runtimevar: switch to utilising opentelemetry

internal/otel/metrics.go

@@ -27,7 +27,8 @@ import (
 // Units are encoded according to the case-sensitive abbreviations from the
 // Unified Code for Units of Measure: http://unitsofmeasure.org/ucum.html.
 const (
-	unitMilliseconds = "ms"
+	unitDimensionless = "1"
+	unitMilliseconds  = "ms"
 )
 
 var (
@@ -108,3 +109,40 @@ func LatencyMeasure(pkg string, provider string) metric.Float64Histogram {
 
 	return m
 }
+
+func DimensionlessMeasure(pkg string, provider string, meterName string, description string) metric.Int64Counter {
+
+	attrs := []attribute.KeyValue{
+		packageKey.String(pkg),
+		providerKey.String(provider),
+	}
+
+	pkgMeter := otel.Meter(pkg, metric.WithInstrumentationAttributes(attrs...))
+
+	m, err := pkgMeter.Int64Counter(pkg+meterName, metric.WithDescription(description), metric.WithUnit(unitDimensionless))
+
+	if err != nil {
+		// The only possible errors are from invalid key or value names,
+		// and those are programming errors that will be found during testing.
+		panic(fmt.Sprintf("fullName=%q, provider=%q: %v", pkg, pkgMeter, err))
+	}
+	return m
+}
+
+func CounterView(pkg string, meterName string, description string) []sdkmetric.View {
+	return []sdkmetric.View{
+		// View for gauge counts.
+		func(inst sdkmetric.Instrument) (sdkmetric.Stream, bool) {
+			if inst.Kind == sdkmetric.InstrumentKindCounter {
+				if inst.Name == pkg+meterName {
+					return sdkmetric.Stream{
+						Name:        inst.Name,
+						Description: description,
+						Aggregation: sdkmetric.DefaultAggregationSelector(sdkmetric.InstrumentKindCounter),
+					}, true
+				}
+			}
+			return sdkmetric.Stream{}, false
+		},
+	}
+}

internal/testing/oteltest/diff.go

@@ -67,8 +67,8 @@ func formatCall(c *Call) string {
 // provider is the name of the provider used (e.g., "aws").
 // want is the list of expected calls.
 func Diff(gotSpans []sdktrace.ReadOnlySpan, gotMetrics []metricdata.ScopeMetrics, namePrefix, provider string, want []Call) string {
-	ds := diffSpans(gotSpans, namePrefix, want)
-	dc := diffCounts(gotMetrics, namePrefix, provider, want)
+	ds := DiffSpans(gotSpans, namePrefix, want)
+	dc := DiffMetrics(gotMetrics, namePrefix, provider, want)
 	if len(ds) > 0 {
 		ds = "trace: " + ds + "\n"
 	}
@@ -86,7 +86,7 @@ func mapStatusCode(code gcerrors.ErrorCode) codes.Code {
 	return codes.Error
 }
 
-func diffSpans(got []sdktrace.ReadOnlySpan, prefix string, want []Call) string {
+func DiffSpans(got []sdktrace.ReadOnlySpan, prefix string, want []Call) string {
 	var diffs []string
 	add := func(i int, g sdktrace.ReadOnlySpan, w *Call) {
 		diffs = append(diffs, fmt.Sprintf("#%d: got %s, want %s", i, formatSpanData(g), formatCall(w)))
@@ -117,15 +117,15 @@ func diffSpans(got []sdktrace.ReadOnlySpan, prefix string, want []Call) string {
 	return strings.Join(diffs, "\n")
 }
 
-func diffCounts(got []metricdata.ScopeMetrics, prefix, provider string, wantCalls []Call) string {
+func DiffMetrics(got []metricdata.ScopeMetrics, prefix, provider string, wantCalls []Call) string {
 	// OTel metric data is structured. We need to iterate through it to find the
 	// relevant metric data points and their attributes.
 	var diffs []string
 	gotTags := map[string]bool{} // map of canonicalized data point attributes
 
