckpointSet, expected []string) {
-	err := exporter.Export(context.Background(), checkpointSet)
+	err := exporter.Export(context.Background(), nil, checkpointSet)
 	require.Nil(t, err)
 
 	rec := httptest.NewRecorder()

exporters/metric/stdout/stdout.go

@@ -25,6 +25,7 @@ import (
 
 	"go.opentelemetry.io/otel/api/global"
 	"go.opentelemetry.io/otel/api/label"
+	"go.opentelemetry.io/otel/sdk/resource"
 
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregator"
@@ -120,8 +121,8 @@ func NewRawExporter(config Config) (*Exporter, error) {
 // 	}
 // 	defer pipeline.Stop()
 // 	... Done
-func InstallNewPipeline(config Config) (*push.Controller, error) {
-	controller, err := NewExportPipeline(config, time.Minute)
+func InstallNewPipeline(config Config, opts ...push.Option) (*push.Controller, error) {
+	controller, err := NewExportPipeline(config, time.Minute, opts...)
 	if err != nil {
 		return controller, err
 	}
@@ -131,26 +132,27 @@ func InstallNewPipeline(config Config) (*push.Controller, error) {
 
 // NewExportPipeline sets up a complete export pipeline with the recommended setup,
 // chaining a NewRawExporter into the recommended selectors and batchers.
-func NewExportPipeline(config Config, period time.Duration) (*push.Controller, error) {
+func NewExportPipeline(config Config, period time.Duration, opts ...push.Option) (*push.Controller, error) {
 	selector := simple.NewWithExactMeasure()
 	exporter, err := NewRawExporter(config)
 	if err != nil {
 		return nil, err
 	}
 	batcher := ungrouped.New(selector, true)
-	pusher := push.New(batcher, exporter, period)
+	pusher := push.New(batcher, exporter, period, opts...)
 	pusher.Start()
 
 	return pusher, nil
 }
 
-func (e *Exporter) Export(_ context.Context, checkpointSet export.CheckpointSet) error {
+func (e *Exporter) Export(_ context.Context, resource *resource.Resource, checkpointSet export.CheckpointSet) error {
 	var aggError error
 	var batch expoBatch
 	if !e.config.DoNotPrintTime {
 		ts := time.Now()
 		batch.Timestamp = &ts
 	}
+	encodedResource := resource.Encoded(e.config.LabelEncoder)
 	aggError = checkpointSet.ForEach(func(record export.Record) error {
 		desc := record.Descriptor()
 		agg := record.Aggregator()
@@ -224,8 +226,12 @@ func (e *Exporter) Export(_ context.Context, checkpointSet export.CheckpointSet)
 
 		sb.WriteString(desc.Name())
 
-		if len(encodedLabels) > 0 {
+		if len(encodedLabels) > 0 || len(encodedResource) > 0 {
 			sb.WriteRune('{')
+			sb.WriteString(encodedResource)
+			if len(encodedLabels) > 0 && len(encodedResource) > 0 {
+				sb.WriteRune(',')
+			}
 			sb.WriteString(encodedLabels)
 			sb.WriteRune('}')
 		}

exporters/metric/stdout/stdout_test.go

@@ -26,7 +26,6 @@ import (
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/key"
-	"go.opentelemetry.io/otel/api/label"
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/exporters/metric/stdout"
 	"go.opentelemetry.io/otel/exporters/metric/test"
@@ -38,6 +37,7 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/minmaxsumcount"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 	aggtest "go.opentelemetry.io/otel/sdk/metric/aggregator/test"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type testFixture struct {
@@ -45,9 +45,10 @@ type testFixture struct {
 	ctx      context.Context
 	exporter *stdout.Exporter
 	output   *bytes.Buffer
+	resource *resource.Resource
 }
 
-func newFixture(t *testing.T, config stdout.Config) testFixture {
+func newFixture(t *testing.T, resource *resource.Resource, config stdout.Config) testFixture {
 	buf := &bytes.Buffer{}
 	config.Writer = buf
 	config.DoNotPrintTime = true
@@ -60,6 +61,7 @@ func newFixture(t *testing.T, config stdout.Config) testFixture {
 		ctx:      context.Background(),
 		exporter: exp,
 		output:   buf,
+		resource: resource,
 	}
 }
 
