metrics: Metrics to monitoring/v3.MetricDescriptor

A converter from Metrics to a monitoring/v3.MetricDescriptor Updates #64.
census-ecosystem · Dec 11, 2018 · ea69b46 · ea69b46
1 parent c719bc1
commit ea69b46
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Showing 3 changed files with 201 additions and 5 deletions.
diff --git a/metrics.go b/metrics.go
@@ -20,16 +20,91 @@ directly to Stackdriver Metrics.
 */
 
 import (
+	"errors"
 	"fmt"
+	"path"
 
 	"github.com/golang/protobuf/ptypes/timestamp"
 
 	distributionpb "google.golang.org/genproto/googleapis/api/distribution"
+	labelpb "google.golang.org/genproto/googleapis/api/label"
+	googlemetricpb "google.golang.org/genproto/googleapis/api/metric"
 	monitoringpb "google.golang.org/genproto/googleapis/monitoring/v3"
 
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
 )
 
+var errNilMetric = errors.New("expecting a non-nil metric")
+
+func (se *statsExporter) protoToMonitoringMetricDescriptor(metric *metricspb.Metric) (*googlemetricpb.MetricDescriptor, error) {
+	if metric == nil {
+		return nil, errNilMetric
+	}
+
+	metricName, description, unit, _ := metricProseFromProto(metric)
+	metricType, _ := se.metricTypeFromProto(metricName)
+	displayName := se.displayName(metricName)
+	metricKind, valueType := protoMetricDescriptorTypeToMetricKind(metric)
+
+	sdm := &googlemetricpb.MetricDescriptor{
+		Name:        fmt.Sprintf("projects/%s/metricDescriptors/%s", se.o.ProjectID, metricType),
+		DisplayName: displayName,
+		Description: description,
+		Unit:        unit,
+		Type:        metricType,
+		MetricKind:  metricKind,
+		ValueType:   valueType,
+		Labels:      labelDescriptorsFromProto(se.defaultLabels, metric.GetMetricDescriptor().GetLabelKeys()),
+	}
+
+	return sdm, nil
+}
+
+func labelDescriptorsFromProto(defaults map[string]labelValue, protoLabelKeys []*metricspb.LabelKey) []*labelpb.LabelDescriptor {
+	labelDescriptors := make([]*labelpb.LabelDescriptor, 0, len(defaults)+len(protoLabelKeys))
+
+	// Fill in the defaults first.
+	for key, lbl := range defaults {
+		labelDescriptors = append(labelDescriptors, &labelpb.LabelDescriptor{
+			Key:         sanitize(key),
+			Description: lbl.desc,
+			ValueType:   labelpb.LabelDescriptor_STRING,
+		})
+	}
+
+	// Now fill in those from the metric.
+	for _, protoKey := range protoLabelKeys {
+		labelDescriptors = append(labelDescriptors, &labelpb.LabelDescriptor{
+			Key:         sanitize(protoKey.GetKey()),
+			Description: protoKey.GetDescription(),
+			ValueType:   labelpb.LabelDescriptor_STRING, // We only use string tags
+		})
+	}
+	return labelDescriptors
+}
+
+func metricProseFromProto(metric *metricspb.Metric) (name, description, unit string, ok bool) {
+	mname := metric.GetName()
+	if mname != "" {
+		name = mname
+		return
+	}
+
+	md := metric.GetMetricDescriptor()
+
+	name = md.GetName()
+	unit = md.GetUnit()
+	description = md.GetDescription()
+
+	return
+}
+
+func (se *statsExporter) metricTypeFromProto(name string) (string, bool) {
+	// TODO: (@odeke-em) support non-"custom.googleapis.com" metrics names.
+	name = path.Join("custom.googleapis.com", "opencensus", name)
+	return name, true
+}
+
 func fromProtoPoint(startTime *timestamp.Timestamp, pt *metricspb.Point) (*monitoringpb.Point, error) {
 	if pt == nil {
 		return nil, nil
@@ -133,3 +208,33 @@ func bucketCounts(buckets []*metricspb.DistributionValue_Bucket) []int64 {
 	}
 	return bucketCounts
 }
+
+func protoMetricDescriptorTypeToMetricKind(m *metricspb.Metric) (googlemetricpb.MetricDescriptor_MetricKind, googlemetricpb.MetricDescriptor_ValueType) {
+	dt := m.GetMetricDescriptor()
+	if dt == nil {
+		return googlemetricpb.MetricDescriptor_METRIC_KIND_UNSPECIFIED, googlemetricpb.MetricDescriptor_VALUE_TYPE_UNSPECIFIED
+	}
+
+	switch dt.Type {
+	case metricspb.MetricDescriptor_CUMULATIVE_INT64:
+		return googlemetricpb.MetricDescriptor_CUMULATIVE, googlemetricpb.MetricDescriptor_INT64
+
+	case metricspb.MetricDescriptor_CUMULATIVE_DOUBLE:
+		return googlemetricpb.MetricDescriptor_CUMULATIVE, googlemetricpb.MetricDescriptor_DOUBLE
+
+	case metricspb.MetricDescriptor_CUMULATIVE_DISTRIBUTION:
+		return googlemetricpb.MetricDescriptor_CUMULATIVE, googlemetricpb.MetricDescriptor_DISTRIBUTION
+
+	case metricspb.MetricDescriptor_GAUGE_DOUBLE:
+		return googlemetricpb.MetricDescriptor_GAUGE, googlemetricpb.MetricDescriptor_DOUBLE
+
+	case metricspb.MetricDescriptor_GAUGE_INT64:
+		return googlemetricpb.MetricDescriptor_GAUGE, googlemetricpb.MetricDescriptor_INT64
+
+	case metricspb.MetricDescriptor_GAUGE_DISTRIBUTION:
+		return googlemetricpb.MetricDescriptor_GAUGE, googlemetricpb.MetricDescriptor_DISTRIBUTION
+
+	default:
+		return googlemetricpb.MetricDescriptor_METRIC_KIND_UNSPECIFIED, googlemetricpb.MetricDescriptor_VALUE_TYPE_UNSPECIFIED
+	}
+}
diff --git a/metrics_test.go b/metrics_test.go
@@ -17,15 +17,102 @@ package stackdriver
 import (
 	"encoding/json"
 	"reflect"
+	"strings"
 	"testing"
 
