[connector/datadog] Allow export to traces pipelines (open-telemetry#27846)

**Description:** <Describe what has changed.>
Allow datadogconnector export to traces pipelines

**Link to tracking Issue:** <Issue number if applicable>

**Testing:** <Describe what testing was performed and which tests were
added.>

**Documentation:** <Describe the documentation added.>

---------

Co-authored-by: Pablo Baeyens <[email protected]>

Author: 2 people

.chloggen/datadog-connector-traces.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: datadogconnector
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Allow datadogconnector to be used as a traces-to-traces connector
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [27846]
+
+# (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: []

connector/datadogconnector/README.md

@@ -15,6 +15,7 @@
 | [Exporter Pipeline Type] | [Receiver Pipeline Type] | [Stability Level] |
 | ------------------------ | ------------------------ | ----------------- |
 | traces | metrics | [beta] |
+| traces | traces | [beta] |
 
 [Exporter Pipeline Type]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/connector/README.md#exporter-pipeline-type
 [Receiver Pipeline Type]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/connector/README.md#receiver-pipeline-type
@@ -91,7 +92,7 @@ service:
      exporters: [datadog/connector]
 
    traces/2: # this pipeline uses sampling
-     receivers: [otlp]
+     receivers: [datadog/connector]
      processors: [batch, probabilistic_sampler]
      exporters: [datadog]
 

connector/datadogconnector/connector.go

@@ -18,7 +18,8 @@ import (
 
 // connectorImp is the schema for connector
 type connectorImp struct {
-	metricsConsumer consumer.Metrics // the next component in the pipeline to ingest data after connector
+	metricsConsumer consumer.Metrics // the next component in the pipeline to ingest metrics after connector
+	tracesConsumer  consumer.Traces  // the next component in the pipeline to ingest traces after connector
 	logger          *zap.Logger
 
 	// agent specifies the agent used to ingest traces and output APM Stats.
@@ -40,7 +41,7 @@ type connectorImp struct {
 var _ component.Component = (*connectorImp)(nil) // testing that the connectorImp properly implements the type Component interface
 
 // function to create a new connector
-func newConnector(logger *zap.Logger, _ component.Config, nextConsumer consumer.Metrics) (*connectorImp, error) {
+func newConnector(logger *zap.Logger, _ component.Config, metricsConsumer consumer.Metrics, tracesConsumer consumer.Traces) (*connectorImp, error) {
 	logger.Info("Building datadog connector")
 
 	in := make(chan *pb.StatsPayload, 100)
@@ -55,7 +56,8 @@ func newConnector(logger *zap.Logger, _ component.Config, nextConsumer consumer.
 		agent:           datadog.NewAgent(ctx, in),
 		translator:      trans,
 		in:              in,
-		metricsConsumer: nextConsumer,
+		metricsConsumer: metricsConsumer,
+		tracesConsumer:  tracesConsumer,
 		exit:            make(chan struct{}),
 	}, nil
 }
@@ -64,7 +66,9 @@ func newConnector(logger *zap.Logger, _ component.Config, nextConsumer consumer.
 func (c *connectorImp) Start(_ context.Context, _ component.Host) error {
 	c.logger.Info("Starting datadogconnector")
 	c.agent.Start()
-	go c.run()
+	if c.metricsConsumer != nil {
+		go c.run()
+	}
 	return nil
 }
 
@@ -85,6 +89,9 @@ func (c *connectorImp) Capabilities() consumer.Capabilities {
 
 func (c *connectorImp) ConsumeTraces(ctx context.Context, traces ptrace.Traces) error {
 	c.agent.Ingest(ctx, traces)
+	if c.tracesConsumer != nil {
+		return c.tracesConsumer.ConsumeTraces(ctx, traces)
+	}
 	return nil
 }
 

connector/datadogconnector/connector_test.go

@@ -23,9 +23,15 @@ func TestNewConnector(t *testing.T) {
 	creationParams := connectortest.NewNopCreateSettings()
 	cfg := factory.CreateDefaultConfig().(*Config)
 
-	traceConnector, err := factory.CreateTracesToMetrics(context.Background(), creationParams, cfg, consumertest.NewNop())
+	traceToMetricsConnector, err := factory.CreateTracesToMetrics(context.Background(), creationParams, cfg, consumertest.NewNop())
 	assert.NoError(t, err)
 
-	_, ok := traceConnector.(*connectorImp)
+	_, ok := traceToMetricsConnector.(*connectorImp)
+	assert.True(t, ok) // checks if the created connector implements the connectorImp struct
+
+	traceToTracesConnector, err := factory.CreateTracesToTraces(context.Background(), creationParams, cfg, consumertest.NewNop())
+	assert.NoError(t, err)
+
+	_, ok = traceToTracesConnector.(*connectorImp)
 	assert.True(t, ok) // checks if the created connector implements the connectorImp struct
 }

connector/datadogconnector/factory.go

@@ -21,7 +21,8 @@ func NewFactory() connector.Factory {
 	return connector.NewFactory(
 		metadata.Type,
 		createDefaultConfig,
-		connector.WithTracesToMetrics(createTracesToMetricsConnector, metadata.TracesToMetricsStability))
+		connector.WithTracesToMetrics(createTracesToMetricsConnector, metadata.TracesToMetricsStability),
+		connector.WithTracesToTraces(createTracesToTracesConnector, metadata.TracesToTracesStability))
 }
 
 var _ component.Config = (*Config)(nil)
@@ -35,7 +36,15 @@ func createDefaultConfig() component.Config {
 // defines the consumer type of the connector
 // we want to consume traces and export metrics therefore define nextConsumer as metrics, consumer is the next component in the pipeline
 func createTracesToMetricsConnector(_ context.Context, params connector.CreateSettings, cfg component.Config, nextConsumer consumer.Metrics) (connector.Traces, error) {
-	c, err := newConnector(params.Logger, cfg, nextConsumer)
+	c, err := newConnector(params.Logger, cfg, nextConsumer, nil)
+	if err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func createTracesToTracesConnector(_ context.Context, params connector.CreateSettings, cfg component.Config, nextConsumer consumer.Traces) (connector.Traces, error) {
+	c, err := newConnector(params.Logger, cfg, nil, nextConsumer)
 	if err != nil {
 		return nil, err
 	}

connector/datadogconnector/internal/metadata/generated_status.go

@@ -3,7 +3,7 @@ type: datadog
 status:
   class: connector
   stability:
-    beta: [traces_to_metrics]
+    beta: [traces_to_metrics, traces_to_traces]
   distributions: [contrib]
   codeowners:
     active: [mx-psi, gbbr, dineshg13]