feat: informative user-agent for otlp exporters

config/confighttp/confighttp.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/rs/cors"
@@ -119,6 +120,22 @@ func (hcs *HTTPClientSettings) ToClient(ext map[config.ComponentID]component.Ext
 	}, nil
 }
 
+// WithDefaultUserAgent adds a user-agent header to settings, unless one already exists.
+func (hcs *HTTPClientSettings) WithDefaultUserAgent(defaultUserAgent string) {
+	userAgentFound := false
+	for k := range hcs.Headers {
+		if strings.ToLower(k) == "user-agent" {
+			userAgentFound = true
+		}
+	}
+	if !userAgentFound {
+		if hcs.Headers == nil {
+			hcs.Headers = map[string]string{}
+		}
+		hcs.Headers["User-Agent"] = defaultUserAgent
+	}
+}
+
 // Custom RoundTripper that adds headers.
 type headerRoundTripper struct {
 	transport http.RoundTripper

config/confighttp/confighttp_test.go

@@ -560,22 +560,45 @@ func ExampleHTTPServerSettings() {
 
 func TestHttpHeaders(t *testing.T) {
 	tests := []struct {
-		name    string
-		headers map[string]string
+		name       string
+		headers    map[string]string
+		defaultUA  string
+		expectedUA string
 	}{
 		{
-			"with_headers",
-			map[string]string{
+			name: "with_headers_no_user_agent",
+			headers: map[string]string{
 				"header1": "value1",
 			},
 		},
+		{
+			name: "with_custom_user_agent",
+			headers: map[string]string{
+				"header1":    "value1",
+				"User-Agent": "My Test Agent",
+			},
+			defaultUA:  "Collector/1.2.3test",
+			expectedUA: "My Test Agent",
+		},
+		{
+			name: "with_custom_user_agent_lowercase",
+			headers: map[string]string{
+				"header1":    "value1",
+				"user-agent": "My Test Agent",
+			},
+			defaultUA:  "Collector/1.2.3test",
+			expectedUA: "My Test Agent",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				for k, v := range tt.headers {
 					assert.Equal(t, r.Header.Get(k), v)
 				}
+				if tt.expectedUA != "" {
+					assert.Equal(t, tt.expectedUA, r.Header.Get("user-agent"))
+				}
 				w.WriteHeader(200)
 			}))
 			defer server.Close()
@@ -586,9 +609,10 @@ func TestHttpHeaders(t *testing.T) {
 				ReadBufferSize:  0,
 				WriteBufferSize: 0,
 				Timeout:         0,
-				Headers: map[string]string{
-					"header1": "value1",
-				},
+				Headers:         tt.headers,
+			}
+			if tt.defaultUA != "" {
+				setting.WithDefaultUserAgent(tt.defaultUA)
 			}
 			client, _ := setting.ToClient(map[config.ComponentID]component.Extension{})
 			req, err := http.NewRequest("GET", setting.Endpoint, nil)

exporter/exporterhelper/common.go

@@ -16,6 +16,8 @@ package exporterhelper
 
 import (
 	"context"
+	"fmt"
+	"runtime"
 	"time"
 
 	"go.opentelemetry.io/collector/component"
@@ -237,3 +239,8 @@ func (ts *timeoutSender) send(req request) error {
 	}
 	return req.export(ctx)
 }
+
+// DefaultUserAgent User-Agent value used by exporters
+func DefaultUserAgent(info component.BuildInfo) string {
+	return fmt.Sprintf("%s/%s (%s/%s)", info.Description, info.Version, runtime.GOOS, runtime.GOARCH)
+}

exporter/otlpexporter/factory.go

@@ -58,7 +58,7 @@ func createTracesExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.TracesExporter, error) {
-	oce, err := newExporter(cfg)
+	oce, err := newExporter(cfg, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -80,7 +80,7 @@ func createMetricsExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.MetricsExporter, error) {
-	oce, err := newExporter(cfg)
+	oce, err := newExporter(cfg, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -103,7 +103,7 @@ func createLogsExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.LogsExporter, error) {
-	oce, err := newExporter(cfg)
+	oce, err := newExporter(cfg, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}

exporter/otlpexporter/otlp.go

@@ -36,26 +36,27 @@ import (
 
 type exporter struct {
 	// Input configuration.
-	config *Config
-	w      *grpcSender
+	config    *Config
+	w         *grpcSender
+	buildInfo component.BuildInfo
 }
 