 	"github.com/golang/protobuf/ptypes/timestamp"
 	distributionpb "google.golang.org/genproto/googleapis/api/distribution"
+	googlemetricpb "google.golang.org/genproto/googleapis/api/metric"
 	monitoringpb "google.golang.org/genproto/googleapis/monitoring/v3"
 
 	metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
 )
 
+func TestProtoToMonitoringMetricDescriptor(t *testing.T) {
+	tests := []struct {
+		in      *metricspb.Metric
+		want    *googlemetricpb.MetricDescriptor
+		wantErr string
+
+		statsExporter *statsExporter
+	}{
+		{in: nil, wantErr: "non-nil metric"},
+		{
+			in: &metricspb.Metric{},
+			statsExporter: &statsExporter{
+				o: Options{ProjectID: "test"},
+			},
+			want: &googlemetricpb.MetricDescriptor{
+				Name:        "projects/test/metricDescriptors/custom.googleapis.com/opencensus",
+				Type:        "custom.googleapis.com/opencensus",
+				DisplayName: "OpenCensus",
+			},
+		},
+		{
+			in: &metricspb.Metric{
+				Descriptor_: &metricspb.Metric_Name{Name: "with_name"},
+			},
+			statsExporter: &statsExporter{
+				o: Options{ProjectID: "test"},
+			},
+			want: &googlemetricpb.MetricDescriptor{
+				Name:        "projects/test/metricDescriptors/custom.googleapis.com/opencensus/with_name",
+				Type:        "custom.googleapis.com/opencensus/with_name",
+				DisplayName: "OpenCensus/with_name",
+			},
+		},
+		{
+			in: &metricspb.Metric{
+				Descriptor_: &metricspb.Metric_MetricDescriptor{
+					MetricDescriptor: &metricspb.MetricDescriptor{
+						Name:        "with_metric_descriptor",
+						Description: "This is with metric descriptor",
+						Unit:        "By",
+					},
+				},
+			},
+			statsExporter: &statsExporter{
+				o: Options{ProjectID: "test"},
+			},
+			want: &googlemetricpb.MetricDescriptor{
+				Name:        "projects/test/metricDescriptors/custom.googleapis.com/opencensus/with_metric_descriptor",
+				Type:        "custom.googleapis.com/opencensus/with_metric_descriptor",
+				DisplayName: "OpenCensus/with_metric_descriptor",
+				Description: "This is with metric descriptor",
+				Unit:        "By",
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		se := tt.statsExporter
+		if se == nil {
+			se = new(statsExporter)
+		}
+		got, err := se.protoToMonitoringMetricDescriptor(tt.in)
+		if tt.wantErr != "" {
+			if err == nil || !strings.Contains(err.Error(), tt.wantErr) {
+				t.Errorf("#%d: \nGot %v\nWanted error substring %q", i, err, tt.wantErr)
+			}
+			continue
+		}
+
+		if err != nil {
+			t.Errorf("#%d: Unexpected error: %v", i, err)
+			continue
+		}
+
+		if !reflect.DeepEqual(got, tt.want) {
+			// Our saving grace is serialization equality since some
+			// unexported fields could be present in the various values.
+			gj, wj := serializeAsJSON(got), serializeAsJSON(tt.want)
+			if gj != wj {
+				t.Errorf("#%d: Unmatched JSON\nGot:\n\t%s\nWant:\n\t%s", i, gj, wj)
+			}
+		}
+	}
+}
+
 func TestProtoMetricsToMonitoringMetrics_fromProtoPoint(t *testing.T) {
 	startTimestamp := &timestamp.Timestamp{
 		Seconds: 1543160298,

diff --git a/stats.go b/stats.go
@@ -278,11 +278,7 @@ func (e *statsExporter) createMeasure(ctx context.Context, v *view.View) error {
 
 	var displayName string
 	if e.o.GetMetricDisplayName == nil {
-		displayNamePrefix := defaultDisplayNamePrefix
-		if e.o.MetricPrefix != "" {
-			displayNamePrefix = e.o.MetricPrefix
-		}
-		displayName = path.Join(displayNamePrefix, viewName)
+		displayName = e.displayName(viewName)
 	} else {
 		displayName = e.o.GetMetricDisplayName(v)
 	}
@@ -308,6 +304,14 @@ func (e *statsExporter) createMeasure(ctx context.Context, v *view.View) error {
 	return nil
 }
 
+func (e *statsExporter) displayName(suffix string) string {
+	displayNamePrefix := defaultDisplayNamePrefix
+	if e.o.MetricPrefix != "" {
+		displayNamePrefix = e.o.MetricPrefix
+	}
+	return path.Join(displayNamePrefix, suffix)
+}
+
 func newPoint(v *view.View, row *view.Row, start, end time.Time) *monitoringpb.Point {
 	switch v.Aggregation.Type {
 	case view.AggTypeLastValue: