prometheus exporter convert instrumentation scope to otel_scope_info …

…metric

Signed-off-by: Ziqi Zhao <zhaoziqi9146@gmail.com>

exporters/prometheus/config.go

@@ -26,6 +26,7 @@ type config struct {
 	disableTargetInfo bool
 	withoutUnits      bool
 	aggregation       metric.AggregationSelector
+	disableScopeInfo  bool
 }
 
 // newConfig creates a validated config configured with options.
@@ -105,3 +106,13 @@ func WithoutUnits() Option {
 		return cfg
 	})
 }
+
+// WithoutScopeInfo configures the Exporter to not export the resource otel_scope_info metric.
+// If not specified, the Exporter will create a otel_scope_info metric containing
+// the metrics' Instrumentation Scope, and also add labels about Instrumentation Scope to all metric point
+func WithoutScopeInfo() Option {
+	return optionFunc(func(cfg config) config {
+		cfg.disableScopeInfo = true
+		return cfg
+	})
+}

exporters/prometheus/exporter.go

@@ -28,6 +28,7 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric/unit"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	"go.opentelemetry.io/otel/sdk/resource"
@@ -36,6 +37,13 @@ import (
 const (
 	targetInfoMetricName  = "target_info"
 	targetInfoDescription = "Target metadata"
+
+	scopeInfoMetricName  = "otel_scope_info"
+	scopeInfoDescription = "Instrumentation Scope metadata"
+)
+
+var (
+	scopeInfoKeys = []string{"otel_scope_name", "otel_scope_version"}
 )
 
 // Exporter is a Prometheus Exporter that embeds the OTel metric.Reader
@@ -53,7 +61,9 @@ type collector struct {
 	disableTargetInfo    bool
 	withoutUnits         bool
 	targetInfo           prometheus.Metric
+	disableScopeInfo     bool
 	createTargetInfoOnce sync.Once
+	scopeInfos           map[instrumentation.Scope]prometheus.Metric
 }
 
 // prometheus counters MUST have a _total suffix:
@@ -73,6 +83,8 @@ func New(opts ...Option) (*Exporter, error) {
 		reader:            reader,
 		disableTargetInfo: cfg.disableTargetInfo,
 		withoutUnits:      cfg.withoutUnits,
+		disableScopeInfo:  cfg.disableScopeInfo,
+		scopeInfos:        make(map[instrumentation.Scope]prometheus.Metric),
 	}
 
 	if err := cfg.registerer.Register(collector); err != nil {
@@ -119,27 +131,48 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
 		ch <- c.targetInfo
 	}
 	for _, scopeMetrics := range metrics.ScopeMetrics {
+		var keys, values = []string{}, []string{}
+
+		if !c.disableScopeInfo {
+			var scopeInfo prometheus.Metric
+			if _, exist := c.scopeInfos[scopeMetrics.Scope]; exist {
+				scopeInfo = c.scopeInfos[scopeMetrics.Scope]
+			} else {
+				scopeInfo, err = createScopeInfoMetric(scopeMetrics.Scope)
+				if err != nil {
+					otel.Handle(err)
+				}
+				c.scopeInfos[scopeMetrics.Scope] = scopeInfo
+			}
+			ch <- scopeInfo
+			keys = append(keys, scopeInfoKeys...)
+			values = append(values, getScopeKeyValues(scopeMetrics.Scope)...)
+		}
+
 		for _, m := range scopeMetrics.Metrics {
 			switch v := m.Data.(type) {
 			case metricdata.Histogram:
-				addHistogramMetric(ch, v, m, c.getName(m))
+				addHistogramMetric(ch, v, m, keys, values, c.getName(m))
 			case metricdata.Sum[int64]:
-				addSumMetric(ch, v, m, c.getName(m))
+				addSumMetric(ch, v, m, keys, values, c.getName(m))
 			case metricdata.Sum[float64]:
-				addSumMetric(ch, v, m, c.getName(m))
+				addSumMetric(ch, v, m, keys, values, c.getName(m))
 			case metricdata.Gauge[int64]:
-				addGaugeMetric(ch, v, m, c.getName(m))
+				addGaugeMetric(ch, v, m, keys, values, c.getName(m))
 			case metricdata.Gauge[float64]:
-				addGaugeMetric(ch, v, m, c.getName(m))
+				addGaugeMetric(ch, v, m, keys, values, c.getName(m))
 			}
 		}
 	}
 }
 
