Enable debug exporter when debug section is configured

Signed-off-by: Stanley Liu <stanley.liu@datadoghq.com>

Author: liustanley

comp/otelcol/otlp/collector.go

@@ -161,11 +161,12 @@ type PipelineConfig struct {
 	MetricsBatch map[string]interface{}
 }
 
-// shouldSetLoggingSection reports whether the debug exporter should be attached
-// to the OTLP ingest pipelines. It is enabled only when the user explicitly sets
-// otlp_config.debug.verbosity to a valid value other than "none". When verbosity
-// is unset, the debug exporter is not attached, so no per-batch debug logs are
-// emitted by default.
+// shouldSetLoggingSection reports whether the debug exporter should be attached to
+// the OTLP ingest pipelines. FromAgentConfig populates Debug["verbosity"] whenever the
+// user configures the otlp_config.debug section (defaulting it when the section is
+// declared without a verbosity), so a missing verbosity here means the section was not
+// configured and the exporter is not attached. An explicit "none" also leaves it
+// detached. As a result, no per-batch debug logs are emitted unless the user opts in.
 func (p *PipelineConfig) shouldSetLoggingSection() bool {
 	v, ok := p.Debug["verbosity"]
 	if !ok {

comp/otelcol/otlp/config.go

@@ -109,6 +109,15 @@ func FromAgentConfig(cfg config.Reader) (PipelineConfig, error) {
 	}
 
 	debugConfig := configcheck.ReadConfigSection(cfg, coreconfig.OTLPDebug)
+	debugMap := debugConfig.ToStringMap()
+	// If the user explicitly declares the otlp_config.debug section but does not set a
+	// verbosity, attach the debug exporter using the default verbosity. When the section
+	// is absent entirely, verbosity is left unset so the debug exporter is not attached.
+	if _, ok := debugMap["verbosity"]; !ok {
+		if cfg.HasSection(coreconfig.OTLPDebug) || cfg.IsConfigured(coreconfig.OTLPDebug) {
+			debugMap["verbosity"] = cfg.GetString(coreconfig.OTLPDebug + ".verbosity")
+		}
+	}
 
 	return PipelineConfig{
 		OTLPReceiverConfig:           otlpReceiverConfigMap,
@@ -122,7 +131,7 @@ func FromAgentConfig(cfg config.Reader) (PipelineConfig, error) {
 		LogsTagsAsDDTags:             logsTagsAsDDTags,
 		MetricsBatch:                 metricsBatchConfig.ToStringMap(),
 		Logs:                         logsConfig.ToStringMap(),
-		Debug:                        debugConfig.ToStringMap(),
+		Debug:                        debugMap,
 	}, multierr.Combine(errs...)
 }
 

comp/otelcol/otlp/config_test.go

@@ -729,9 +729,9 @@ func TestFromAgentConfigDebug(t *testing.T) {
 		err       string
 	}{
 		{
-			// A debug section with no verbosity does not enable the debug exporter:
-			// only an explicit non-"none" verbosity attaches it.
-			path:      "debug/empty_but_set_debug.yaml",
+			// A fully absent debug section leaves the exporter detached: verbosity is
+			// never populated, so no per-batch debug logs are emitted by default.
+			path:      "debug/absent_debug.yaml",
 			shouldSet: false,
 			cfg: PipelineConfig{
 				OTLPReceiverConfig:           map[string]interface{}{},
@@ -752,6 +752,31 @@ func TestFromAgentConfigDebug(t *testing.T) {
 				MetricsBatch: map[string]interface{}{},
 			},
 		},
+		{
+			// Explicitly declaring the debug section without a verbosity attaches the
+			// debug exporter using the default verbosity ("basic"). Only a fully absent
+			// debug section or an explicit "none" leaves the exporter detached.
+			path:      "debug/empty_but_set_debug.yaml",
+			shouldSet: true,
+			cfg: PipelineConfig{
+				OTLPReceiverConfig:           map[string]interface{}{},
+				TracePort:                    5003,
+				MetricsEnabled:               true,
+				TracesEnabled:                true,
+				LogsEnabled:                  false,
+				TracesInfraAttributesEnabled: true,
+				TracesContainerTagPromotion:  "off",
+				Logs:                         map[string]interface{}{},
+				Debug:                        map[string]interface{}{"verbosity": "basic"},
+				Metrics: map[string]interface{}{
+					"enabled":                                true,
+					"tag_cardinality":                        "low",
+					"apm_stats_receiver_addr":                "http://localhost:8126/v0.6/stats",
+					"instrumentation_scope_metadata_as_tags": true,
+				},
+				MetricsBatch: map[string]interface{}{},
+			},
+		},
 		{
 			path:      "debug/verbosity_detailed.yaml",
 			shouldSet: true,

comp/otelcol/otlp/testdata/debug/absent_debug.yaml

@@ -0,0 +1 @@
+otlp_config:

pkg/config/schema/yaml/core_schema.yaml

@@ -5928,6 +5928,9 @@ properties:
           This template lists the most commonly used settings; see the OpenTelemetry Collector documentation
           for a full list of available settings:
           https://github.com/open-telemetry/opentelemetry-collector/tree/main/exporter/debugexporter#getting-started
+          The debugexporter is off by default; it is attached only when this debug section
+          is configured. Declaring the section (even empty) enables it with the default
+          verbosity; set verbosity to none to leave it detached.
         tags:
         - template_section:CoreAgent
         properties:
@@ -5939,8 +5942,8 @@ properties:
             description: |-
               Verbosity of debug logs when Datadog Agent receives otlp traces/metrics.
               Valid values are basic, normal, detailed, none.
-              The debugexporter is off unless this is explicitly set; when unset,
-              no per-batch debug logs are emitted.
+              This default applies only once the debug section is configured; set it to
+              none to keep the debugexporter detached even when the section is present.
             comment: Debug settings (default from OTel debugexporter)
       grpc_port:
         node_type: setting

releasenotes/notes/otlp-ingest-debug-exporter-default-off-3f6c1a9b7e2d4c85.yaml

@@ -3,5 +3,8 @@ fixes:
   - |
     Agent OTLP Ingest no longer attaches the OpenTelemetry
     ``debugexporter`` by default. The ``debugexporter`` is now attached only when
-    ``otlp_config.debug.verbosity`` (or ``DD_OTLP_CONFIG_DEBUG_VERBOSITY``) is
-    explicitly set to ``basic``, ``normal``, or ``detailed``.
+    the ``otlp_config.debug`` section is explicitly configured. Declaring the
+    section without a verbosity uses the default verbosity (``basic``), while
+    setting ``otlp_config.debug.verbosity`` (or ``DD_OTLP_CONFIG_DEBUG_VERBOSITY``)
+    to ``basic``, ``normal``, or ``detailed`` selects the verbosity. Setting it to
+    ``none`` leaves the exporter detached.