@@ -68,7 +70,7 @@ func (fix testFixture) Output() string {
 }
 
 func (fix testFixture) Export(checkpointSet export.CheckpointSet) {
-	err := fix.exporter.Export(fix.ctx, checkpointSet)
+	err := fix.exporter.Export(fix.ctx, fix.resource, checkpointSet)
 	if err != nil {
 		fix.t.Error("export failed: ", err)
 	}
@@ -94,7 +96,7 @@ func TestStdoutTimestamp(t *testing.T) {
 
 	before := time.Now()
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	ctx := context.Background()
 	desc := metric.NewDescriptor("test.name", metric.ObserverKind, core.Int64NumberKind)
@@ -104,7 +106,7 @@ func TestStdoutTimestamp(t *testing.T) {
 
 	checkpointSet.Add(&desc, lvagg)
 
-	if err := exporter.Export(ctx, checkpointSet); err != nil {
+	if err := exporter.Export(ctx, nil, checkpointSet); err != nil {
 		t.Fatal("Unexpected export error: ", err)
 	}
 
@@ -138,9 +140,9 @@ func TestStdoutTimestamp(t *testing.T) {
 }
 
 func TestStdoutCounterFormat(t *testing.T) {
-	fix := newFixture(t, stdout.Config{})
+	fix := newFixture(t, nil, stdout.Config{})
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	desc := metric.NewDescriptor("test.name", metric.CounterKind, core.Int64NumberKind)
 	cagg := sum.New()
@@ -155,9 +157,9 @@ func TestStdoutCounterFormat(t *testing.T) {
 }
 
 func TestStdoutLastValueFormat(t *testing.T) {
-	fix := newFixture(t, stdout.Config{})
+	fix := newFixture(t, nil, stdout.Config{})
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	desc := metric.NewDescriptor("test.name", metric.ObserverKind, core.Float64NumberKind)
 	lvagg := lastvalue.New()
@@ -172,9 +174,9 @@ func TestStdoutLastValueFormat(t *testing.T) {
 }
 
 func TestStdoutMinMaxSumCount(t *testing.T) {
-	fix := newFixture(t, stdout.Config{})
+	fix := newFixture(t, nil, stdout.Config{})
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	desc := metric.NewDescriptor("test.name", metric.MeasureKind, core.Float64NumberKind)
 	magg := minmaxsumcount.New(&desc)
@@ -190,11 +192,11 @@ func TestStdoutMinMaxSumCount(t *testing.T) {
 }
 
 func TestStdoutMeasureFormat(t *testing.T) {
-	fix := newFixture(t, stdout.Config{
+	fix := newFixture(t, nil, stdout.Config{
 		PrettyPrint: true,
 	})
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	desc := metric.NewDescriptor("test.name", metric.MeasureKind, core.Float64NumberKind)
 	magg := array.New()
@@ -246,9 +248,9 @@ func TestStdoutNoData(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 
-			fix := newFixture(t, stdout.Config{})
+			fix := newFixture(t, nil, stdout.Config{})
 
-			checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+			checkpointSet := test.NewCheckpointSet()
 
 			magg := tc
 			magg.Checkpoint(fix.ctx, &desc)
@@ -263,9 +265,9 @@ func TestStdoutNoData(t *testing.T) {
 }
 
 func TestStdoutLastValueNotSet(t *testing.T) {
-	fix := newFixture(t, stdout.Config{})
+	fix := newFixture(t, nil, stdout.Config{})
 