 // Crete new exporter and start it. The exporter will begin connecting but
 // this function may return before the connection is established.
-func newExporter(cfg config.Exporter) (*exporter, error) {
+func newExporter(cfg config.Exporter, buildInfo component.BuildInfo) (*exporter, error) {
 	oCfg := cfg.(*Config)
 
 	if oCfg.Endpoint == "" {
 		return nil, errors.New("OTLP exporter config requires an Endpoint")
 	}
 
-	return &exporter{config: oCfg}, nil
+	return &exporter{config: oCfg, buildInfo: buildInfo}, nil
 }
 
 // start actually creates the gRPC connection. The client construction is deferred till this point as this
 // is the only place we get hold of Extensions which are required to construct auth round tripper.
 func (e *exporter) start(_ context.Context, host component.Host) (err error) {
-	e.w, err = newGrpcSender(e.config, host)
+	e.w, err = newGrpcSender(e.config, host, e.buildInfo)
 	return
 }
 
@@ -94,11 +95,12 @@ type grpcSender struct {
 	callOptions    []grpc.CallOption
 }
 
-func newGrpcSender(config *Config, host component.Host) (*grpcSender, error) {
+func newGrpcSender(config *Config, host component.Host, info component.BuildInfo) (*grpcSender, error) {
 	dialOpts, err := config.GRPCClientSettings.ToDialOptions(host)
 	if err != nil {
 		return nil, err
 	}
+	dialOpts = append(dialOpts, grpc.WithUserAgent(exporterhelper.DefaultUserAgent(info)))
 
 	var clientConn *grpc.ClientConn
 	if clientConn, err = grpc.Dial(config.GRPCClientSettings.SanitizedEndpoint(), dialOpts...); err != nil {

exporter/otlpexporter/otlp_test.go

@@ -203,6 +203,8 @@ func TestSendTraces(t *testing.T) {
 		},
 	}
 	set := componenttest.NewNopExporterCreateSettings()
+	set.BuildInfo.Description = "Collector"
+	set.BuildInfo.Version = "1.2.3test"
 	exp, err := factory.CreateTracesExporter(context.Background(), set, cfg)
 	require.NoError(t, err)
 	require.NotNil(t, exp)
@@ -247,7 +249,10 @@ func TestSendTraces(t *testing.T) {
 	assert.EqualValues(t, 2, atomic.LoadInt32(&rcv.requestCount))
 	assert.EqualValues(t, td, rcv.GetLastRequest())
 
-	require.EqualValues(t, rcv.GetMetadata().Get("header"), expectedHeader)
+	md := rcv.GetMetadata()
+	require.EqualValues(t, md.Get("header"), expectedHeader)
+	require.Equal(t, len(md.Get("User-Agent")), 1)
+	require.Contains(t, md.Get("User-Agent")[0], "Collector/1.2.3test")
 }
 
 func TestSendTracesWhenEndpointHasHttpScheme(t *testing.T) {
@@ -344,6 +349,8 @@ func TestSendMetrics(t *testing.T) {
 		},
 	}
 	set := componenttest.NewNopExporterCreateSettings()
+	set.BuildInfo.Description = "Collector"
+	set.BuildInfo.Version = "1.2.3test"
 	exp, err := factory.CreateMetricsExporter(context.Background(), set, cfg)
 	require.NoError(t, err)
 	require.NotNil(t, exp)
@@ -388,7 +395,10 @@ func TestSendMetrics(t *testing.T) {
 	assert.EqualValues(t, 4, atomic.LoadInt32(&rcv.totalItems))
 	assert.EqualValues(t, md, rcv.GetLastRequest())
 