 	// Helper to convert attribute.Set to a canonical string key
 	attrSetToCanonicalString := func(set attribute.Set) string {
-		// Get key-value pairs, sort them, and format into a stable string
+		// Get key-value pairs, sort them, and format into a stable string.
 		attrs := make([]attribute.KeyValue, 0, set.Len())
 		iter := set.Iter()
 		for iter.Next() {
@@ -143,45 +143,69 @@ func diffCounts(got []metricdata.ScopeMetrics, prefix, provider string, wantCall
 		return strings.Join(parts, ",")
 	}
 
-	// Iterate through all collected metrics to find relevant data points
-	for _, sm := range got {
+	// Helper function to collect relevant attributes for tag comparison.
+	processAtrributes := func(attrSets ...attribute.Set) {
+
+		var requiredAttributes []attribute.KeyValue
+		for _, attrSet := range attrSets {
+			for _, a := range attrSet.ToSlice() {
+				if a.Key == providerKey {
+					requiredAttributes = append(requiredAttributes, a)
+				}
+
+				if a.Key == methodKey {
+					requiredAttributes = append(requiredAttributes, a)
+				}
 
-		providerVal, providerOK := sm.Scope.Attributes.Value(providerKey)
+				if a.Key == statusKey {
+					requiredAttributes = append(requiredAttributes, a)
+				}
+			}
+		}
+
+		if len(requiredAttributes) > 0 {
+			gotTags[attrSetToCanonicalString(attribute.NewSet(requiredAttributes...))] = true
+		}
+
+	}
+
+	// Iterate through all collected metrics to find relevant data points.
+	for _, sm := range got {
 
 		for _, m := range sm.Metrics {
-			// gocloud usually records counts. Check for Sum metrics.
-			if sum, ok := m.Data.(metricdata.Sum[float64]); ok {
-				for _, dp := range sum.DataPoints {
-					methodVal, methodOK := dp.Attributes.Value(methodKey)
-					statusVal, statusOK := dp.Attributes.Value(statusKey)
-
-					if providerOK && methodOK && statusOK {
-
-						attrSet := attribute.NewSet(
-							providerKey.String(providerVal.AsString()),
-							methodKey.String(methodVal.AsString()),
-							statusKey.String(statusVal.AsString()),
-						)
-
-						gotTags[attrSetToCanonicalString(attrSet)] = true
-					}
+
+			// Using a switch will allow us accommodate other types of metrics.
+			switch v := m.Data.(type) {
+			case metricdata.Sum[int64]:
+				// Handle int64 Sum metrics.
+				for _, dp := range v.DataPoints {
+					processAtrributes(sm.Scope.Attributes, dp.Attributes)
 				}
+			case metricdata.Sum[float64]:
+				// gocloud usually records counts. Check for Sum metrics.
+				for _, dp := range v.DataPoints {
+					processAtrributes(sm.Scope.Attributes, dp.Attributes)
+				}
+			default:
+				// Handle any other types of metrics.
+				processAtrributes(sm.Scope.Attributes)
 			}
 		}
 	}
 
-	// Check that each wanted call has a corresponding metric data point with the correct attributes
+	// Check that each wanted call has a corresponding metric data point with the correct attributes.
 	for _, wc := range wantCalls {
-		// Construct the expected set of attributes for the wanted call
-		expectedAttributes := attribute.NewSet(
-			methodKey.String(prefix+"."+wc.Method),
-			providerKey.String(provider),
-			// gcerrors code is usually formatted as a string status in the attribute
-			statusKey.String(fmt.Sprint(wc.Code)),
-		)
-
-		// Canonicalize the expected attributes to check against the collected ones
-		expectedKey := attrSetToCanonicalString(expectedAttributes)
+		// Construct the expected set of attributes for the wanted call.
+		expectedAttributes := []attribute.KeyValue{providerKey.String(provider)}
+
+		if wc.Method != "" {
+			expectedAttributes = append(expectedAttributes,
+				methodKey.String(prefix+"."+wc.Method),
+				statusKey.String(fmt.Sprint(wc.Code)))
+		}
+
+		// Canonicalize the expected attributes to check against the collected ones.
+		expectedKey := attrSetToCanonicalString(attribute.NewSet(expectedAttributes...))
 