-func addHistogramMetric(ch chan<- prometheus.Metric, histogram metricdata.Histogram, m metricdata.Metrics, name string) {
+func addHistogramMetric(ch chan<- prometheus.Metric, histogram metricdata.Histogram, m metricdata.Metrics, ks, vs []string, name string) {
 	// TODO(https://github.com/open-telemetry/opentelemetry-go/issues/3163): support exemplars
 	for _, dp := range histogram.DataPoints {
 		keys, values := getAttrs(dp.Attributes)
+		keys = append(keys, ks...)
+		values = append(values, vs...)
+
 		desc := prometheus.NewDesc(name, m.Description, keys, nil)
 		buckets := make(map[float64]uint64, len(dp.Bounds))
 
@@ -157,7 +190,7 @@ func addHistogramMetric(ch chan<- prometheus.Metric, histogram metricdata.Histog
 	}
 }
 
-func addSumMetric[N int64 | float64](ch chan<- prometheus.Metric, sum metricdata.Sum[N], m metricdata.Metrics, name string) {
+func addSumMetric[N int64 | float64](ch chan<- prometheus.Metric, sum metricdata.Sum[N], m metricdata.Metrics, ks, vs []string, name string) {
 	valueType := prometheus.CounterValue
 	if !sum.IsMonotonic {
 		valueType = prometheus.GaugeValue
@@ -168,6 +201,9 @@ func addSumMetric[N int64 | float64](ch chan<- prometheus.Metric, sum metricdata
 	}
 	for _, dp := range sum.DataPoints {
 		keys, values := getAttrs(dp.Attributes)
+		keys = append(keys, ks...)
+		values = append(values, vs...)
+
 		desc := prometheus.NewDesc(name, m.Description, keys, nil)
 		m, err := prometheus.NewConstMetric(desc, valueType, float64(dp.Value), values...)
 		if err != nil {
@@ -178,9 +214,12 @@ func addSumMetric[N int64 | float64](ch chan<- prometheus.Metric, sum metricdata
 	}
 }
 
-func addGaugeMetric[N int64 | float64](ch chan<- prometheus.Metric, gauge metricdata.Gauge[N], m metricdata.Metrics, name string) {
+func addGaugeMetric[N int64 | float64](ch chan<- prometheus.Metric, gauge metricdata.Gauge[N], m metricdata.Metrics, ks, vs []string, name string) {
 	for _, dp := range gauge.DataPoints {
 		keys, values := getAttrs(dp.Attributes)
+		keys = append(keys, ks...)
+		values = append(values, vs...)
+
 		desc := prometheus.NewDesc(name, m.Description, keys, nil)
 		m, err := prometheus.NewConstMetric(desc, prometheus.GaugeValue, float64(dp.Value), values...)
 		if err != nil {
@@ -226,6 +265,21 @@ func (c *collector) createInfoMetric(name, description string, res *resource.Res
 	return prometheus.NewConstMetric(desc, prometheus.GaugeValue, float64(1), values...)
 }
 
