[API EPIC 4/4] Fix tests and examples (#2587)

* Empty All of the metrics dir

* Add instrument api with documentation

* Add a NoOp implementation.

* Updated to the new config standard

* Address PR comments

* This change moves components to sdk/metrics

The Moved components are:
- metric/metrictest
- metric/number
- metric/internal/registry
- metric/sdkapi

* The SDK changes necessary to satasify the new api

* This fixes the remaing tests.

* Update changelog

* refactor the Noop meter and instruments into one package.

* Renamed pkg.Instruments to pkg.InstrumentProvider

Co-authored-by: Aaron Clawson <MadVikingGod@users.noreply.github.com>

.github/dependabot.yml

@@ -227,15 +227,6 @@ updates:
     schedule:
       day: sunday
       interval: weekly
-  - package-ecosystem: gomod
-    directory: /internal/metric
-    labels:
-      - dependencies
-      - go
-      - "Skip Changelog"
-    schedule:
-      day: sunday
-      interval: weekly
   - package-ecosystem: gomod
     directory: /internal/tools
     labels:

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### ⚠️ Notice ⚠️
+
+This update is a breaking change of the unstable Metrics API. Code instrumented with the `go.opentelemetry.io/otel/metric` <= v0.27.0 will need to be modified.
+
 ### Added
 
 - Added support to configure the span limits with environment variables.
@@ -24,6 +28,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - For tracestate's members, prepend the new element and remove the oldest one, which is over capacity (#2592)
 - Add event and link drop counts to the exported data from the `oltptrace` exporter. (#2601)
+- The metrics API has been significantly changed. (#2587)
 - Unify path cleaning functionally in the `otlpmetric` and `otlptrace` config. (#2639)
 - Change the debug message from the `sdk/trace.BatchSpanProcessor` to reflect the count is cumulative. (#2640)
 

bridge/opencensus/aggregation.go

@@ -21,8 +21,8 @@ import (
 
 	"go.opencensus.io/metric/metricdata"
 
-	"go.opentelemetry.io/otel/metric/number"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/number"
 )
 
 var (

bridge/opencensus/exporter.go

@@ -27,13 +27,13 @@ import (
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/number"
-	"go.opentelemetry.io/otel/metric/sdkapi"
+	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/metric/unit"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/number"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 
@@ -170,17 +170,17 @@ func convertDescriptor(ocDescriptor metricdata.Descriptor) (sdkapi.Descriptor, e
 		// Includes TypeGaugeDistribution, TypeCumulativeDistribution, TypeSummary
 		return sdkapi.Descriptor{}, fmt.Errorf("%w; descriptor type: %v", errConversion, ocDescriptor.Type)
 	}
-	opts := []metric.InstrumentOption{
-		metric.WithDescription(ocDescriptor.Description),
+	opts := []instrument.Option{
+		instrument.WithDescription(ocDescriptor.Description),
 	}
 	switch ocDescriptor.Unit {
 	case metricdata.UnitDimensionless:
-		opts = append(opts, metric.WithUnit(unit.Dimensionless))
+		opts = append(opts, instrument.WithUnit(unit.Dimensionless))
 	case metricdata.UnitBytes:
-		opts = append(opts, metric.WithUnit(unit.Bytes))
+		opts = append(opts, instrument.WithUnit(unit.Bytes))
 	case metricdata.UnitMilliseconds:
-		opts = append(opts, metric.WithUnit(unit.Milliseconds))
+		opts = append(opts, instrument.WithUnit(unit.Milliseconds))
 	}
-	cfg := metric.NewInstrumentConfig(opts...)
+	cfg := instrument.NewConfig(opts...)
 	return sdkapi.NewDescriptor(ocDescriptor.Name, ikind, nkind, cfg.Description(), cfg.Unit()), nil
 }

