From 7621679beee3d4ddf47411574f9fa48a1f759dbf Mon Sep 17 00:00:00 2001
From: Piotr Kowalczuk <p.kowalczuk.priv@gmail.com>
Date: Fri, 31 Jan 2020 12:34:44 -0600
Subject: [PATCH] stats: add client side user agent to outgoing header (#3331)

---
 internal/transport/http2_client.go |  5 +++--
 stats/stats_test.go                | 11 ++++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/internal/transport/http2_client.go b/internal/transport/http2_client.go
index 2d6feeb1..6043701e 100644
--- a/internal/transport/http2_client.go
+++ b/internal/transport/http2_client.go
@@ -680,14 +680,15 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 		}
 	}
 	if t.statsHandler != nil {
-		header, _, _ := metadata.FromOutgoingContextRaw(ctx)
+		header, _ := metadata.FromOutgoingContext(ctx)
+		header.Set("user-agent", t.userAgent)
 		outHeader := &stats.OutHeader{
 			Client:      true,
 			FullMethod:  callHdr.Method,
 			RemoteAddr:  t.remoteAddr,
 			LocalAddr:   t.localAddr,
 			Compression: callHdr.SendCompress,
-			Header:      header.Copy(),
+			Header:      header,
 		}
 		t.statsHandler.HandleRPC(s.ctx, outHeader)
 	}
diff --git a/stats/stats_test.go b/stats/stats_test.go
index 30248c05..1b83fe63 100644
--- a/stats/stats_test.go
+++ b/stats/stats_test.go
@@ -46,8 +46,9 @@ type rpcCtxKey struct{}
 var (
 	// For headers sent to server:
 	testMetadata = metadata.MD{
-		"key1": []string{"value1"},
-		"key2": []string{"value2"},
+		"key1":       []string{"value1"},
+		"key2":       []string{"value2"},
+		"user-agent": []string{fmt.Sprintf("test/0.0.1 grpc-go/%s", grpc.Version)},
 	}
 	// For headers sent from server:
 	testHeaderMetadata = metadata.MD{
@@ -220,7 +221,11 @@ func (te *test) clientConn() *grpc.ClientConn {
 	if te.cc != nil {
 		return te.cc
 	}
-	opts := []grpc.DialOption{grpc.WithInsecure(), grpc.WithBlock()}
+	opts := []grpc.DialOption{
+		grpc.WithInsecure(),
+		grpc.WithBlock(),
+		grpc.WithUserAgent("test/0.0.1"),
+	}
 	if te.compress == "gzip" {
 		opts = append(opts,
 			grpc.WithCompressor(grpc.NewGZIPCompressor()),