@@ -21,6 +21,7 @@ import (

 	"github.com/docker/distribution/registry/client/transport"

 	"github.com/docker/docker/cliconfig"

 	"github.com/docker/docker/distribution"

+	"github.com/docker/docker/dockerversion"

 	"github.com/docker/docker/pkg/jsonmessage"

 	flag "github.com/docker/docker/pkg/mflag"

 	"github.com/docker/docker/reference"

@@ -139,7 +140,7 @@ func (cli *DockerCli) getNotaryRepository(repoInfo *registry.RepositoryInfo, aut

 	}

 	// Skip configuration headers since request is not going to Docker daemon

-	modifiers := registry.DockerHeaders(http.Header{})

+	modifiers := registry.DockerHeaders(dockerversion.DockerUserAgent(), http.Header{})

 	authTransport := transport.NewTransport(base, modifiers...)

 	pingClient := &http.Client{

 		Transport: authTransport,

@@ -41,6 +41,7 @@ import (

 	"github.com/docker/docker/distribution"

 	dmetadata "github.com/docker/docker/distribution/metadata"

 	"github.com/docker/docker/distribution/xfer"

+	"github.com/docker/docker/dockerversion"

 	derr "github.com/docker/docker/errors"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/image/tarexport"

@@ -1444,7 +1445,7 @@ func configureVolumes(config *Config, rootUID, rootGID int) (*store.VolumeStore,

 // AuthenticateToRegistry checks the validity of credentials in authConfig

 func (daemon *Daemon) AuthenticateToRegistry(authConfig *types.AuthConfig) (string, error) {

-	return daemon.RegistryService.Auth(authConfig)

+	return daemon.RegistryService.Auth(authConfig, dockerversion.DockerUserAgent())

 }

 // SearchRegistryForImages queries the registry for images matching

@@ -1452,7 +1453,7 @@ func (daemon *Daemon) AuthenticateToRegistry(authConfig *types.AuthConfig) (stri

 func (daemon *Daemon) SearchRegistryForImages(term string,

 	authConfig *types.AuthConfig,

 	headers map[string][]string) (*registrytypes.SearchResults, error) {

-	return daemon.RegistryService.Search(term, authConfig, headers)

+	return daemon.RegistryService.Search(term, authConfig, dockerversion.DockerUserAgent(), headers)

 }

 // IsShuttingDown tells whether the daemon is shutting down or not

@@ -19,7 +19,6 @@ import (

 // ImagePullConfig stores pull configuration.

 type ImagePullConfig struct {

 	// MetaHeaders stores HTTP headers with metadata about the image

-	// (DockerHeaders with prefix X-Meta- in the request).

 	MetaHeaders map[string][]string

 	// AuthConfig holds authentication credentials for authenticating with

 	// the registry.

@@ -14,6 +14,7 @@ import (

 	"github.com/docker/distribution/registry/client/transport"

 	"github.com/docker/docker/distribution/metadata"

 	"github.com/docker/docker/distribution/xfer"

+	"github.com/docker/docker/dockerversion"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/image/v1"

 	"github.com/docker/docker/layer"

@@ -47,10 +48,10 @@ func (p *v1Puller) Pull(ctx context.Context, ref reference.Named) error {

 	tr := transport.NewTransport(

 		// TODO(tiborvass): was ReceiveTimeout

 		registry.NewTransport(tlsConfig),

-		registry.DockerHeaders(p.config.MetaHeaders)...,

+		registry.DockerHeaders(dockerversion.DockerUserAgent(), p.config.MetaHeaders)...,

 	)

 	client := registry.HTTPClient(tr)

-	v1Endpoint, err := p.endpoint.ToV1Endpoint(p.config.MetaHeaders)

+	v1Endpoint, err := p.endpoint.ToV1Endpoint(dockerversion.DockerUserAgent(), p.config.MetaHeaders)

 	if err != nil {

 		logrus.Debugf("Could not get v1 endpoint: %v", err)

 		return fallbackError{err: err}

@@ -22,7 +22,6 @@ import (

 // ImagePushConfig stores push configuration.

 type ImagePushConfig struct {

 	// MetaHeaders store HTTP headers with metadata about the image

-	// (DockerHeaders with prefix X-Meta- in the request).