bridge/opencensus/exporter_test.go

@@ -26,15 +26,15 @@ import (
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/metrictest"
-	"go.opentelemetry.io/otel/metric/number"
-	"go.opentelemetry.io/otel/metric/sdkapi"
+	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/metric/unit"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/controller/controllertest"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/metrictest"
+	"go.opentelemetry.io/otel/sdk/metric/number"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 
@@ -400,8 +400,8 @@ func TestConvertDescriptor(t *testing.T) {
 				"foo",
 				sdkapi.GaugeObserverInstrumentKind,
 				number.Int64Kind,
-				metric.WithDescription("bar"),
-				metric.WithUnit(unit.Bytes),
+				instrument.WithDescription("bar"),
+				instrument.WithUnit(unit.Bytes),
 			),
 		},
 		{
@@ -416,8 +416,8 @@ func TestConvertDescriptor(t *testing.T) {
 				"foo",
 				sdkapi.GaugeObserverInstrumentKind,
 				number.Float64Kind,
-				metric.WithDescription("bar"),
-				metric.WithUnit(unit.Milliseconds),
+				instrument.WithDescription("bar"),
+				instrument.WithUnit(unit.Milliseconds),
 			),
 		},
 		{
@@ -432,8 +432,8 @@ func TestConvertDescriptor(t *testing.T) {
 				"foo",
 				sdkapi.CounterObserverInstrumentKind,
 				number.Int64Kind,
-				metric.WithDescription("bar"),
-				metric.WithUnit(unit.Dimensionless),
+				instrument.WithDescription("bar"),
+				instrument.WithUnit(unit.Dimensionless),
 			),
 		},
 		{
@@ -448,8 +448,8 @@ func TestConvertDescriptor(t *testing.T) {
 				"foo",
 				sdkapi.CounterObserverInstrumentKind,
 				number.Float64Kind,
-				metric.WithDescription("bar"),
-				metric.WithUnit(unit.Dimensionless),
+				instrument.WithDescription("bar"),
+				instrument.WithUnit(unit.Dimensionless),
 			),
 		},
 		{

example/prometheus/main.go

@@ -25,7 +25,7 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/exporters/prometheus"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/global"
+	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/histogram"
 	controller "go.opentelemetry.io/otel/sdk/metric/controller/basic"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
@@ -35,6 +35,9 @@ import (
 
 var (
 	lemonsKey = attribute.Key("ex.com/lemons")
+
+	// TODO Bring back Global package
+	meterProvider metric.MeterProvider
 )
 
 func initMeter() {
@@ -54,7 +57,9 @@ func initMeter() {
 	if err != nil {
 		log.Panicf("failed to initialize prometheus exporter %v", err)
 	}
-	global.SetMeterProvider(exporter.MeterProvider())
+	// TODO Bring back Global package
+	// global.SetMeterProvider(exporter.MeterProvider())
+	meterProvider = exporter.MeterProvider()
 
 	http.HandleFunc("/", exporter.ServeHTTP)
 	go func() {
@@ -67,23 +72,33 @@ func initMeter() {
 func main() {
 	initMeter()
 
-	meter := global.Meter("ex.com/basic")
+	// TODO Bring back Global package
+	// meter := global.Meter("ex.com/basic")
+	meter := meterProvider.Meter("ex.com/basic")
 	observerLock := new(sync.RWMutex)
 	observerValueToReport := new(float64)
 	observerLabelsToReport := new([]attribute.KeyValue)
-	cb := func(_ context.Context, result metric.Float64ObserverResult) {
+
+	gaugeObserver, err := meter.AsyncFloat64().Gauge("ex.com.one")
+	if err != nil {
+		log.Panicf("failed to initialize instrument: %v", err)
+	}
+	_ = meter.RegisterCallback([]instrument.Asynchronous{gaugeObserver}, func(ctx context.Context) {
 		(*observerLock).RLock()
 		value := *observerValueToReport
 		labels := *observerLabelsToReport
 		(*observerLock).RUnlock()
-		result.Observe(value, labels...)
-	}
-	_ = metric.Must(meter).NewFloat64GaugeObserver("ex.com.one", cb,
-		metric.WithDescription("A GaugeObserver set to 1.0"),
-	)
+		gaugeObserver.Observe(ctx, value, labels...)
+	})
 
