internal/transport: Get rid of TargetInfo struct. (#3527)

clientconn.go

@@ -1224,16 +1224,9 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 	onCloseCalled := make(chan struct{})
 	reconnect := grpcsync.NewEvent()
 
-	authority := ac.cc.authority
 	// addr.ServerName takes precedent over ClientConn authority, if present.
-	if addr.ServerName != "" {
-		authority = addr.ServerName
-	}
-
-	target := transport.TargetInfo{
-		Addr:      addr.Addr,
-		Metadata:  addr.Metadata,
-		Authority: authority,
+	if addr.ServerName == "" {
+		addr.ServerName = ac.cc.authority
 	}
 
 	once := sync.Once{}
@@ -1279,7 +1272,7 @@ func (ac *addrConn) createTransport(addr resolver.Address, copts transport.Conne
 		copts.ChannelzParentID = ac.channelzID
 	}
 
-	newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt, onGoAway, onClose)
+	newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, addr, copts, onPrefaceReceipt, onGoAway, onClose)
 	if err != nil {
 		// newTr is either nil, or closed.
 		channelz.Warningf(ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v. Err: %v. Reconnecting...", addr, err)

internal/transport/http2_client.go

@@ -41,6 +41,7 @@ import (
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 )
@@ -161,7 +162,7 @@ func isTemporary(err error) bool {
 // newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
 // and starts to receive messages on it. Non-nil error returns if construction
 // fails.
-func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
+func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -215,7 +216,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 	}
 	if transportCreds != nil {
 		scheme = "https"
-		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.Authority, conn)
+		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.ServerName, conn)
 		if err != nil {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: authentication handshake failed: %v", err)
 		}

internal/transport/transport.go

@@ -35,6 +35,7 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/tap"
@@ -568,17 +569,10 @@ type ConnectOptions struct {
 	MaxHeaderListSize *uint32
 }
 
-// TargetInfo contains the information of the target such as network address and metadata.
-type TargetInfo struct {
-	Addr      string
-	Metadata  interface{}
-	Authority string
-}
-
 // NewClientTransport establishes the transport with the required ConnectOptions
 // and returns it to the caller.
-func NewClientTransport(connectCtx, ctx context.Context, target TargetInfo, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
-	return newHTTP2Client(connectCtx, ctx, target, opts, onPrefaceReceipt, onGoAway, onClose)
+func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
+	return newHTTP2Client(connectCtx, ctx, addr, opts, onPrefaceReceipt, onGoAway, onClose)
 }
 
 // Options provides additional hints and information for message

internal/transport/transport_test.go

@@ -40,6 +40,7 @@ import (
 	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/leakcheck"
 	"google.golang.org/grpc/internal/testutils"
+	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/status"
 )
 
@@ -430,12 +431,9 @@ func setUp(t *testing.T, port int, maxStreams uint32, ht hType) (*server, *http2
 
 func setUpWithOptions(t *testing.T, port int, serverConfig *ServerConfig, ht hType, copts ConnectOptions) (*server, *http2Client, func()) {
 	server := setUpServerOnly(t, port, serverConfig, ht)
-	addr := "localhost:" + server.port
-	target := TargetInfo{
-		Addr: addr,
-	}
+	addr := resolver.Address{Addr: "localhost:" + server.port}
 	connectCtx, cancel := context.WithDeadline(context.Background(), time.Now().Add(2*time.Second))
-	ct, connErr := NewClientTransport(connectCtx, context.Background(), target, copts, func() {}, func(GoAwayReason) {}, func() {})
+	ct, connErr := NewClientTransport(connectCtx, context.Background(), addr, copts, func() {}, func(GoAwayReason) {}, func() {})
 	if connErr != nil {
 		cancel() // Do not cancel in success path.
 		t.Fatalf("failed to create transport: %v", connErr)
@@ -460,7 +458,7 @@ func setUpWithNoPingServer(t *testing.T, copts ConnectOptions, connCh chan net.C
 		connCh <- conn
 	}()
 	connectCtx, cancel := context.WithDeadline(context.Background(), time.Now().Add(2*time.Second))
-	tr, err := NewClientTransport(connectCtx, context.Background(), TargetInfo{Addr: lis.Addr().String()}, copts, func() {}, func(GoAwayReason) {}, func() {})
+	tr, err := NewClientTransport(connectCtx, context.Background(), resolver.Address{Addr: lis.Addr().String()}, copts, func() {}, func(GoAwayReason) {}, func() {})
 	if err != nil {
 		cancel() // Do not cancel in success path.
 		// Server clean-up.
@@ -1281,7 +1279,7 @@ func (s) TestClientWithMisbehavedServer(t *testing.T) {
 	}()
 	connectCtx, cancel := context.WithDeadline(context.Background(), time.Now().Add(2*time.Second))
 	defer cancel()
-	ct, err := NewClientTransport(connectCtx, context.Background(), TargetInfo{Addr: lis.Addr().String()}, ConnectOptions{}, func() {}, func(GoAwayReason) {}, func() {})
+	ct, err := NewClientTransport(connectCtx, context.Background(), resolver.Address{Addr: lis.Addr().String()}, ConnectOptions{}, func() {}, func(GoAwayReason) {}, func() {})
 	if err != nil {
 		t.Fatalf("Error while creating client transport: %v", err)
 	}