+func getScopeKeyValues(scope instrumentation.Scope) (values []string) {
+	values = []string{
+		scope.Name,
+		scope.Version,
+	}
+	return
+}
+
+func createScopeInfoMetric(scope instrumentation.Scope) (prometheus.Metric, error) {
+	values := getScopeKeyValues(scope)
+
+	desc := prometheus.NewDesc(scopeInfoMetricName, scopeInfoDescription, scopeInfoKeys, nil)
+	return prometheus.NewConstMetric(desc, prometheus.GaugeValue, float64(1), values...)
+}
+
 func sanitizeRune(r rune) rune {
 	if unicode.IsLetter(r) || unicode.IsDigit(r) || r == ':' || r == '_' {
 		return r

exporters/prometheus/exporter_test.go

@@ -262,7 +262,10 @@ func TestPrometheusExporter(t *testing.T) {
 				metric.WithResource(res),
 				metric.WithReader(exporter, customBucketsView, defaultView),
 			)
-			meter := provider.Meter("testmeter")
+			meter := provider.Meter(
+				"testmeter",
+				otelmetric.WithInstrumentationVersion("v0.1.0"),
+			)
 
 			tc.recordMetrics(ctx, meter)
 

exporters/prometheus/testdata/counter.txt

@@ -1,7 +1,10 @@
 # HELP foo_milliseconds_total a simple counter
 # TYPE foo_milliseconds_total counter
-foo_milliseconds_total{A="B",C="D",E="true",F="42"} 24.3
-foo_milliseconds_total{A="D",C="B",E="true",F="42"} 5
+foo_milliseconds_total{A="B",C="D",E="true",F="42",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 24.3
+foo_milliseconds_total{A="D",C="B",E="true",F="42",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 5
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/custom_resource.txt

@@ -1,6 +1,9 @@
 # HELP foo_total a simple counter
 # TYPE foo_total counter
-foo_total{A="B",C="D",E="true",F="42"} 24.3
+foo_total{A="B",C="D",E="true",F="42",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 24.3
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{A="B",C="D",service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/empty_resource.txt

@@ -1,6 +1,9 @@
 # HELP foo_total a simple counter
 # TYPE foo_total counter
-foo_total{A="B",C="D",E="true",F="42"} 24.3
+foo_total{A="B",C="D",E="true",F="42",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 24.3
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info 1

exporters/prometheus/testdata/gauge.txt

@@ -1,6 +1,9 @@
 # HELP bar_ratio a fun little gauge
 # TYPE bar_ratio gauge
-bar_ratio{A="B",C="D"} .75
+bar_ratio{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} .75
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/histogram.txt

@@ -1,18 +1,21 @@
 # HELP histogram_baz_bytes a very nice histogram
 # TYPE histogram_baz_bytes histogram
-histogram_baz_bytes_bucket{A="B",C="D",le="0"} 0
-histogram_baz_bytes_bucket{A="B",C="D",le="5"} 0
-histogram_baz_bytes_bucket{A="B",C="D",le="10"} 1
-histogram_baz_bytes_bucket{A="B",C="D",le="25"} 2
-histogram_baz_bytes_bucket{A="B",C="D",le="50"} 2
-histogram_baz_bytes_bucket{A="B",C="D",le="75"} 2
-histogram_baz_bytes_bucket{A="B",C="D",le="100"} 2
-histogram_baz_bytes_bucket{A="B",C="D",le="250"} 4
-histogram_baz_bytes_bucket{A="B",C="D",le="500"} 4
-histogram_baz_bytes_bucket{A="B",C="D",le="1000"} 4
-histogram_baz_bytes_bucket{A="B",C="D",le="+Inf"} 4
-histogram_baz_bytes_sum{A="B",C="D"} 236
-histogram_baz_bytes_count{A="B",C="D"} 4
+histogram_baz_bytes_bucket{A="B",C="D",le="0",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 0
+histogram_baz_bytes_bucket{A="B",C="D",le="5",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 0
+histogram_baz_bytes_bucket{A="B",C="D",le="10",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+histogram_baz_bytes_bucket{A="B",C="D",le="25",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 2
+histogram_baz_bytes_bucket{A="B",C="D",le="50",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 2
+histogram_baz_bytes_bucket{A="B",C="D",le="75",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 2
+histogram_baz_bytes_bucket{A="B",C="D",le="100",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 2
+histogram_baz_bytes_bucket{A="B",C="D",le="250",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 4
+histogram_baz_bytes_bucket{A="B",C="D",le="500",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 4
+histogram_baz_bytes_bucket{A="B",C="D",le="1000",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 4
+histogram_baz_bytes_bucket{A="B",C="D",le="+Inf",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 4
+histogram_baz_bytes_sum{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 236
+histogram_baz_bytes_count{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 4
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/sanitized_labels.txt