-	histogram := metric.Must(meter).NewFloat64Histogram("ex.com.two")
-	counter := metric.Must(meter).NewFloat64Counter("ex.com.three")
+	histogram, err := meter.SyncFloat64().Histogram("ex.com.two")
+	if err != nil {
+		log.Panicf("failed to initialize instrument: %v", err)
+	}
+	counter, err := meter.SyncFloat64().Counter("ex.com.three")
+	if err != nil {
+		log.Panicf("failed to initialize instrument: %v", err)
+	}
 
 	commonLabels := []attribute.KeyValue{lemonsKey.Int(10), attribute.String("A", "1"), attribute.String("B", "2"), attribute.String("C", "3")}
 	notSoCommonLabels := []attribute.KeyValue{lemonsKey.Int(13)}
@@ -94,38 +109,27 @@ func main() {
 	*observerValueToReport = 1.0
 	*observerLabelsToReport = commonLabels
 	(*observerLock).Unlock()
-	meter.RecordBatch(
-		ctx,
-		commonLabels,
-		histogram.Measurement(2.0),
-		counter.Measurement(12.0),
-	)
+
+	histogram.Record(ctx, 2.0, commonLabels...)
+	counter.Add(ctx, 12.0, commonLabels...)
 
 	time.Sleep(5 * time.Second)
 
 	(*observerLock).Lock()
 	*observerValueToReport = 1.0
 	*observerLabelsToReport = notSoCommonLabels
 	(*observerLock).Unlock()
-	meter.RecordBatch(
-		ctx,
-		notSoCommonLabels,
-		histogram.Measurement(2.0),
-		counter.Measurement(22.0),
-	)
+	histogram.Record(ctx, 2.0, notSoCommonLabels...)
+	counter.Add(ctx, 22.0, notSoCommonLabels...)
 
 	time.Sleep(5 * time.Second)
 
 	(*observerLock).Lock()
 	*observerValueToReport = 13.0
 	*observerLabelsToReport = commonLabels
 	(*observerLock).Unlock()
-	meter.RecordBatch(
-		ctx,
-		commonLabels,
-		histogram.Measurement(12.0),
-		counter.Measurement(13.0),
-	)
+	histogram.Record(ctx, 12.0, commonLabels...)
+	counter.Add(ctx, 13.0, commonLabels...)
 
 	fmt.Println("Example finished updating, please visit :2222")
 

exporters/otlp/otlpmetric/exporter.go

@@ -20,9 +20,9 @@ import (
 	"sync"
 
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/metrictransform"
-	"go.opentelemetry.io/otel/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/resource"
 )
 

exporters/otlp/otlpmetric/exporter_test.go

@@ -29,16 +29,16 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/metrictransform"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/metrictest"
-	"go.opentelemetry.io/otel/metric/number"
-	"go.opentelemetry.io/otel/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/histogram"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/metrictest"
+	"go.opentelemetry.io/otel/sdk/metric/number"
 	"go.opentelemetry.io/otel/sdk/metric/processor/processortest"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/resource"
 	commonpb "go.opentelemetry.io/proto/otlp/common/v1"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"

exporters/otlp/otlpmetric/internal/metrictransform/metric.go

@@ -24,10 +24,10 @@ import (
 	"sync"
 	"time"
 
-	"go.opentelemetry.io/otel/metric/number"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/number"
 	"go.opentelemetry.io/otel/sdk/resource"
 	commonpb "go.opentelemetry.io/proto/otlp/common/v1"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"

exporters/otlp/otlpmetric/internal/metrictransform/metric_test.go

@@ -25,14 +25,14 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/metric/metrictest"
-	"go.opentelemetry.io/otel/metric/number"
-	"go.opentelemetry.io/otel/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/lastvalue"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 	"go.opentelemetry.io/otel/sdk/metric/export"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/metrictest"
+	"go.opentelemetry.io/otel/sdk/metric/number"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 	commonpb "go.opentelemetry.io/proto/otlp/common/v1"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )

exporters/otlp/otlpmetric/internal/otlpmetrictest/data.go

@@ -20,13 +20,13 @@ import (
 	"time"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/metric/metrictest"
-	"go.opentelemetry.io/otel/metric/number"
-	"go.opentelemetry.io/otel/metric/sdkapi"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/sum"
 	"go.opentelemetry.io/otel/sdk/metric/export"
+	"go.opentelemetry.io/otel/sdk/metric/metrictest"
+	"go.opentelemetry.io/otel/sdk/metric/number"
 	"go.opentelemetry.io/otel/sdk/metric/processor/processortest"
+	"go.opentelemetry.io/otel/sdk/metric/sdkapi"
 )
 
 // OneRecordReader is a Reader that returns just one