Merge 1fa34984fa into 677efa4678

config/config.go

@@ -110,7 +110,7 @@ func Load(s string, logger *slog.Logger) (*Config, error) {
 	switch cfg.OTLPConfig.TranslationStrategy {
 	case UnderscoreEscapingWithSuffixes:
 	case "":
-	case NoUTF8EscapingWithSuffixes:
+	case NoTranslation, NoUTF8EscapingWithSuffixes:
 		if cfg.GlobalConfig.MetricNameValidationScheme == LegacyValidationConfig {
 			return nil, errors.New("OTLP translation strategy NoUTF8EscapingWithSuffixes is not allowed when UTF8 is disabled")
 		}
@@ -1436,6 +1436,15 @@ var (
 	// and label name characters that are not alphanumerics/underscores to underscores.
 	// Unit and type suffixes may be appended to metric names, according to certain rules.
 	UnderscoreEscapingWithSuffixes translationStrategyOption = "UnderscoreEscapingWithSuffixes"
+	// NoTranslation (EXPERIMENTAL): disables all translation of incoming metric
+	// and label names. Note that because metrics in Open Telemetry are considered
+	// distinct if they share the same name but have different Type or Units, for
+	// instance "foo.bar" with units Seconds is a separate series from "foo.bar"
+	// with units Milliseconds. Because prometheus does not yet support type and
+	// unit metadata, these two series would be conflated in Prometheus.
+	// Therefore this setting is experimental and should not be used in
+	// production systems.
+	NoTranslation translationStrategyOption = "NoTranslation"
 )
 
 // OTLPConfig is the configuration for writing to the OTLP endpoint.

config/config_test.go

@@ -1590,6 +1590,26 @@ func TestOTLPAllowUTF8(t *testing.T) {
 		})
 	})
 
+	t.Run("good config, no translation", func(t *testing.T) {
+		fpath := filepath.Join("testdata", "otlp_no_translation.good.yml")
+		verify := func(t *testing.T, conf *Config, err error) {
+			t.Helper()
+			require.NoError(t, err)
+			require.Equal(t, NoTranslation, conf.OTLPConfig.TranslationStrategy)
+		}
+
+		t.Run("LoadFile", func(t *testing.T) {
+			conf, err := LoadFile(fpath, false, promslog.NewNopLogger())
+			verify(t, conf, err)
+		})
+		t.Run("Load", func(t *testing.T) {
+			content, err := os.ReadFile(fpath)
+			require.NoError(t, err)
+			conf, err := Load(string(content), promslog.NewNopLogger())
+			verify(t, conf, err)
+		})
+	})
+
 	t.Run("incompatible config", func(t *testing.T) {
 		fpath := filepath.Join("testdata", "otlp_allow_utf8.incompatible.yml")
 		verify := func(t *testing.T, err error) {

config/testdata/otlp_no_translation.good.yml

@@ -0,0 +1,2 @@
+otlp:
+  translation_strategy: NoTranslation

storage/remote/write_handler.go

@@ -577,8 +577,8 @@ func (rw *rwExporter) ConsumeMetrics(ctx context.Context, md pmetric.Metrics) er
 
 	converter := otlptranslator.NewPrometheusConverter()
 	annots, err := converter.FromMetrics(ctx, md, otlptranslator.Settings{
-		AddMetricSuffixes:                 true,
-		AllowUTF8:                         otlpCfg.TranslationStrategy == config.NoUTF8EscapingWithSuffixes,
+		AddMetricSuffixes:                 otlpCfg.TranslationStrategy != config.NoTranslation,
+		AllowUTF8:                         otlpCfg.TranslationStrategy != config.UnderscoreEscapingWithSuffixes,
 		PromoteResourceAttributes:         otlpCfg.PromoteResourceAttributes,
 		KeepIdentifyingResourceAttributes: otlpCfg.KeepIdentifyingResourceAttributes,
 	})

storage/remote/write_handler_test.go

@@ -844,6 +844,19 @@ func requireEqual(t *testing.T, expected, actual interface{}, msgAndArgs ...inte
 		msgAndArgs...)
 }
 
+func requireContainsSample(t *testing.T, actual []mockSample, expected mockSample) {
+	t.Helper()
+
+	for _, got := range actual {
+		if labels.Equal(expected.l, got.l) && expected.t == got.t && expected.v == got.v {
+			return
+		}
+	}
+	require.Fail(t, fmt.Sprintf("Sample not found: \n"+
+		"expected: %v\n"+
+		"actual  : %v", expected, actual))
+}
+
 func (m *mockAppendable) Appender(_ context.Context) storage.Appender {
 	if m.latestSample == nil {
 		m.latestSample = map[uint64]int64{}

storage/remote/write_test.go

@@ -382,7 +382,44 @@ func TestWriteStorageApplyConfig_PartialUpdate(t *testing.T) {
 
 func TestOTLPWriteHandler(t *testing.T) {
 	exportRequest := generateOTLPWriteRequest()
+	resp, appendable := handleOtlp(t, exportRequest)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
 