-	require.EqualValues(t, rcv.GetMetadata().Get("header"), expectedHeader)
+	mdata := rcv.GetMetadata()
+	require.EqualValues(t, mdata.Get("header"), expectedHeader)
+	require.Equal(t, len(mdata.Get("User-Agent")), 1)
+	require.Contains(t, mdata.Get("User-Agent")[0], "Collector/1.2.3test")
 }
 
 func TestSendTraceDataServerDownAndUp(t *testing.T) {
@@ -545,6 +555,8 @@ func TestSendLogData(t *testing.T) {
 		},
 	}
 	set := componenttest.NewNopExporterCreateSettings()
+	set.BuildInfo.Description = "Collector"
+	set.BuildInfo.Version = "1.2.3test"
 	exp, err := factory.CreateLogsExporter(context.Background(), set, cfg)
 	require.NoError(t, err)
 	require.NotNil(t, exp)
@@ -586,4 +598,8 @@ func TestSendLogData(t *testing.T) {
 	assert.EqualValues(t, 2, atomic.LoadInt32(&rcv.requestCount))
 	assert.EqualValues(t, 2, atomic.LoadInt32(&rcv.totalItems))
 	assert.EqualValues(t, ld, rcv.GetLastRequest())
+
+	md := rcv.GetMetadata()
+	require.Equal(t, len(md.Get("User-Agent")), 1)
+	require.Contains(t, md.Get("User-Agent")[0], "Collector/1.2.3test")
 }

exporter/otlphttpexporter/factory.go

@@ -77,7 +77,7 @@ func createTracesExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.TracesExporter, error) {
-	oce, err := newExporter(cfg, set.Logger)
+	oce, err := newExporter(cfg, set.Logger, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -105,7 +105,7 @@ func createMetricsExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.MetricsExporter, error) {
-	oce, err := newExporter(cfg, set.Logger)
+	oce, err := newExporter(cfg, set.Logger, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -133,7 +133,7 @@ func createLogsExporter(
 	set component.ExporterCreateSettings,
 	cfg config.Exporter,
 ) (component.LogsExporter, error) {
-	oce, err := newExporter(cfg, set.Logger)
+	oce, err := newExporter(cfg, set.Logger, set.BuildInfo)
 	if err != nil {
 		return nil, err
 	}

exporter/otlphttpexporter/otlp.go

@@ -49,6 +49,7 @@ type exporter struct {
 	metricsURL string
 	logsURL    string
 	logger     *zap.Logger
+	buildInfo  component.BuildInfo
 }
 
 var (
@@ -63,7 +64,7 @@ const (
 )
 
 // Crete new exporter.
-func newExporter(cfg config.Exporter, logger *zap.Logger) (*exporter, error) {
+func newExporter(cfg config.Exporter, logger *zap.Logger, buildInfo component.BuildInfo) (*exporter, error) {
 	oCfg := cfg.(*Config)
 
 	if oCfg.Endpoint != "" {
@@ -75,14 +76,16 @@ func newExporter(cfg config.Exporter, logger *zap.Logger) (*exporter, error) {
 
 	// client construction is deferred to start
 	return &exporter{
-		config: oCfg,
-		logger: logger,
+		config:    oCfg,
+		logger:    logger,
+		buildInfo: buildInfo,
 	}, nil
 }
 
 // start actually creates the HTTP client. The client construction is deferred till this point as this
 // is the only place we get hold of Extensions which are required to construct auth round tripper.
 func (e *exporter) start(_ context.Context, host component.Host) error {
+	e.config.HTTPClientSettings.WithDefaultUserAgent(exporterhelper.DefaultUserAgent(e.buildInfo))
 	client, err := e.config.HTTPClientSettings.ToClient(host.GetExtensions())
 	if err != nil {
 		return err