Make metric-type configurable as a CLI parameter, remove metric attributes

Author: marcelbirkner

cmd/telemetrygen/internal/metrics/config.go

@@ -13,10 +13,14 @@ import (
 type Config struct {
 	common.Config
 	NumMetrics int
+	MetricType metricType
 }
 
 // Flags registers config flags.
 func (c *Config) Flags(fs *pflag.FlagSet) {
+	c.MetricType = metricTypeGauge
+
 	c.CommonFlags(fs)
+	fs.Var(&c.MetricType, "metric-type", "Metric type enum. must be one of 'gauge', 'sum', 'histogram' or 'all'")
 	fs.IntVar(&c.NumMetrics, "metrics", 1, "Number of metrics to generate in each worker (ignored if duration is provided)")
 }

cmd/telemetrygen/internal/metrics/metrics.go

@@ -28,6 +28,7 @@ func Start(cfg *Config) error {
 	if err != nil {
 		return err
 	}
+	logger.Info("starting the metrics generator with configuration", zap.Any("config", cfg))
 
 	grpcExpOpt := []otlpmetricgrpc.Option{
 		otlpmetricgrpc.WithEndpoint(cfg.Endpoint),
@@ -104,6 +105,7 @@ func Run(c *Config, exp sdkmetric.Exporter, logger *zap.Logger) error {
 		wg.Add(1)
 		w := worker{
 			numMetrics:     c.NumMetrics,
+			metricType:     c.MetricType,
 			limitPerSecond: limit,
 			totalDuration:  c.TotalDuration,
 			running:        running,

cmd/telemetrygen/internal/metrics/worker.go

@@ -9,7 +9,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"go.opentelemetry.io/otel/attribute"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	"go.opentelemetry.io/otel/sdk/resource"
@@ -19,6 +18,7 @@ import (
 
 type worker struct {
 	running        *atomic.Bool    // pointer to shared flag that indicates it's time to stop the test
+	metricType     metricType      // type of metric to generate
 	numMetrics     int             // how many metrics the worker has to generate (only when duration==0)
 	totalDuration  time.Duration   // how long to run the test for (overrides `numMetrics`)
 	limitPerSecond rate.Limit      // how many metrics per second to generate
@@ -31,63 +31,59 @@ func (w worker) simulateMetrics(res *resource.Resource, exporter sdkmetric.Expor
 	limiter := rate.NewLimiter(w.limitPerSecond, 1)
 
 	var i int64
-	value := 24.42
-	attrs := attribute.NewSet(attribute.KeyValue{
-		Key:   attribute.Key("status.code"),
-		Value: attribute.StringValue("STATUS_CODE_OK"),
-	})
-
 	for w.running.Load() {
-		rm := metricdata.ResourceMetrics{
-			Resource: res,
-			ScopeMetrics: []metricdata.ScopeMetrics{
-				{
-					Metrics: []metricdata.Metrics{
+		var metrics []metricdata.Metrics
+		if w.metricType == metricTypeGauge || w.metricType == metricTypeAll {
+			metrics = append(metrics, metricdata.Metrics{
+				Name: "gen.metric.gauge",
+				Data: metricdata.Gauge[int64]{
+					DataPoints: []metricdata.DataPoint[int64]{
 						{
-							Name: "gen.metric.gauge",
-							Data: metricdata.Gauge[int64]{
-								DataPoints: []metricdata.DataPoint[int64]{
-									{
-										Attributes: attrs,
-										Time:  time.Now(),
-										Value: i,
-									},
-								},
-							},
+							StartTime: time.Now(),
+							Time:      time.Now().Add(1 * time.Second),
+							Value:     i,
 						},
+					},
+				},
+			})
+		} else if w.metricType == metricTypeSum || w.metricType == metricTypeAll {
+			metrics = append(metrics, metricdata.Metrics{
+				Name: "gen.metric.sum",
+				Data: metricdata.Sum[int64]{
+					IsMonotonic: true,
+					Temporality: metricdata.DeltaTemporality,
+					DataPoints: []metricdata.DataPoint[int64]{
 						{
-							Name: "gen.metric.sum",
-							Data: metricdata.Sum[int64]{
-								IsMonotonic: true,
-								Temporality: metricdata.DeltaTemporality,
-								DataPoints: []metricdata.DataPoint[int64]{
-									{
-										Attributes: attrs,
-										StartTime:  time.Now(),
-										Time:       time.Now().Add(1 * time.Second),
-										Value:      i,
-									},
-								},
-							},
+							StartTime: time.Now(),
+							Time:      time.Now().Add(1 * time.Second),
+							Value:     i,
 						},
+					},
+				},
+			})
+		} else if w.metricType == metricTypeHistogram || w.metricType == metricTypeAll {
+			value := 24.42
+			metrics = append(metrics, metricdata.Metrics{
+				Name: "gen.metric.histogram",
+				Data: metricdata.Histogram[float64]{
+					Temporality: metricdata.CumulativeTemporality,
+					DataPoints: []metricdata.HistogramDataPoint[float64]{
 						{
-							Name: "gen.metric.histogram",
-							Data: metricdata.Histogram[float64]{
-								Temporality: metricdata.CumulativeTemporality,
-								DataPoints: []metricdata.HistogramDataPoint[float64]{
-									{
-										Attributes: attrs,
-										Sum:        float64(float32(value)),
-										Max:        metricdata.NewExtrema(float64(float32(value))),
-										Min:        metricdata.NewExtrema(float64(float32(value))),
-										Count:      1,
-									},
-								},
-							},
+							Sum:   float64(float32(value)),
+							Max:   metricdata.NewExtrema(float64(float32(value))),
+							Min:   metricdata.NewExtrema(float64(float32(value))),
+							Count: 1,
 						},
 					},
 				},
-			},
+			})
+		} else {
+			w.logger.Fatal("unknown metric type")
+		}
+
+		rm := metricdata.ResourceMetrics{
+			Resource:     res,
+			ScopeMetrics: []metricdata.ScopeMetrics{{Metrics: metrics}},
 		}
 
 		if err := exporter.Export(context.Background(), &rm); err != nil {