+	require.Len(t, appendable.samples, 12)   // 1 (counter) + 1 (gauge) + 1 (target_info) + 7 (hist_bucket) + 2 (hist_sum, hist_count)
+	require.Len(t, appendable.histograms, 1) // 1 (exponential histogram)
+	require.Len(t, appendable.exemplars, 1)  // 1 (exemplar)
+}
+
+func TestOTLPWriteHandlerNoTranslation(t *testing.T) {
+	timestamp := time.Now()
+	exportRequest := generateCounterOTLPWriteRequest(timestamp)
+	resp, appendable := handleOtlp(t, exportRequest)
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	requireContainsSample(t, appendable.samples, mockSample{
+		l: labels.New(
+			labels.Label{Name: "__name__", Value: "test.counter"},
+			labels.Label{Name: "foo.bar", Value: "baz"},
+			labels.Label{Name: "instance", Value: "test-instance"},
+			labels.Label{Name: "job", Value: "test-service"},
+		),
+		t: timestamp.UnixMilli(),
+		v: 10,
+	})
+
+	requireContainsSample(t, appendable.samples, mockSample{
+		l: labels.New(
+			labels.Label{Name: "__name__", Value: "target_info"},
+			labels.Label{Name: "host.name", Value: "test-host"},
+			labels.Label{Name: "instance", Value: "test-instance"},
+			labels.Label{Name: "job", Value: "test-service"},
+		),
+		t: timestamp.UnixMilli(),
+		v: 1,
+	})
+}
+
+func handleOtlp(t *testing.T, exportRequest pmetricotlp.ExportRequest) (*http.Response, *mockAppendable) {
 	buf, err := exportRequest.MarshalProto()
 	require.NoError(t, err)
 
@@ -391,9 +428,11 @@ func TestOTLPWriteHandler(t *testing.T) {
 	req.Header.Set("Content-Type", "application/x-protobuf")
 
 	appendable := &mockAppendable{}
+	conf := config.DefaultOTLPConfig
+	conf.TranslationStrategy = config.NoTranslation
 	handler := NewOTLPWriteHandler(nil, nil, appendable, func() config.Config {
 		return config.Config{
-			OTLPConfig: config.DefaultOTLPConfig,
+			OTLPConfig: conf,
 		}
 	}, OTLPOptions{})
 
@@ -401,11 +440,39 @@ func TestOTLPWriteHandler(t *testing.T) {
 	handler.ServeHTTP(recorder, req)
 
 	resp := recorder.Result()
-	require.Equal(t, http.StatusOK, resp.StatusCode)
+	return resp, appendable
+}
 
-	require.Len(t, appendable.samples, 12)   // 1 (counter) + 1 (gauge) + 1 (target_info) + 7 (hist_bucket) + 2 (hist_sum, hist_count)
-	require.Len(t, appendable.histograms, 1) // 1 (exponential histogram)
-	require.Len(t, appendable.exemplars, 1)  // 1 (exemplar)
+func generateCounterOTLPWriteRequest(timestamp time.Time) pmetricotlp.ExportRequest {
+	d := pmetric.NewMetrics()
+
+	resourceMetric := d.ResourceMetrics().AppendEmpty()
+	resourceMetric.Resource().Attributes().PutStr("service.name", "test-service")
+	resourceMetric.Resource().Attributes().PutStr("service.instance.id", "test-instance")
+	resourceMetric.Resource().Attributes().PutStr("host.name", "test-host")
+
+	scopeMetric := resourceMetric.ScopeMetrics().AppendEmpty()
+
+	counterMetric := scopeMetric.Metrics().AppendEmpty()
+	counterMetric.SetName("test.counter")
+	counterMetric.SetDescription("test-counter-description")
+	counterMetric.SetEmptySum()
+	counterMetric.Sum().SetAggregationTemporality(pmetric.AggregationTemporalityCumulative)
+	counterMetric.Sum().SetIsMonotonic(true)
+
+	counterDataPoint := counterMetric.Sum().DataPoints().AppendEmpty()
+	counterDataPoint.SetTimestamp(pcommon.NewTimestampFromTime(timestamp))
+	counterDataPoint.SetDoubleValue(10.0)
+	counterDataPoint.Attributes().PutStr("foo.bar", "baz")
+
+	counterExemplar := counterDataPoint.Exemplars().AppendEmpty()
+
+	counterExemplar.SetTimestamp(pcommon.NewTimestampFromTime(timestamp))
+	counterExemplar.SetDoubleValue(10.0)
+	counterExemplar.SetSpanID(pcommon.SpanID{0, 1, 2, 3, 4, 5, 6, 7})
+	counterExemplar.SetTraceID(pcommon.TraceID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15})
+
+	return pmetricotlp.NewExportRequestFromMetrics(d)
 }
 
 func generateOTLPWriteRequest() pmetricotlp.ExportRequest {
@@ -426,7 +493,7 @@ func generateOTLPWriteRequest() pmetricotlp.ExportRequest {
 
 	// Generate One Counter
 	counterMetric := scopeMetric.Metrics().AppendEmpty()
-	counterMetric.SetName("test-counter")
+	counterMetric.SetName("test.counter")
 	counterMetric.SetDescription("test-counter-description")
 	counterMetric.SetEmptySum()
 	counterMetric.Sum().SetAggregationTemporality(pmetric.AggregationTemporalityCumulative)