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	desc := metric.NewDescriptor("test.name", metric.ObserverKind, core.Float64NumberKind)
 	lvagg := lastvalue.New()
@@ -277,3 +279,55 @@ func TestStdoutLastValueNotSet(t *testing.T) {
 
 	require.Equal(t, `{"updates":null}`, fix.Output())
 }
+
+func TestStdoutResource(t *testing.T) {
+	type testCase struct {
+		expect string
+		res    *resource.Resource
+		attrs  []core.KeyValue
+	}
+	newCase := func(expect string, res *resource.Resource, attrs ...core.KeyValue) testCase {
+		return testCase{
+			expect: expect,
+			res:    res,
+			attrs:  attrs,
+		}
+	}
+	testCases := []testCase{
+		newCase("R1=V1,R2=V2,A=B,C=D",
+			resource.New(key.String("R1", "V1"), key.String("R2", "V2")),
+			key.String("A", "B"),
+			key.String("C", "D")),
+		newCase("R1=V1,R2=V2",
+			resource.New(key.String("R1", "V1"), key.String("R2", "V2")),
+		),
+		newCase("A=B,C=D",
+			nil,
+			key.String("A", "B"),
+			key.String("C", "D"),
+		),
+		// 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(key.String("R1", "V1"), key.String("R2", "V2")),
+			key.String("R1", "V3"),
+			key.String("R2", "V4")),
+	}
+
+	for _, tc := range testCases {
+		fix := newFixture(t, tc.res, stdout.Config{})
+
+		checkpointSet := test.NewCheckpointSet()
+
+		desc := metric.NewDescriptor("test.name", metric.ObserverKind, core.Float64NumberKind)
+		lvagg := lastvalue.New()
+		aggtest.CheckedUpdate(fix.t, lvagg, core.NewFloat64Number(123.456), &desc)
+		lvagg.Checkpoint(fix.ctx, &desc)
+
+		checkpointSet.Add(&desc, lvagg, tc.attrs...)
+
+		fix.Export(checkpointSet)
+
+		require.Equal(t, `{"updates":[{"name":"test.name{`+tc.expect+`}","last":123.456}]}`, fix.Output())
+	}
+}

exporters/metric/test/test.go

@@ -29,23 +29,26 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 )
 
+type mapkey struct {
+	desc     *metric.Descriptor
+	distinct label.Distinct
+}
+
 type CheckpointSet struct {
-	encoder label.Encoder
-	records map[string]export.Record
+	records map[mapkey]export.Record
 	updates []export.Record
 }
 
 // NewCheckpointSet returns a test CheckpointSet that new records could be added.
 // Records are grouped by their encoded labels.
-func NewCheckpointSet(encoder label.Encoder) *CheckpointSet {
+func NewCheckpointSet() *CheckpointSet {
 	return &CheckpointSet{
-		encoder: encoder,
-		records: make(map[string]export.Record),
+		records: make(map[mapkey]export.Record),
 	}
 }
 
 func (p *CheckpointSet) Reset() {
-	p.records = make(map[string]export.Record)
+	p.records = make(map[mapkey]export.Record)
 	p.updates = nil
 }
 
@@ -56,7 +59,10 @@ func (p *CheckpointSet) Reset() {
 func (p *CheckpointSet) Add(desc *metric.Descriptor, newAgg export.Aggregator, labels ...core.KeyValue) (agg export.Aggregator, added bool) {
 	elabels := label.NewSet(labels...)
 
-	key := desc.Name() + "_" + elabels.Encoded(p.encoder)
+	key := mapkey{
+		desc:     desc,
+		distinct: elabels.Equivalent(),
+	}
 	if record, ok := p.records[key]; ok {
 		return record.Aggregator(), false
 	}

exporters/otlp/internal/transform/metric.go

@@ -62,7 +62,7 @@ type result struct {
 
 // CheckpointSet transforms all records contained in a checkpoint into
 // batched OTLP ResourceMetrics.
-func CheckpointSet(ctx context.Context, cps export.CheckpointSet, numWorkers uint) ([]*metricpb.ResourceMetrics, error) {
+func CheckpointSet(ctx context.Context, resource *resource.Resource, cps export.CheckpointSet, numWorkers uint) ([]*metricpb.ResourceMetrics, error) {
 	records, errc := source(ctx, cps)
 
 	// Start a fixed number of goroutines to transform records.
@@ -72,7 +72,7 @@ func CheckpointSet(ctx context.Context, cps export.CheckpointSet, numWorkers uin
 	for i := uint(0); i < numWorkers; i++ {
 		go func() {
 			defer wg.Done()
-			transformer(ctx, records, transformed)
+			transformer(ctx, resource, records, transformed)
 		}()
 	}
 	go func() {
@@ -117,7 +117,7 @@ func source(ctx context.Context, cps export.CheckpointSet) (<-chan export.Record
 
