refactor: use client to retrieve token from context

exporter/sapmexporter/exporter.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/jaegertracing/jaeger/model"
 	sapmclient "github.com/signalfx/sapm-proto/client"
+	"go.opentelemetry.io/collector/client"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/consumer/consumererror"
@@ -23,14 +24,6 @@ import (
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/jaeger"
 )
 
-type contextKey string
-
-const sapmAccessTokenContextKey contextKey = splunk.SFxAccessTokenHeader
-
-func (k contextKey) String() string {
-	return string(k)
-}
-
 // TODO: Find a place for this to be shared.
 type baseTracesExporter struct {
 	component.Component
@@ -138,17 +131,17 @@ func (se *sapmExporter) retrieveAccessToken(ctx context.Context, md ptrace.Resou
 		return ""
 	}
 
-	var token string
-	if ctxAccessToken, ok := ctx.Value(sapmAccessTokenContextKey).(string); ok {
-		token = ctxAccessToken
-	} else {
-		attrs := md.Resource().Attributes()
-		if accessToken, ok := attrs.Get(splunk.SFxAccessTokenLabel); ok {
-			token = accessToken.Str()
-		}
+	cl := client.FromContext(ctx)
+	ss := cl.Metadata.Get(splunk.SFxAccessTokenHeader)
+	if len(ss) > 0 {
+		return ss[0]
 	}
 
-	return token
+	attrs := md.Resource().Attributes()
+	if accessToken, ok := attrs.Get(splunk.SFxAccessTokenLabel); ok {
+		return accessToken.Str()
+	}
+	return ""
 }
 
 // filterToken filters the access token from the batch processor to avoid leaking credentials to the backend.

exporter/sapmexporter/exporter_test.go

@@ -18,6 +18,7 @@ import (
 	splunksapm "github.com/signalfx/sapm-proto/gen"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/client"
 	"go.opentelemetry.io/collector/exporter/exportertest"
 	"go.opentelemetry.io/collector/pdata/ptrace"
 
@@ -275,7 +276,12 @@ func TestSAPMClientTokenAccess(t *testing.T) {
 
 			ctx := context.Background()
 			if tt.inContext {
-				ctx = context.WithValue(ctx, sapmAccessTokenContextKey, "SplunkAccessToken")
+				ctx = client.NewContext(
+					ctx,
+					client.Info{Metadata: client.NewMetadata(
+						map[string][]string{splunk.SFxAccessTokenHeader: {"SplunkAccessToken"}},
+					)},
+				)
 			}
 			err = se.pushTraceData(ctx, trace)
 			require.NoError(t, err)

exporter/sapmexporter/go.mod

@@ -51,6 +51,7 @@ require (
 	github.com/prometheus/procfs v0.15.1 // indirect
 	go.opencensus.io v0.24.0 // indirect
 	go.opentelemetry.io/collector v0.109.0 // indirect
+	go.opentelemetry.io/collector/client v1.15.0 // indirect
 	go.opentelemetry.io/collector/config/configtelemetry v0.109.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumerprofiles v0.109.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumertest v0.109.0 // indirect