Add User-Agent header to OTLP exporter requests (#3261)

* Add User-Agent header to OTLP exporter requests
* allow override grpc user-agent

Signed-off-by: rogerogers <rogers@rogerogers.com>

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 default User-Agent header to OTLP exporter requests (`go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetricgrpc`, `go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetrichttp`, `go.opentelemetry.io/otel/exporters/otlptrace/otlptracegrpc` and `go.opentelemetry.io/otel/exporters/otlptrace/otlptracehttp`). (#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/internal/oconf/options.go

@@ -104,6 +104,7 @@ func NewGRPCConfig(opts ...GRPCOption) Config {
 			Timeout:     DefaultTimeout,
 		},
 		RetryConfig: retry.DefaultConfig,
+		DialOptions: []grpc.DialOption{grpc.WithUserAgent(internal.GetUserAgentHeader())},
 	}
 	cfg = ApplyGRPCEnvConfigs(cfg)
 	for _, opt := range opts {

exporters/otlp/otlpmetric/otlpmetricgrpc/client_test.go

@@ -22,6 +22,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"google.golang.org/genproto/googleapis/rpc/errdetails"
+	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/durationpb"
@@ -169,6 +170,7 @@ 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]})
 	})
@@ -188,4 +190,18 @@ func TestConfig(t *testing.T) {
 		err := exp.Export(ctx, metricdata.ResourceMetrics{})
 		assert.ErrorContains(t, err, context.DeadlineExceeded.Error())
 	})
+
+	t.Run("WithCustomUserAgent", func(t *testing.T) {
+		key := "user-agent"
+		customerUserAgent := "custom-user-agent"
+		exp, coll := factoryFunc(nil, WithDialOption(grpc.WithUserAgent(customerUserAgent)))
+		t.Cleanup(coll.Shutdown)
+		ctx := context.Background()
+		require.NoError(t, exp.Export(ctx, metricdata.ResourceMetrics{}))
+		// Ensure everything is flushed.
+		require.NoError(t, exp.Shutdown(ctx))
+
+		got := coll.Headers()
+		assert.Contains(t, got[key][0], customerUserAgent)
+	})
 }

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]})
 	})
@@ -161,4 +162,19 @@ func TestConfig(t *testing.T) {
 		assert.NoError(t, exp.Export(ctx, metricdata.ResourceMetrics{}))
 		assert.Len(t, coll.Collect().Dump(), 1)
 	})
+
+	t.Run("WithCustomUserAgent", func(t *testing.T) {
+		key := http.CanonicalHeaderKey("user-agent")
+		headers := map[string]string{key: "custom-user-agent"}
+		exp, coll := factoryFunc("", nil, WithHeaders(headers))
+		ctx := context.Background()
+		t.Cleanup(func() { require.NoError(t, coll.Shutdown(ctx)) })
+		require.NoError(t, exp.Export(ctx, metricdata.ResourceMetrics{}))
+		// Ensure everything is flushed.
+		require.NoError(t, exp.Shutdown(ctx))
+
+		got := coll.Headers()
+		require.Contains(t, got, key)
+		assert.Equal(t, got[key], []string{headers[key]})
+	})
 }

exporters/otlp/otlpmetric/otlpmetrichttp/go.mod

@@ -4,6 +4,7 @@ go 1.18
 
 require (
 	github.com/stretchr/testify v1.7.1
+	go.opentelemetry.io/otel v1.10.0
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.10.0
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.32.1
 	go.opentelemetry.io/otel/metric v0.32.1
@@ -21,7 +22,6 @@ require (
 	github.com/google/go-cmp v0.5.8 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	go.opentelemetry.io/otel v1.10.0 // indirect
 	go.opentelemetry.io/otel/sdk v1.10.0 // indirect
 	go.opentelemetry.io/otel/trace v1.10.0 // indirect
 	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect

exporters/otlp/otlptrace/internal/otlpconfig/options.go

@@ -97,6 +97,7 @@ func NewGRPCConfig(opts ...GRPCOption) Config {
 			Timeout:     DefaultTimeout,
 		},
 		RetryConfig: retry.DefaultConfig,
+		DialOptions: []grpc.DialOption{grpc.WithUserAgent(internal.GetUserAgentHeader())},
 	}
 	cfg = ApplyGRPCEnvConfigs(cfg)
 	for _, opt := range opts {

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])
 }
@@ -411,3 +412,18 @@ func TestPartialSuccess(t *testing.T) {
 	require.Contains(t, errors[0].Error(), "partially successful")
 	require.Contains(t, errors[0].Error(), "2 spans rejected")
 }
+
+func TestCustomUserAgent(t *testing.T) {
+	customUserAgent := "custom-user-agent"
+	mc := runMockCollector(t)
+	t.Cleanup(func() { require.NoError(t, mc.stop()) })
+
+	ctx := context.Background()
+	exp := newGRPCExporter(t, ctx, mc.endpoint,
+		otlptracegrpc.WithDialOption(grpc.WithUserAgent(customUserAgent)))
+	t.Cleanup(func() { require.NoError(t, exp.Shutdown(ctx)) })
+	require.NoError(t, exp.ExportSpans(ctx, roSpans))
+
+	headers := mc.getHeaders()
+	require.Contains(t, headers.Get("user-agent")[0], customUserAgent)
+}

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)
 	}

exporters/otlp/otlptrace/otlptracehttp/client_test.go

@@ -42,6 +42,10 @@ var (
 		"Otel-Go-Key-1": "somevalue",
 		"Otel-Go-Key-2": "someothervalue",
 	}
+
+	customUserAgentHeader = map[string]string{
+		"user-agent": "custome-user-agent",
+	}
 )
 
 func TestEndToEnd(t *testing.T) {
@@ -142,6 +146,15 @@ func TestEndToEnd(t *testing.T) {
 				ExpectedHeaders: testHeaders,
 			},
 		},
+		{
+			name: "with custom user agent",
+			opts: []otlptracehttp.Option{
+				otlptracehttp.WithHeaders(customUserAgentHeader),
+			},
+			mcCfg: mockCollectorConfig{
+				ExpectedHeaders: customUserAgentHeader,
+			},
+		},
 	}
 
 	for _, tc := range tests {