 // transformer transforms records read from the passed in chan into
 // OTLP Metrics which are sent on the out chan.
-func transformer(ctx context.Context, in <-chan export.Record, out chan<- result) {
+func transformer(ctx context.Context, resource *resource.Resource, in <-chan export.Record, out chan<- result) {
 	for r := range in {
 		m, err := Record(r)
 		// Propagate errors, but do not send empty results.
@@ -125,7 +125,7 @@ func transformer(ctx context.Context, in <-chan export.Record, out chan<- result
 			continue
 		}
 		res := result{
-			Resource: r.Descriptor().Resource(),
+			Resource: resource,
 			Library:  r.Descriptor().LibraryName(),
 			Metric:   m,
 			Err:      err,

exporters/otlp/otlp.go

@@ -31,6 +31,7 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/internal/transform"
 	metricsdk "go.opentelemetry.io/otel/sdk/export/metric"
 	tracesdk "go.opentelemetry.io/otel/sdk/export/trace"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type Exporter struct {
@@ -211,7 +212,7 @@ func (e *Exporter) Stop() error {
 // Export implements the "go.opentelemetry.io/otel/sdk/export/metric".Exporter
 // interface. It transforms and batches metric Records into OTLP Metrics and
 // transmits them to the configured collector.
-func (e *Exporter) Export(parent context.Context, cps metricsdk.CheckpointSet) error {
+func (e *Exporter) Export(parent context.Context, resource *resource.Resource, cps metricsdk.CheckpointSet) error {
 	// Unify the parent context Done signal with the exporter stopCh.
 	ctx, cancel := context.WithCancel(parent)
 	defer cancel()
@@ -223,7 +224,7 @@ func (e *Exporter) Export(parent context.Context, cps metricsdk.CheckpointSet) e
 		}
 	}(ctx, cancel)
 
-	rms, err := transform.CheckpointSet(ctx, cps, e.c.numWorkers)
+	rms, err := transform.CheckpointSet(ctx, resource, cps, e.c.numWorkers)
 	if err != nil {
 		return err
 	}

exporters/otlp/otlp_metric_test.go

@@ -74,11 +74,12 @@ func (m checkpointSet) ForEach(fn func(metricsdk.Record) error) error {
 }
 
 type record struct {
-	name   string
-	mKind  metric.Kind
-	nKind  core.NumberKind
-	opts   []metric.Option
-	labels []core.KeyValue
+	name     string
+	mKind    metric.Kind
+	nKind    core.NumberKind
+	resource *resource.Resource
+	opts     []metric.Option
+	labels   []core.KeyValue
 }
 
