otlp ingest: metrics: add infra_tags_as_tags to promote custom tags

comp/otelcol/ddflareextension/impl/testdata/simple-dd/config-enhanced-result.yaml

@@ -122,6 +122,7 @@ processors:
     allow_hostname_override: false
     cardinality: 0
     logs_tags_as_ddtags: false
+    metrics_attributes_as_tags: false
     trace_container_tag_promotion: "off"
 receivers:
   otlp:

comp/otelcol/otlp/collector.go

@@ -151,6 +151,11 @@ type PipelineConfig struct {
 	// `ddtags` log record attribute (real Datadog log tags) instead of resource
 	// attributes (log attributes) for the Logs pipeline.
 	LogsTagsAsDDTags bool
+	// MetricsInfraAttrsAsTags controls whether the InfraAttributes processor promotes
+	// custom tags (e.g. from kubernetesResourcesLabelsAsTags/AnnotationsAsTags) so they
+	// survive the metrics translator's allowlist and become metric tags for the Metrics
+	// pipeline. Without it, custom tags that are not known DD/OTel conventions are dropped.
+	MetricsInfraAttrsAsTags bool
 	// Logs contains configuration options for the logs
 	Logs map[string]interface{}
 	// Debug contains debug configurations.

comp/otelcol/otlp/components/processor/infraattributesprocessor/config.go

@@ -73,6 +73,21 @@ type Config struct {
 	//
 	// This only affects the logs pipeline.
 	LogsTagsAsDDTags bool `mapstructure:"logs_tags_as_ddtags"`
+
+	// MetricsAttributesAsTags controls whether custom tags emitted by the tagger
+	// (e.g. via kubernetesResourcesLabelsAsTags / AnnotationsAsTags) are promoted
+	// so they survive the metrics translator's allowlist and become metric tags.
+	//
+	// The metrics translator (attributes.TagsFromAttributes) keeps only an
+	// allowlist of known DD / OTel convention keys and drops arbitrary keys. To
+	// get custom tags onto metrics, the processor writes them under the
+	// `datadog.container.tag.<key>` prefix that the translator promotes into metric
+	// tags (attributes.ContainerTagsFromResourceAttributes). When false (default),
+	// behavior is unchanged: custom tags remain plain resource attributes and are
+	// dropped by the allowlist.
+	//
+	// This only affects the metrics pipeline.
+	MetricsAttributesAsTags bool `mapstructure:"metrics_attributes_as_tags"`
 }
 
 var _ component.Config = (*Config)(nil)

comp/otelcol/otlp/components/processor/infraattributesprocessor/config.schema.yaml

@@ -14,3 +14,6 @@ properties:
   logs_tags_as_ddtags:
     description: 'LogsTagsAsDDTags controls whether custom tags emitted by the tagger (e.g. via kubernetesResourcesLabelsAsTags / AnnotationsAsTags) are written as a `ddtags` log record attribute -- which the Datadog logs intake turns into real log tags -- instead of as resource attributes, which surface as log attributes.'
     type: boolean
+  metrics_attributes_as_tags:
+    description: 'MetricsAttributesAsTags controls whether custom tags emitted by the tagger (e.g. via kubernetesResourcesLabelsAsTags / AnnotationsAsTags) are promoted so they survive the metrics translator''s allowlist and become metric tags.'
+    type: boolean