 	MetaHeaders map[string][]string

 	// AuthConfig holds authentication credentials for authenticating with

 	// the registry.

@@ -8,6 +8,7 @@ import (

 	"github.com/docker/distribution/digest"

 	"github.com/docker/distribution/registry/client/transport"

 	"github.com/docker/docker/distribution/metadata"

+	"github.com/docker/docker/dockerversion"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/image/v1"

 	"github.com/docker/docker/layer"

@@ -38,10 +39,10 @@ func (p *v1Pusher) Push(ctx context.Context) error {

 	tr := transport.NewTransport(

 		// TODO(tiborvass): was NoTimeout

 		registry.NewTransport(tlsConfig),

-		registry.DockerHeaders(p.config.MetaHeaders)...,

+		registry.DockerHeaders(dockerversion.DockerUserAgent(), p.config.MetaHeaders)...,

 	)

 	client := registry.HTTPClient(tr)

-	v1Endpoint, err := p.endpoint.ToV1Endpoint(p.config.MetaHeaders)

+	v1Endpoint, err := p.endpoint.ToV1Endpoint(dockerversion.DockerUserAgent(), p.config.MetaHeaders)

 	if err != nil {

 		logrus.Debugf("Could not get v1 endpoint: %v", err)

 		return fallbackError{err: err}

@@ -15,6 +15,7 @@ import (

 	"github.com/docker/distribution/registry/client/auth"

 	"github.com/docker/distribution/registry/client/transport"

 	"github.com/docker/docker/distribution/xfer"

+	"github.com/docker/docker/dockerversion"

 	"github.com/docker/docker/registry"

 	"github.com/docker/engine-api/types"

 	"golang.org/x/net/context"

@@ -68,7 +69,7 @@ func NewV2Repository(ctx context.Context, repoInfo *registry.RepositoryInfo, end

 		DisableKeepAlives: true,

 	}

-	modifiers := registry.DockerHeaders(metaHeaders)

+	modifiers := registry.DockerHeaders(dockerversion.DockerUserAgent(), metaHeaders)

 	authTransport := transport.NewTransport(base, modifiers...)

 	pingClient := &http.Client{

 		Transport: authTransport,

new file mode 100644

@@ -0,0 +1,24 @@

+package dockerversion

+

+import (

+	"runtime"

+

+	"github.com/docker/docker/pkg/parsers/kernel"

+	"github.com/docker/docker/pkg/useragent"

+)

+

+// DockerUserAgent is the User-Agent the Docker client uses to identify itself.

+// It is populated from version information of different components.

+func DockerUserAgent() string {

+	httpVersion := make([]useragent.VersionInfo, 0, 6)

+	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "docker", Version: Version})

+	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "go", Version: runtime.Version()})

+	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "git-commit", Version: GitCommit})

+	if kernelVersion, err := kernel.GetKernelVersion(); err == nil {

+		httpVersion = append(httpVersion, useragent.VersionInfo{Name: "kernel", Version: kernelVersion.String()})

+	}

+	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "os", Version: runtime.GOOS})

+	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "arch", Version: runtime.GOARCH})

+

+	return useragent.AppendVersions("", httpVersion...)

+}

@@ -45,12 +45,12 @@ func scanForAPIVersion(address string) (string, APIVersion) {

 // NewEndpoint parses the given address to return a registry endpoint.  v can be used to

 // specify a specific endpoint version

-func NewEndpoint(index *registrytypes.IndexInfo, metaHeaders http.Header, v APIVersion) (*Endpoint, error) {

+func NewEndpoint(index *registrytypes.IndexInfo, userAgent string, metaHeaders http.Header, v APIVersion) (*Endpoint, error) {

 	tlsConfig, err := newTLSConfig(index.Name, index.Secure)

 	if err != nil {

 		return nil, err

 	}

-	endpoint, err := newEndpoint(GetAuthConfigKey(index), tlsConfig, metaHeaders)