@@ -1,6 +1,9 @@
 # HELP foo_total a sanitary counter
 # TYPE foo_total counter
-foo_total{A_B="Q",C_D="Y;Z"} 24.3
+foo_total{A_B="Q",C_D="Y;Z",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 24.3
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/sanitized_names.txt

@@ -1,32 +1,35 @@
 # HELP bar a fun little gauge
 # TYPE bar gauge
-bar{A="B",C="D"} 75
+bar{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 75
 # HELP _0invalid_counter_name_total a counter with an invalid name
 # TYPE _0invalid_counter_name_total counter
-_0invalid_counter_name_total{A="B",C="D"} 100
+_0invalid_counter_name_total{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 100
 # HELP invalid_gauge_name a gauge with an invalid name
 # TYPE invalid_gauge_name gauge
-invalid_gauge_name{A="B",C="D"} 100
+invalid_gauge_name{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 100
 # HELP invalid_hist_name a histogram with an invalid name
 # TYPE invalid_hist_name histogram
-invalid_hist_name_bucket{A="B",C="D",le="0"} 0
-invalid_hist_name_bucket{A="B",C="D",le="5"} 0
-invalid_hist_name_bucket{A="B",C="D",le="10"} 0
-invalid_hist_name_bucket{A="B",C="D",le="25"} 1
-invalid_hist_name_bucket{A="B",C="D",le="50"} 1
-invalid_hist_name_bucket{A="B",C="D",le="75"} 1
-invalid_hist_name_bucket{A="B",C="D",le="100"} 1
-invalid_hist_name_bucket{A="B",C="D",le="250"} 1
-invalid_hist_name_bucket{A="B",C="D",le="500"} 1
-invalid_hist_name_bucket{A="B",C="D",le="750"} 1
-invalid_hist_name_bucket{A="B",C="D",le="1000"} 1
-invalid_hist_name_bucket{A="B",C="D",le="2500"} 1
-invalid_hist_name_bucket{A="B",C="D",le="5000"} 1
-invalid_hist_name_bucket{A="B",C="D",le="7500"} 1
-invalid_hist_name_bucket{A="B",C="D",le="10000"} 1
-invalid_hist_name_bucket{A="B",C="D",le="+Inf"} 1
-invalid_hist_name_sum{A="B",C="D"} 23
-invalid_hist_name_count{A="B",C="D"} 1
+invalid_hist_name_bucket{A="B",C="D",le="0",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 0
+invalid_hist_name_bucket{A="B",C="D",le="5",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 0
+invalid_hist_name_bucket{A="B",C="D",le="10",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 0
+invalid_hist_name_bucket{A="B",C="D",le="25",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="50",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="75",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="100",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="250",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="500",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="750",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="1000",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="2500",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="5000",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="7500",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="10000",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_bucket{A="B",C="D",le="+Inf",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+invalid_hist_name_sum{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 23
+invalid_hist_name_count{A="B",C="D",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1
 # HELP target_info Target metadata
 # TYPE target_info gauge
 target_info{service_name="prometheus_test",telemetry_sdk_language="go",telemetry_sdk_name="opentelemetry",telemetry_sdk_version="latest"} 1

exporters/prometheus/testdata/without_target_info.txt

@@ -1,3 +1,6 @@
 # HELP foo_total a simple counter
 # TYPE foo_total counter
-foo_total{A="B",C="D",E="true",F="42"} 24.3
+foo_total{A="B",C="D",E="true",F="42",otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 24.3
+# HELP otel_scope_info Instrumentation Scope metadata
+# TYPE otel_scope_info gauge
+otel_scope_info{otel_scope_name="testmeter",otel_scope_version="v0.1.0"} 1