comp/otelcol/otlp/components/processor/infraattributesprocessor/metrics.go

@@ -37,16 +37,24 @@ func newInfraAttributesMetricProcessor(
 }
 
 func (iamp *infraAttributesMetricProcessor) processMetrics(_ context.Context, md pmetric.Metrics) (pmetric.Metrics, error) {
+	// When metrics_attributes_as_tags is enabled, promote custom tagger labels (e.g. from
+	// kubernetesResourcesLabelsAsTags) so they survive the metrics translator's
+	// allowlist. The metrics path consumes them via the `datadog.container.tag.`
+	// prefix: attributes.TagsFromAttributes (metrics_translator.go) calls
+	// attributes.ContainerTagsFromResourceAttributes, which extracts that prefix
+	// into metric tags. Without promotion, custom labels that are not known DD /
+	// OTel conventions are dropped from OTLP metrics (see OTELS-1131). "duplicate"
+	// keeps the original resource attribute and additionally writes the prefixed
+	// form the translator reads.
+	promote := ContainerTagPromotionOff
+	if iamp.cfg.MetricsAttributesAsTags {
+		promote = ContainerTagPromotionDuplicate
+	}
+
 	rms := md.ResourceMetrics()
 	for i := 0; i < rms.Len(); i++ {
 		resourceAttributes := rms.At(i).Resource().Attributes()
-		// trace_container_tag_promotion only makes sense for traces: it exists to
-		// feed trace-agent's `_dd.tags.container` promotion
-		// (ConsumeContainerTagsFromResource), which metrics never go through.
-		// The metrics path already recognizes DD-format keys directly via
-		// kubernetesDDTags, so prefixing would only strand data under
-		// `rename`. Always pass "off" here regardless of the configured mode.
-		iamp.infraTags.ProcessTags(iamp.logger, iamp.cardinality, resourceAttributes, iamp.cfg.AllowHostnameOverride, ContainerTagPromotionOff, false, nil)
+		iamp.infraTags.ProcessTags(iamp.logger, iamp.cardinality, resourceAttributes, iamp.cfg.AllowHostnameOverride, promote, false, nil)
 	}
 	return md, nil
 }

comp/otelcol/otlp/components/processor/infraattributesprocessor/metrics_test.go

@@ -275,6 +275,71 @@ func TestInfraAttributesMetricProcessorIgnoresContainerTagPromotion(t *testing.T
 	}
 }
 
+// TestInfraAttributesMetricProcessorMetricsAttributesAsTags verifies that a custom
+// tagger tag is promoted under the `datadog.container.tag.` prefix (so the
+// metrics translator keeps it as a metric tag) only when metrics_attributes_as_tags
+// is enabled. This is the OTELS-1131 fix.
+func TestInfraAttributesMetricProcessorMetricsAttributesAsTags(t *testing.T) {
+	tests := []struct {
+		name             string
+		attributesAsTags bool
+		expected         map[string]any
+	}{
+		{
+			name:             "disabled: custom tag dropped by translator (stays unprefixed)",
+			attributesAsTags: false,
+			expected: map[string]any{
+				"container.id": "test",
+				"test_tag":     "bar",
+			},
+		},
+		{
+			name:             "enabled: custom tag duplicated under prefixed key",
+			attributesAsTags: true,
+			expected: map[string]any{
+				"container.id":                   "test",
+				"test_tag":                       "bar",
+				"datadog.container.tag.test_tag": "bar",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			next := new(consumertest.MetricsSink)
+			cfg := &Config{
+				Cardinality:             types.LowCardinality,
+				MetricsAttributesAsTags: tt.attributesAsTags,
+			}
+			tc := testutil.NewTestTaggerClient()
+			tc.TagMap["container_id://test"] = []string{"test_tag:bar"}
+
+			factory := NewFactoryForAgent(tc, func(_ context.Context) (string, error) {
+				return "test-host", nil
+			})
+			fmp, err := factory.CreateMetrics(
+				context.Background(),
+				processortest.NewNopSettings(Type),
+				cfg,
+				next,
+			)
+			assert.NoError(t, err)
+			ctx := context.Background()
+			assert.NoError(t, fmp.Start(ctx, nil))
+
+			md := testResourceMetrics([]metricWithResource{{
+				metricNames:        inMetricNames,
+				resourceAttributes: map[string]any{"container.id": "test"},
+			}})
+			assert.NoError(t, fmp.ConsumeMetrics(ctx, md))
+			assert.NoError(t, fmp.Shutdown(ctx))
+
+			assert.Len(t, next.AllMetrics(), 1)
+			out := next.AllMetrics()[0].ResourceMetrics().At(0).Resource().Attributes().AsRaw()
+			assert.EqualValues(t, tt.expected, out)
+		})
+	}
+}
+
 func TestEntityIDsFromAttributes(t *testing.T) {
 	tests := []struct {
 		name      string

comp/otelcol/otlp/config.go

@@ -83,6 +83,7 @@ func FromAgentConfig(cfg config.Reader) (PipelineConfig, error) {
 	TracesInfraAttributesEnabled := cfg.GetBool(coreconfig.OTLPTracesInfraAttrEnabled)
 	tracesContainerTagPromotion := cfg.GetString(coreconfig.OTLPTracesInfraAttrContainerTagPromotion)
 	logsTagsAsDDTags := cfg.GetBool(coreconfig.OTLPLogsInfraAttrTagsAsDDTags)
+	metricsInfraAttrsAsTags := cfg.GetBool(coreconfig.OTLPMetricsInfraAttrAsTags)
 