 var (
@@ -145,14 +146,16 @@ func TestNoGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{},
+				nil,
+				nil,
 				append(baseKeyValues, cpuKey.Int(1)),
 			},
 			{
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{},
+				nil,
+				nil,
 				append(baseKeyValues, cpuKey.Int(2)),
 			},
 		},
@@ -191,7 +194,8 @@ func TestMeasureMetricGroupingExport(t *testing.T) {
 		"measure",
 		metric.MeasureKind,
 		core.Int64NumberKind,
-		[]metric.Option{},
+		nil,
+		nil,
 		append(baseKeyValues, cpuKey.Int(1)),
 	}
 	expected := []metricpb.ResourceMetrics{
@@ -264,7 +268,8 @@ func TestCountInt64MetricGroupingExport(t *testing.T) {
 		"int64-count",
 		metric.CounterKind,
 		core.Int64NumberKind,
-		[]metric.Option{},
+		nil,
+		nil,
 		append(baseKeyValues, cpuKey.Int(1)),
 	}
 	runMetricExportTests(
@@ -300,7 +305,8 @@ func TestCountUint64MetricGroupingExport(t *testing.T) {
 		"uint64-count",
 		metric.CounterKind,
 		core.Uint64NumberKind,
-		[]metric.Option{},
+		nil,
+		nil,
 		append(baseKeyValues, cpuKey.Int(1)),
 	}
 	runMetricExportTests(
@@ -349,7 +355,8 @@ func TestCountFloat64MetricGroupingExport(t *testing.T) {
 		"float64-count",
 		metric.CounterKind,
 		core.Float64NumberKind,
-		[]metric.Option{},
+		nil,
+		nil,
 		append(baseKeyValues, cpuKey.Int(1)),
 	}
 	runMetricExportTests(
@@ -401,28 +408,32 @@ func TestResourceMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{metric.WithResource(testInstA)},
+				testInstA,
+				nil,
 				append(baseKeyValues, cpuKey.Int(1)),
 			},
 			{
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{metric.WithResource(testInstA)},
+				testInstA,
+				nil,
 				append(baseKeyValues, cpuKey.Int(1)),
 			},
 			{
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{metric.WithResource(testInstA)},
+				testInstA,
+				nil,
 				append(baseKeyValues, cpuKey.Int(2)),
 			},
 			{
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
-				[]metric.Option{metric.WithResource(testInstB)},
+				testInstB,
+				nil,
 				append(baseKeyValues, cpuKey.Int(1)),
 			},
 		},
@@ -484,8 +495,8 @@ func TestResourceInstLibMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
+				testInstA,
 				[]metric.Option{
-					metric.WithResource(testInstA),
 					metric.WithLibraryName("couting-lib"),
 				},
 				append(baseKeyValues, cpuKey.Int(1)),
@@ -494,8 +505,8 @@ func TestResourceInstLibMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
+				testInstA,
 				[]metric.Option{
-					metric.WithResource(testInstA),
 					metric.WithLibraryName("couting-lib"),
 				},
 				append(baseKeyValues, cpuKey.Int(1)),
@@ -504,8 +515,8 @@ func TestResourceInstLibMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
+				testInstA,
 				[]metric.Option{
-					metric.WithResource(testInstA),
 					metric.WithLibraryName("couting-lib"),
 				},
 				append(baseKeyValues, cpuKey.Int(2)),
@@ -514,8 +525,8 @@ func TestResourceInstLibMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
+				testInstA,
 				[]metric.Option{
-					metric.WithResource(testInstA),
 					metric.WithLibraryName("summing-lib"),
 				},
 				append(baseKeyValues, cpuKey.Int(1)),
@@ -524,8 +535,8 @@ func TestResourceInstLibMetricGroupingExport(t *testing.T) {
 				"int64-count",
 				metric.CounterKind,
 				core.Int64NumberKind,
+				testInstB,
 				[]metric.Option{
-					metric.WithResource(testInstB),
 					metric.WithLibraryName("couting-lib"),
 				},
 				append(baseKeyValues, cpuKey.Int(1)),
@@ -617,7 +628,8 @@ func runMetricExportTest(t *testing.T, exp *Exporter, rs []record, expected []me
 	exp.metricExporter = msc
 	exp.started = true
 
-	var recs []metricsdk.Record
+	recs := map[label.Distinct][]metricsdk.Record{}
+	resources := map[label.Distinct]*resource.Resource{}
 	for _, r := range rs {
 		desc := metric.NewDescriptor(r.name, r.mKind, r.nKind, r.opts...)
 		labs := label.NewSet(r.labels...)
@@ -646,9 +658,14 @@ func runMetricExportTest(t *testing.T, exp *Exporter, rs []record, expected []me
 		}
 		agg.Checkpoint(ctx, &desc)
 
-		recs = append(recs, metricsdk.NewRecord(&desc, &labs, agg))
+		equiv := r.resource.Equivalent()
+		resources[equiv] = r.resource
+		recs[equiv] = append(recs[equiv], metricsdk.NewRecord(&desc, &labs, agg))
+	}
+	for equiv, records := range recs {
+		resource := resources[equiv]
+		assert.NoError(t, exp.Export(context.Background(), resource, checkpointSet{records: records}))
 	}
-	assert.NoError(t, exp.Export(context.Background(), checkpointSet{records: recs}))
 
