spanner: remove redundant x-goog-api-client header

The Spanner client now uses the gapic client, which automatically
sets the x-goog-api-client header, so this header should no longer
be set by the client itself.

Fixes #1524

Change-Id: Ib7523878a7d94f7e5a05b5caec6fc3312316c72c
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/43671
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>

spanner/client.go

@@ -25,7 +25,6 @@ import (
 	"time"
 
 	"cloud.google.com/go/internal/trace"
-	"cloud.google.com/go/internal/version"
 	vkit "cloud.google.com/go/spanner/apiv1"
 	"cloud.google.com/go/spanner/internal/backoff"
 	"google.golang.org/api/option"
@@ -41,10 +40,6 @@ const (
 	// resourcePrefixHeader is the name of the metadata header used to indicate
 	// the resource being operated on.
 	resourcePrefixHeader = "google-cloud-resource-prefix"
-
-	// xGoogHeaderKey is the name of the metadata header used to indicate client
-	// information.
-	xGoogHeaderKey = "x-goog-api-client"
 )
 
 const (
@@ -57,7 +52,6 @@ const (
 
 var (
 	validDBPattern = regexp.MustCompile("^projects/[^/]+/instances/[^/]+/databases/[^/]+$")
-	xGoogHeaderVal = fmt.Sprintf("gl-go/%s gccl/%s grpc/%s", version.Go(), version.Repo, grpc.Version)
 )
 
 func validDatabaseName(db string) error {
@@ -125,9 +119,7 @@ func NewClient(ctx context.Context, database string, opts ...option.ClientOption
 func NewClientWithConfig(ctx context.Context, database string, config ClientConfig, opts ...option.ClientOption) (c *Client, err error) {
 	c = &Client{
 		database: database,
-		md: metadata.Pairs(
-			resourcePrefixHeader, database,
-			xGoogHeaderKey, xGoogHeaderVal),
+		md:       metadata.Pairs(resourcePrefixHeader, database),
 	}
 
 	// Make a copy of labels.

spanner/client_test.go

@@ -26,7 +26,9 @@ import (
 	"cloud.google.com/go/spanner/internal/benchserver"
 	"cloud.google.com/go/spanner/internal/testutil"
 	"google.golang.org/api/iterator"
+	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
 	gstatus "google.golang.org/grpc/status"
 )
 
@@ -435,3 +437,50 @@ func TestNewClient_ConnectToEmulator(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestClient_ApiClientHeader(t *testing.T) {
+	t.Parallel()
+	server, client := newSpannerInMemTestServerWithInterceptor(t, func(
+		ctx context.Context,
+		method string,
+		req interface{},
+		reply interface{},
+		cc *grpc.ClientConn,
+		invoker grpc.UnaryInvoker,
+		opts ...grpc.CallOption,
+	) error {
+		// Check that the x-goog-api-client is set.
+		headers, ok := metadata.FromOutgoingContext(ctx)
+		if !ok {
+			return spannerErrorf(codes.Internal, "could not get outgoing metadata")
+		}
+		token, ok := headers["x-goog-api-client"]
+		if !ok {
+			return spannerErrorf(codes.Internal, "could not get api client token")
+		}
+		if token == nil {
+			return spannerErrorf(codes.Internal, "nil-value for outgoing api client token")
+		}
+		if len(token) != 1 {
+			return spannerErrorf(codes.Internal, "unexpected number of api client token headers: %v", len(token))
+		}
+		if !strings.HasPrefix(token[0], "gl-go/") {
+			return spannerErrorf(codes.Internal, "unexpected api client token: %v", token[0])
+		}
+		return invoker(ctx, method, req, reply, cc, opts...)
+	},
+	)
+	defer server.teardown(client)
+	ctx := context.Background()
+	iter := client.Single().Query(ctx, NewStatement(selectSingerIDAlbumIDAlbumTitleFromAlbums))
+	defer iter.Stop()
+	for {
+		_, err := iter.Next()
+		if err == iterator.Done {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+}

spanner/mocked_inmem_server.go

@@ -56,18 +56,25 @@ func newSpannerInMemTestServer(t *testing.T) (*spannerInMemTestServer, *Client)
 	return s, client
 }
 
+// Create a spannerInMemTestServer with default configuration and a client interceptor.
+func newSpannerInMemTestServerWithInterceptor(t *testing.T, interceptor grpc.UnaryClientInterceptor) (*spannerInMemTestServer, *Client) {
+	s := &spannerInMemTestServer{}
+	client := s.setupWithConfig(t, ClientConfig{}, interceptor)
+	return s, client
+}
+
 // Create a spannerInMemTestServer with the specified configuration.
 func newSpannerInMemTestServerWithConfig(t *testing.T, config ClientConfig) (*spannerInMemTestServer, *Client) {
 	s := &spannerInMemTestServer{}
-	client := s.setupWithConfig(t, config)
+	client := s.setupWithConfig(t, config, nil)
 	return s, client
 }
 
 func (s *spannerInMemTestServer) setup(t *testing.T) *Client {
-	return s.setupWithConfig(t, ClientConfig{})
+	return s.setupWithConfig(t, ClientConfig{}, nil)
 }
 
-func (s *spannerInMemTestServer) setupWithConfig(t *testing.T, config ClientConfig) *Client {
+func (s *spannerInMemTestServer) setupWithConfig(t *testing.T, config ClientConfig, interceptor grpc.UnaryClientInterceptor) *Client {
 	s.testSpanner = testutil.NewInMemSpannerServer()
 	s.setupFooResults()
 	s.setupSingersResults()
@@ -83,11 +90,15 @@ func (s *spannerInMemTestServer) setupWithConfig(t *testing.T, config ClientConf
 	serverAddress := lis.Addr().String()
 	ctx := context.Background()
 	var formattedDatabase = fmt.Sprintf("projects/%s/instances/%s/databases/%s", "[PROJECT]", "[INSTANCE]", "[DATABASE]")
-	client, err := NewClientWithConfig(ctx, formattedDatabase, config,
+	opts := []option.ClientOption{
 		option.WithEndpoint(serverAddress),
 		option.WithGRPCDialOption(grpc.WithInsecure()),
 		option.WithoutAuthentication(),
-	)
+	}
+	if interceptor != nil {
+		opts = append(opts, option.WithGRPCDialOption(grpc.WithUnaryInterceptor(interceptor)))
+	}
+	client, err := NewClientWithConfig(ctx, formattedDatabase, config, opts...)
 	if err != nil {
 		t.Fatal(err)
 	}