 	if !metricsEnabled && !tracesEnabled && !logsEnabled {
 		errs = append(errs, errors.New("at least one OTLP signal needs to be enabled"))
@@ -129,6 +130,7 @@ func FromAgentConfig(cfg config.Reader) (PipelineConfig, error) {
 		TracesInfraAttributesEnabled: TracesInfraAttributesEnabled,
 		TracesContainerTagPromotion:  tracesContainerTagPromotion,
 		LogsTagsAsDDTags:             logsTagsAsDDTags,
+		MetricsInfraAttrsAsTags:      metricsInfraAttrsAsTags,
 		MetricsBatch:                 metricsBatchConfig.ToStringMap(),
 		Logs:                         logsConfig.ToStringMap(),
 		Debug:                        debugMap,

comp/otelcol/otlp/map_provider.go

@@ -69,6 +69,12 @@ func buildMetricsMap(cfg PipelineConfig) (*confmap.Conf, error) {
 		buildKey("exporters", "serializer", "metrics"):                cfg.Metrics,
 		buildKey("exporters", "serializer", "sending_queue", "batch"): ensureNonNilMap(cfg.MetricsBatch),
 	}
+	// The metrics pipeline shares the `infraattributes` processor instance with
+	// the logs pipeline (see defaultMetricsConfig/defaultLogsConfig); this is
+	// harmless since the logs processor ignores metrics_attributes_as_tags.
+	if cfg.MetricsInfraAttrsAsTags {
+		smap[buildKey("processors", "infraattributes", "metrics_attributes_as_tags")] = true
+	}
 	{
 		configMap := confmap.NewFromStringMap(smap)
 		err = baseMap.Merge(configMap)

comp/otelcol/otlp/map_provider_not_serverless_test.go

@@ -382,6 +382,69 @@ func TestNewMap(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "only metrics, metrics_attributes_as_tags on",
+			pcfg: PipelineConfig{
+				OTLPReceiverConfig:           testutil.OTLPConfigFromPorts("bindhost", 0, 1234),
+				TracePort:                    5003,
+				MetricsEnabled:               true,
+				TracesInfraAttributesEnabled: true,
+				TracesContainerTagPromotion:  "off",
+				MetricsInfraAttrsAsTags:      true,
+				Metrics: map[string]any{
+					"delta_ttl":                              1500,
+					"resource_attributes_as_tags":            false,
+					"instrumentation_scope_metadata_as_tags": false,
+					"histograms": map[string]any{
+						"mode":                   "nobuckets",
+						"send_count_sum_metrics": true,
+					},
+				},
+				Debug: map[string]any{
+					"verbosity": "none",
+				},
+			},
+			ocfg: map[string]any{
+				"receivers": map[string]any{
+					"otlp": map[string]any{
+						"protocols": map[string]any{
+							"http": map[string]any{
+								"endpoint": "bindhost:1234",
+							},
+						},
+					},
+				},
+				"processors": map[string]any{
+					"infraattributes": map[string]any{"metrics_attributes_as_tags": true},
+				},
+				"exporters": map[string]any{
+					"serializer": map[string]any{
+						"metrics": map[string]any{
+							"delta_ttl":                              1500,
+							"resource_attributes_as_tags":            false,
+							"instrumentation_scope_metadata_as_tags": false,
+							"histograms": map[string]any{
+								"mode":                   "nobuckets",
+								"send_count_sum_metrics": true,
+							},
+						},
+						"sending_queue": map[string]any{
+							"batch": map[string]any{},
+						},
+					},
+				},
+				"service": map[string]any{
+					"telemetry": map[string]any{"metrics": map[string]any{"level": "none"}},
+					"pipelines": map[string]any{
+						"metrics": map[string]any{
+							"receivers":  []any{"otlp"},
+							"processors": []any{"infraattributes"},
+							"exporters":  []any{"serializer"},
+						},
+					},
+				},
+			},
+		},
 		{
 			name: "only gRPC, only Traces, logging with normal verbosity",
 			pcfg: PipelineConfig{

