feat: prom translation rw2 add support for labels (#35751)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
Adding full support for handling labels.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue #33661
Fixes

<!--Describe what testing was performed and which tests were added.-->
#### Testing

<!--Describe the documentation added.-->
#### Documentation

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---------

Signed-off-by: Juraj Michalek <[email protected]>
Co-authored-by: Arthur Silva Sens <[email protected]>
Co-authored-by: David Ashpole <[email protected]>

.chloggen/jm-prom-translation-rw2-add-support-for-labels.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/translator/prometheusremotewrite
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "`FromMetricsV2` now transforms attributes into labels."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [33661]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

pkg/translator/prometheusremotewrite/metrics_to_prw_v2.go

@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/prompb"
 	writev2 "github.com/prometheus/prometheus/prompb/io/prometheus/write/v2"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/pmetric"
@@ -49,6 +49,7 @@ func (c *prometheusConverterV2) fromMetrics(md pmetric.Metrics, settings Setting
 	resourceMetricsSlice := md.ResourceMetrics()
 	for i := 0; i < resourceMetricsSlice.Len(); i++ {
 		resourceMetrics := resourceMetricsSlice.At(i)
+		resource := resourceMetrics.Resource()
 		scopeMetricsSlice := resourceMetrics.ScopeMetrics()
 		// keep track of the most recent timestamp in the ResourceMetrics for
 		// use with the "target" info metric
@@ -77,7 +78,7 @@ func (c *prometheusConverterV2) fromMetrics(md pmetric.Metrics, settings Setting
 						errs = multierr.Append(errs, fmt.Errorf("empty data points. %s is dropped", metric.Name()))
 						break
 					}
-					c.addGaugeNumberDataPoints(dataPoints, promName)
+					c.addGaugeNumberDataPoints(dataPoints, resource, settings, promName)
 				case pmetric.MetricTypeSum:
 					// TODO implement
 				case pmetric.MetricTypeHistogram:
@@ -107,16 +108,25 @@ func (c *prometheusConverterV2) timeSeries() []writev2.TimeSeries {
 	return allTS
 }
 
-func (c *prometheusConverterV2) addSample(sample *writev2.Sample, lbls labels.Labels) *writev2.TimeSeries {
+func (c *prometheusConverterV2) addSample(sample *writev2.Sample, lbls []prompb.Label) *writev2.TimeSeries {
 	if sample == nil || len(lbls) == 0 {
 		// This shouldn't happen
 		return nil
 	}
-	ts := &writev2.TimeSeries{}
-	ts.LabelsRefs = c.symbolTable.SymbolizeLabels(lbls, ts.LabelsRefs)
-	ts.Samples = append(ts.Samples, *sample)
 
-	c.unique[lbls.Hash()] = ts
+	buf := make([]uint32, 0, len(lbls)*2)
+	var off uint32
+	for _, l := range lbls {
+		off = c.symbolTable.Symbolize(l.Name)
+		buf = append(buf, off)
+		off = c.symbolTable.Symbolize(l.Value)
+		buf = append(buf, off)
+	}
+	ts := writev2.TimeSeries{
+		LabelsRefs: buf,
+		Samples:    []writev2.Sample{*sample},
+	}
+	c.unique[timeSeriesSignature(lbls)] = &ts
 
-	return ts
+	return &ts
 }

pkg/translator/prometheusremotewrite/metrics_to_prw_v2_test.go

@@ -27,18 +27,16 @@ func TestFromMetricsV2(t *testing.T) {
 	want := func() map[string]*writev2.TimeSeries {
 		return map[string]*writev2.TimeSeries{
 			"0": {
-				LabelsRefs: []uint32{1, 2},
+				LabelsRefs: []uint32{1, 2, 3, 4, 5, 6, 7, 8},
 				Samples: []writev2.Sample{
 					{Timestamp: convertTimeStamp(pcommon.Timestamp(ts)), Value: 1.23},
 				},
 			},
 		}
 	}
+	wantedSymbols := []string{"", "series_name_2", "value-2", "series_name_3", "value-3", "__name__", "gauge_1", "series_name_1", "value-1"}
 	tsMap, symbolsTable, err := FromMetricsV2(payload.Metrics(), settings)
-	wanted := want()
 	require.NoError(t, err)
-	require.NotNil(t, tsMap)
-	require.Equal(t, wanted, tsMap)
-	require.NotNil(t, symbolsTable)
-
+	require.Equal(t, want(), tsMap)
+	require.ElementsMatch(t, wantedSymbols, symbolsTable.Symbols())
 }

pkg/translator/prometheusremotewrite/number_data_points_v2.go

@@ -7,23 +7,26 @@ import (
 	"math"
 
 	"github.com/prometheus/common/model"
-	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/model/value"
 	writev2 "github.com/prometheus/prometheus/prompb/io/prometheus/write/v2"
+	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 )
 
-func (c *prometheusConverterV2) addGaugeNumberDataPoints(dataPoints pmetric.NumberDataPointSlice, name string) {
+func (c *prometheusConverterV2) addGaugeNumberDataPoints(dataPoints pmetric.NumberDataPointSlice,
+	resource pcommon.Resource, settings Settings, name string) {
 	for x := 0; x < dataPoints.Len(); x++ {
 		pt := dataPoints.At(x)
-		// TODO implement support for labels
 
-		labels := labels.Labels{
-			labels.Label{
-				Name:  model.MetricNameLabel,
-				Value: name,
-			},
-		}
+		labels := createAttributes(
+			resource,
+			pt.Attributes(),
+			settings.ExternalLabels,
+			nil,
+			true,
+			model.MetricNameLabel,
+			name,
+		)
 
 		sample := &writev2.Sample{
 			// convert ns to ms

pkg/translator/prometheusremotewrite/number_data_points_v2_test.go

@@ -108,8 +108,16 @@ func TestPrometheusConverterV2_addGaugeNumberDataPoints(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			metric := tt.metric()
+			settings := Settings{
+				Namespace:           "",
+				ExternalLabels:      nil,
+				DisableTargetInfo:   false,
+				ExportCreatedMetric: false,
+				AddMetricSuffixes:   false,
+				SendMetadata:        false,
+			}
 			converter := newPrometheusConverterV2()
-			converter.addGaugeNumberDataPoints(metric.Gauge().DataPoints(), metric.Name())
+			converter.addGaugeNumberDataPoints(metric.Gauge().DataPoints(), pcommon.NewResource(), settings, metric.Name())
 			w := tt.want()
 
 			diff := cmp.Diff(w, converter.unique, cmpopts.EquateNaNs())
@@ -150,9 +158,18 @@ func TestPrometheusConverterV2_addGaugeNumberDataPointsDuplicate(t *testing.T) {
 		}
 	}
 
+	settings := Settings{
+		Namespace:           "",
+		ExternalLabels:      nil,
+		DisableTargetInfo:   false,
+		ExportCreatedMetric: false,
+		AddMetricSuffixes:   false,
+		SendMetadata:        false,
+	}
+
 	converter := newPrometheusConverterV2()
-	converter.addGaugeNumberDataPoints(metric1.Gauge().DataPoints(), metric1.Name())
-	converter.addGaugeNumberDataPoints(metric2.Gauge().DataPoints(), metric2.Name())
+	converter.addGaugeNumberDataPoints(metric1.Gauge().DataPoints(), pcommon.NewResource(), settings, metric1.Name())
+	converter.addGaugeNumberDataPoints(metric2.Gauge().DataPoints(), pcommon.NewResource(), settings, metric2.Name())
 
 	assert.Equal(t, want(), converter.unique)