 		if !gotTags[expectedKey] {
 			diffs = append(diffs, fmt.Sprintf("missing metric data point with attributes %q", expectedKey))

runtimevar/etcdvar/go.mod

@@ -48,7 +48,6 @@ require (
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/go-replayers/grpcreplay v1.3.0 // indirect
@@ -62,7 +61,6 @@ require (
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	go.etcd.io/etcd/api/v3 v3.5.21 // indirect
 	go.etcd.io/etcd/client/pkg/v3 v3.5.21 // indirect
-	go.opencensus.io v0.24.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.60.0 // indirect
 	go.opentelemetry.io/otel v1.37.0 // indirect

runtimevar/etcdvar/go.sum

@@ -143,8 +143,6 @@ github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfU
 github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/groupcache v0.0.0-20191227052852-215e87163ea7/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
-github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 h1:f+oWsMOmNPc8JmEHVZIycC7hBoQxHH9pNKQORJNozsQ=
-github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8/go.mod h1:wcDNUvekVysuuOpQKo3191zZyTpiI6se1N1ULghS0sw=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.2.0/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/mock v1.3.1/go.mod h1:sBzyDLLjw3U8JLTeZvSv8jJB+tU5PVekmnlKIyFUx0Y=
@@ -252,14 +250,9 @@ github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFR
 github.com/spiffe/go-spiffe/v2 v2.5.0 h1:N2I01KCUkv1FAjZXJMwh95KK1ZIQLYbPfhaxw8WS0hE=
 github.com/spiffe/go-spiffe/v2 v2.5.0/go.mod h1:P+NxobPc6wXhVtINNtFjNWGBTreew1GBUCwT2wPmb7g=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -285,8 +278,6 @@ go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.5/go.mod h1:5pWMHQbX5EPX2/62yrJeAkowc+lfs/XD7Uxpq3pI6kk=
 go.opencensus.io v0.23.0/go.mod h1:XItmlyltB5F7CS4xOC1DcqMoFqwtC6OG2xF7mCv7P7E=
-go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
-go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
 go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
 go.opentelemetry.io/contrib/detectors/gcp v1.36.0 h1:F7q2tNlCaHY9nMKHR6XH9/qkp8FktLnIcy6jJNyOCQw=

runtimevar/oc_test.go → runtimevar/otel_test.go

@@ -1,4 +1,4 @@
-// Copyright 2019 The Go Cloud Development Kit Authors
+// Copyright 2019-2025 The Go Cloud Development Kit Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -16,19 +16,22 @@ package runtimevar_test
 
 import (
 	"context"
-	"testing"
-
-	"go.opencensus.io/stats/view"
-	"gocloud.dev/internal/oc"
-	"gocloud.dev/internal/testing/octest"
+	"gocloud.dev/gcerrors"
+	"gocloud.dev/internal/testing/oteltest"
 	"gocloud.dev/runtimevar"
 	"gocloud.dev/runtimevar/constantvar"
+	"testing"
 )
 
-func TestOpenCensus(t *testing.T) {
+const (
+	pkgName = "gocloud.dev/runtimevar"
+	driver  = "gocloud.dev/runtimevar/constantvar"
+)
+
+func TestOpenTelemetry(t *testing.T) {
 	ctx := context.Background()
-	te := octest.NewTestExporter(runtimevar.OpenCensusViews)
-	defer te.Unregister()
+	te := oteltest.NewTestExporter(t, runtimevar.OpenTelemetryViews)
+	defer te.Shutdown(ctx)
 
 	v := constantvar.New(1)
 	defer v.Close()
@@ -39,18 +42,13 @@ func TestOpenCensus(t *testing.T) {
 	cancel()
 	_, _ = v.Watch(cctx)
 
-	seen := false
-	const driver = "gocloud.dev/runtimevar/constantvar"
-	for _, row := range te.Counts() {
-		if _, ok := row.Data.(*view.CountData); !ok {
-			continue
-		}
-		if row.Tags[0].Key == oc.ProviderKey && row.Tags[0].Value == driver {
-			seen = true
-			break
-		}
-	}
-	if !seen {
-		t.Errorf("did not see count row with provider=%s", driver)
+	// Check metrics - during migration, we may need to look for different metric names.
+	metrics := te.GetMetrics(ctx)
+
+	diff := oteltest.DiffMetrics(metrics, pkgName, driver, []oteltest.Call{
+		{Method: "", Code: gcerrors.OK},
+	})
+	if diff != "" {
+		t.Error(diff)
 	}
 }