Add User-Agent header to OTLP exporter requests

CHANGELOG.md

@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 
 - Added an example of using metric views to customize instruments. (#3177)
+- Add User-Agent header to OTLP exporter requests (#3261)
 
 ### Changed
 

exporters/otlp/internal/header.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package internal contains common functionality for all OTLP exporters.
+package internal // import "go.opentelemetry.io/otel/exporters/otlp/internal"
+
+import "go.opentelemetry.io/otel"
+
+// GetUserAgentHeader return an OTLP header value form "OTel OTLP Exporter Go/{{ .Version }}"
+// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/protocol/exporter.md#user-agent
+func GetUserAgentHeader() string {
+	return "OTel OTLP Exporter Go/" + otel.Version()
+}

exporters/otlp/internal/header_test.go

@@ -0,0 +1,26 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package internal contains common functionality for all OTLP exporters.
+package internal // import "go.opentelemetry.io/otel/exporters/otlp/internal"
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetUserAgentHeader(t *testing.T) {
+	require.Regexp(t, "OTel OTLP Exporter Go/1\\..*", GetUserAgentHeader())
+}

exporters/otlp/otlpmetric/otlpmetricgrpc/client.go

@@ -24,6 +24,7 @@ import (
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
 
+	"go.opentelemetry.io/otel/exporters/otlp/internal"
 	"go.opentelemetry.io/otel/exporters/otlp/internal/retry"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/oconf"
@@ -77,6 +78,8 @@ func newClient(ctx context.Context, options ...Option) (otlpmetric.Client, error
 	}
 
 	if c.conn == nil {
+		// Add a User-Agent header when no ClientConn was provided
+		cfg.DialOptions = append(cfg.DialOptions, grpc.WithUserAgent(internal.GetUserAgentHeader()))
 		// If the caller did not provide a ClientConn when the client was
 		// created, create one using the configuration they did provide.
 		conn, err := grpc.DialContext(ctx, cfg.Metrics.Endpoint, cfg.DialOptions...)

exporters/otlp/otlpmetric/otlpmetricgrpc/client_test.go

@@ -169,6 +169,7 @@ func TestConfig(t *testing.T) {
 		require.NoError(t, exp.Shutdown(ctx))
 
 		got := coll.Headers()
+		require.Regexp(t, "OTel OTLP Exporter Go/1\\..*", got)
 		require.Contains(t, got, key)
 		assert.Equal(t, got[key], []string{headers[key]})
 	})

exporters/otlp/otlpmetric/otlpmetrichttp/client.go

@@ -29,6 +29,7 @@ import (
 
 	"google.golang.org/protobuf/proto"
 
+	"go.opentelemetry.io/otel/exporters/otlp/internal"
 	"go.opentelemetry.io/otel/exporters/otlp/internal/retry"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/oconf"
@@ -101,6 +102,8 @@ func newClient(opts ...Option) (otlpmetric.Client, error) {
 		return nil, err
 	}
 
+	req.Header.Set("User-Agent", internal.GetUserAgentHeader())
+
 	if n := len(cfg.Metrics.Headers); n > 0 {
 		for k, v := range cfg.Metrics.Headers {
 			req.Header.Set(k, v)

exporters/otlp/otlpmetric/otlpmetrichttp/client_test.go

@@ -75,6 +75,7 @@ func TestConfig(t *testing.T) {
 		require.NoError(t, exp.Shutdown(ctx))
 
 		got := coll.Headers()
+		require.Regexp(t, "OTel OTLP Exporter Go/1\\..*", got)
 		require.Contains(t, got, key)
 		assert.Equal(t, got[key], []string{headers[key]})
 	})

exporters/otlp/otlptrace/otlptracegrpc/client.go

@@ -91,6 +91,8 @@ func newClient(opts ...Option) *client {
 // Start establishes a gRPC connection to the collector.
 func (c *client) Start(ctx context.Context) error {
 	if c.conn == nil {
+		// Add a User-Agent header when no ClientConn was provided
+		c.dialOpts = append(c.dialOpts, grpc.WithUserAgent(internal.GetUserAgentHeader()))
 		// If the caller did not provide a ClientConn when the client was
 		// created, create one using the configuration they did provide.
 		conn, err := grpc.DialContext(ctx, c.endpoint, c.dialOpts...)

exporters/otlp/otlptrace/otlptracegrpc/client_test.go

@@ -212,6 +212,7 @@ func TestNewWithHeaders(t *testing.T) {
 	require.NoError(t, exp.ExportSpans(ctx, roSpans))
 
 	headers := mc.getHeaders()
+	require.Regexp(t, "OTel OTLP Exporter Go/1\\..*", headers.Get("user-agent"))
 	require.Len(t, headers.Get("header1"), 1)
 	assert.Equal(t, "value1", headers.Get("header1")[0])
 }

exporters/otlp/otlptrace/otlptracehttp/client.go

@@ -208,6 +208,8 @@ func (d *client) newRequest(body []byte) (request, error) {
 		return request{Request: r}, err
 	}
 
+	r.Header.Set("User-Agent", internal.GetUserAgentHeader())
+
 	for k, v := range d.cfg.Headers {
 		r.Header.Set(k, v)
 	}