 	// assert.ElementsMatch does not equate nested slices of different order,
 	// therefore this requires the top level slice to be broken down.
@@ -697,6 +714,8 @@ func TestEmptyMetricExport(t *testing.T) {
 	exp.metricExporter = msc
 	exp.started = true
 
+	resource := resource.New(key.String("R", "S"))
+
 	for _, test := range []struct {
 		records []metricsdk.Record
 		want    []metricpb.ResourceMetrics
@@ -711,7 +730,7 @@ func TestEmptyMetricExport(t *testing.T) {
 		},
 	} {
 		msc.Reset()
-		require.NoError(t, exp.Export(context.Background(), checkpointSet{records: test.records}))
+		require.NoError(t, exp.Export(context.Background(), resource, checkpointSet{records: test.records}))
 		assert.Equal(t, test.want, msc.ResourceMetrics())
 	}
 }

sdk/export/metric/metric.go

@@ -20,6 +20,7 @@ import (
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/label"
 	"go.opentelemetry.io/otel/api/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // Batcher is responsible for deciding which kind of aggregation to
@@ -160,9 +161,12 @@ type Exporter interface {
 	// The Context comes from the controller that initiated
 	// collection.
 	//
+	// The Resource contains common attributes that apply to all
+	// metric events in the SDK.
+	//
 	// The CheckpointSet interface refers to the Batcher that just
 	// completed collection.
-	Export(context.Context, CheckpointSet) error
+	Export(context.Context, *resource.Resource, CheckpointSet) error
 }
 
 // CheckpointSet allows a controller to access a complete checkpoint of

sdk/metric/config.go

@@ -14,8 +14,6 @@
 
 package metric
 
-import "go.opentelemetry.io/otel/sdk/resource"
-
 // Config contains configuration for an SDK.
 type Config struct {
 	// ErrorHandler is the function called when the SDK encounters an error.
@@ -23,10 +21,6 @@ type Config struct {
 	// This option can be overridden after instantiation of the SDK
 	// with the `SetErrorHandler` method.
 	ErrorHandler ErrorHandler
-
-	// Resource is the OpenTelemetry resource associated with all Meters
-	// created by the SDK.
-	Resource *resource.Resource
 }
 
 // Option is the interface that applies the value to a configuration option.
@@ -45,14 +39,3 @@ type errorHandlerOption ErrorHandler
 func (o errorHandlerOption) Apply(config *Config) {
 	config.ErrorHandler = ErrorHandler(o)
 }
-
-// WithResource sets the Resource configuration option of a Config.
-func WithResource(r *resource.Resource) Option {
-	return resourceOption{r}
-}
-
-type resourceOption struct{ *resource.Resource }
-
-func (o resourceOption) Apply(config *Config) {
-	config.Resource = o.Resource
-}

sdk/metric/config_test.go

@@ -19,9 +19,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-
-	"go.opentelemetry.io/otel/api/key"
-	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 func TestWithErrorHandler(t *testing.T) {
@@ -46,16 +43,3 @@ func TestWithErrorHandler(t *testing.T) {
 	c.ErrorHandler(err2)
 	assert.EqualError(t, *reg, err2.Error())
 }
-
-func TestWithResource(t *testing.T) {
-	r := resource.New(key.String("A", "a"))
-
-	c := &Config{}
-	WithResource(r).Apply(c)
-	assert.True(t, r.Equal(c.Resource))
-
-	// Ensure overwriting works.
-	c = &Config{Resource: &resource.Resource{}}
-	WithResource(r).Apply(c)
-	assert.Equal(t, r.Equivalent(), c.Resource.Equivalent())
-}

sdk/metric/controller/push/push.go

@@ -23,6 +23,7 @@ import (
 	"go.opentelemetry.io/otel/api/metric/registry"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	sdk "go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // Controller organizes a periodic push of metric data.
@@ -30,6 +31,7 @@ type Controller struct {
 	lock         sync.Mutex
 	collectLock  sync.Mutex
 	sdk          *sdk.SDK
+	resource     *resource.Resource
 	uniq         metric.MeterImpl
 	named        map[string]metric.Meter
 	errorHandler sdk.ErrorHandler
@@ -77,9 +79,10 @@ func New(batcher export.Batcher, exporter export.Exporter, period time.Duration,
 		opt.Apply(c)
 	}
 