pkg/config/schema/yaml/core_schema.yaml

@@ -4500,6 +4500,29 @@ properties:
             description: |-
               Set to false to disable metrics support in the OTLP ingest endpoint.
               To enable the OTLP ingest, the otlp_config.receiver section must be set.
+          infra_attributes:
+            node_type: section
+            type: object
+            visibility: public
+            description: Controls whether infrastructure attributes (host tags, container
+              tags) are attached to OTLP metrics ingested by the Agent.
+            tags:
+            - template_section:CoreAgent
+            properties:
+              as_tags:
+                node_type: setting
+                type: boolean
+                default: false
+                visibility: public
+                description: |-
+                  Controls whether the Infra-Attribute-Processor promotes custom tags (for example, from
+                  kubernetesResourcesLabelsAsTags/AnnotationsAsTags) so they survive the metrics translator's
+                  allowlist and are emitted as metric tags. Without it, custom tags that are not known Datadog
+                  or OpenTelemetry conventions are dropped.
+                comment: |-
+                  as_tags controls whether the infraattributes processor promotes custom tags
+                  (e.g. from kubernetesResourcesLabelsAsTags/AnnotationsAsTags) so they survive the metrics
+                  translator's allowlist and become metric tags.
           resource_attributes_as_tags:
             node_type: setting
             type: boolean

pkg/config/setup/otlp.go

@@ -20,9 +20,10 @@ const (
 	OTLPReceiverSubSectionKey = "receiver"
 	OTLPReceiverSection       = OTLPSection + "." + OTLPReceiverSubSectionKey
 
-	OTLPMetrics        = OTLPSection + ".metrics"
-	OTLPMetricsEnabled = OTLPMetrics + ".enabled"
-	OTLPMetricsBatch   = OTLPMetrics + ".batch"
+	OTLPMetrics                = OTLPSection + ".metrics"
+	OTLPMetricsEnabled         = OTLPMetrics + ".enabled"
+	OTLPMetricsBatch           = OTLPMetrics + ".batch"
+	OTLPMetricsInfraAttrAsTags = OTLPMetrics + ".infra_attributes.as_tags"
 
 	OTLPDebug = OTLPSection + "." + "debug"
 

releasenotes/notes/otlp-metrics-infra-tags-as-tags-7c0f6a1e2b9d4a83.yaml

@@ -0,0 +1,22 @@
+# Each section from every release note are combined when the
+# CHANGELOG.rst is rendered. So the text needs to be worded so that
+# it does not depend on any information only available in another
+# section. This may mean repeating some details, but each section
+# must be readable independently of the other.
+#
+# Each section note must be formatted as reStructuredText.
+---
+features:
+  - |
+    OTLP ingestion: Adds a new ``otlp_config.metrics.infra_attributes.as_tags`` option. When
+    enabled, custom tagger-derived tags (for example, tags configured via
+    ``kubernetesResourcesLabelsAsTags``/``kubernetesResourcesAnnotationsAsTags``) are promoted so they
+    survive the metrics translator's allowlist and are emitted as metric tags for OTLP metrics ingested
+    directly by the Agent. Without it, custom tags that are not known Datadog or OpenTelemetry
+    conventions are dropped. Default behavior is unchanged.
+  - |
+    DDOT: The ``infraattributes`` processor now supports a new ``metrics_attributes_as_tags`` option for the
+    metrics pipeline. When enabled, custom tagger-derived tags (for example, tags configured via
+    ``kubernetesResourcesLabelsAsTags``/``kubernetesResourcesAnnotationsAsTags``) are promoted so they
+    survive the metrics translator's allowlist and are emitted as metric tags. Default behavior is
+    unchanged.

test/new-e2e/tests/otel/otel-agent/testdata/minimal-full-config-datadogextension.yml

@@ -158,6 +158,7 @@ processors:
     allow_hostname_override: false
     cardinality: 0
     logs_tags_as_ddtags: false
+    metrics_attributes_as_tags: false
     trace_container_tag_promotion: "off"
   filter/drop-prometheus-internal-metrics/dd-autoconfigured:
     error_mode: ignore

test/new-e2e/tests/otel/otel-agent/testdata/minimal-full-config.yml

@@ -158,6 +158,7 @@ processors:
     allow_hostname_override: false
     cardinality: 0
     logs_tags_as_ddtags: false
+    metrics_attributes_as_tags: false
     trace_container_tag_promotion: "off"
   filter/drop-prometheus-internal-metrics/dd-autoconfigured:
     error_mode: ignore