-	impl := sdk.New(batcher, sdk.WithResource(c.Resource), sdk.WithErrorHandler(c.ErrorHandler))
+	impl := sdk.New(batcher, sdk.WithErrorHandler(c.ErrorHandler))
 	return &Controller{
 		sdk:          impl,
+		resource:     c.Resource,
 		uniq:         registry.NewUniqueInstrumentMeterImpl(impl),
 		named:        map[string]metric.Meter{},
 		errorHandler: c.ErrorHandler,
@@ -175,7 +178,7 @@ func (c *Controller) tick() {
 		mtx:      &c.collectLock,
 		delegate: c.batcher.CheckpointSet(),
 	}
-	err := c.exporter.Export(ctx, checkpointSet)
+	err := c.exporter.Export(ctx, c.resource, checkpointSet)
 	c.batcher.FinishedCollection()
 
 	if err != nil {

sdk/metric/controller/push/push_test.go

@@ -25,13 +25,13 @@ import (
 	"github.com/benbjohnson/clock"
 	"github.com/stretchr/testify/require"
 
-	"go.opentelemetry.io/otel/api/label"
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/exporters/metric/test"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregator"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type testBatcher struct {
@@ -68,7 +68,7 @@ var _ push.Clock = mockClock{}
 var _ push.Ticker = mockTicker{}
 
 func newFixture(t *testing.T) testFixture {
-	checkpointSet := test.NewCheckpointSet(label.DefaultEncoder())
+	checkpointSet := test.NewCheckpointSet()
 
 	batcher := &testBatcher{
 		t:             t,
@@ -115,7 +115,7 @@ func (b *testBatcher) getCounts() (checkpoints, finishes int) {
 	return b.checkpoints, b.finishes
 }
 
-func (e *testExporter) Export(_ context.Context, checkpointSet export.CheckpointSet) error {
+func (e *testExporter) Export(_ context.Context, _ *resource.Resource, checkpointSet export.CheckpointSet) error {
 	e.lock.Lock()
 	defer e.lock.Unlock()
 	e.exports++

sdk/metric/sdk.go

@@ -28,7 +28,6 @@ import (
 	api "go.opentelemetry.io/otel/api/metric"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregator"
-	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 type (
@@ -61,9 +60,6 @@ type (
 		// errorHandler supports delivering errors to the user.
 		errorHandler ErrorHandler
 
-		// resource represents the entity producing telemetry.
-		resource *resource.Resource
-
 		// asyncSortSlice has a single purpose - as a temporary
 		// place for sorting during labels creation to avoid
 		// allocation.  It is cleared after use.
@@ -323,7 +319,6 @@ func New(batcher export.Batcher, opts ...Option) *SDK {
 	return &SDK{
 		batcher:      batcher,
 		errorHandler: c.ErrorHandler,
-		resource:     c.Resource,
 	}
 }
 
@@ -467,16 +462,6 @@ func (m *SDK) checkpoint(ctx context.Context, descriptor *metric.Descriptor, rec
 	return 1
 }
 
-// Resource returns the Resource this SDK was created with describing the
-// entity for which it creates instruments for.
-//
-// Resource means that the SDK implements the Resourcer interface and
-// therefore all metric instruments it creates will inherit its
-// Resource by default unless explicitly overwritten.
-func (m *SDK) Resource() *resource.Resource {
-	return m.resource
-}
-
 // RecordBatch enters a batch of metric events.
 func (m *SDK) RecordBatch(ctx context.Context, kvs []core.KeyValue, measurements ...api.Measurement) {
 	// Labels will be computed the first time acquireHandle is

sdk/resource/resource.go

@@ -133,3 +133,13 @@ func (r *Resource) Len() int {
 	}
 	return r.labels.Len()
 }
+
+// Encoded returns an encoded representation of the resource by
+// applying a label encoder.  The result is cached by the underlying
+// label set.
+func (r *Resource) Encoded(enc label.Encoder) string {
+	if r == nil {
+		return ""
+	}
+	return r.labels.Encoded(enc)
+}