+	endpoint, err := newEndpoint(GetAuthConfigKey(index), tlsConfig, userAgent, metaHeaders)

 	if err != nil {

 		return nil, err

 	}

@@ -91,7 +91,7 @@ func validateEndpoint(endpoint *Endpoint) error {

 	return nil

 }

-func newEndpoint(address string, tlsConfig *tls.Config, metaHeaders http.Header) (*Endpoint, error) {

+func newEndpoint(address string, tlsConfig *tls.Config, userAgent string, metaHeaders http.Header) (*Endpoint, error) {

 	var (

 		endpoint       = new(Endpoint)

 		trimmedAddress string

@@ -112,7 +112,7 @@ func newEndpoint(address string, tlsConfig *tls.Config, metaHeaders http.Header)

 	// TODO(tiborvass): make sure a ConnectTimeout transport is used

 	tr := NewTransport(tlsConfig)

-	endpoint.client = HTTPClient(transport.NewTransport(tr, DockerHeaders(metaHeaders)...))

+	endpoint.client = HTTPClient(transport.NewTransport(tr, DockerHeaders(userAgent, metaHeaders)...))

 	return endpoint, nil

 }

@@ -19,7 +19,7 @@ func TestEndpointParse(t *testing.T) {

 		{"0.0.0.0:5000", "https://0.0.0.0:5000/v0/"},

 	}

 	for _, td := range testData {

-		e, err := newEndpoint(td.str, nil, nil)

+		e, err := newEndpoint(td.str, nil, "", nil)

 		if err != nil {

 			t.Errorf("%q: %s", td.str, err)

 		}

@@ -21,9 +21,6 @@ import (

 	"github.com/docker/distribution/registry/api/v2"

 	"github.com/docker/distribution/registry/client"

 	"github.com/docker/distribution/registry/client/transport"

-	"github.com/docker/docker/dockerversion"

-	"github.com/docker/docker/pkg/parsers/kernel"

-	"github.com/docker/docker/pkg/useragent"

 	"github.com/docker/go-connections/tlsconfig"

 )

@@ -34,23 +31,7 @@ var (

 	errLoginRequired = errors.New("Authentication is required.")

 )

-// dockerUserAgent is the User-Agent the Docker client uses to identify itself.

-// It is populated on init(), comprising version information of different components.

-var dockerUserAgent string

-

 func init() {

-	httpVersion := make([]useragent.VersionInfo, 0, 6)

-	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "docker", Version: dockerversion.Version})

-	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "go", Version: runtime.Version()})

-	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "git-commit", Version: dockerversion.GitCommit})

-	if kernelVersion, err := kernel.GetKernelVersion(); err == nil {

-		httpVersion = append(httpVersion, useragent.VersionInfo{Name: "kernel", Version: kernelVersion.String()})

-	}

-	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "os", Version: runtime.GOOS})

-	httpVersion = append(httpVersion, useragent.VersionInfo{Name: "arch", Version: runtime.GOARCH})

-

-	dockerUserAgent = useragent.AppendVersions("", httpVersion...)

-

 	if runtime.GOOS != "linux" {

 		V2Only = true

 	}

@@ -130,12 +111,13 @@ func ReadCertsDirectory(tlsConfig *tls.Config, directory string) error {

 	return nil

 }

-// DockerHeaders returns request modifiers that ensure requests have

-// the User-Agent header set to dockerUserAgent and that metaHeaders

-// are added.

-func DockerHeaders(metaHeaders http.Header) []transport.RequestModifier {

-	modifiers := []transport.RequestModifier{

-		transport.NewHeaderRequestModifier(http.Header{"User-Agent": []string{dockerUserAgent}}),

+// DockerHeaders returns request modifiers with a User-Agent and metaHeaders

+func DockerHeaders(userAgent string, metaHeaders http.Header) []transport.RequestModifier {

+	modifiers := []transport.RequestModifier{}

+	if userAgent != "" {

+		modifiers = append(modifiers, transport.NewHeaderRequestModifier(http.Header{

+			"User-Agent": []string{userAgent},

+		}))

 	}

 	if metaHeaders != nil {

 		modifiers = append(modifiers, transport.NewHeaderRequestModifier(metaHeaders))

@@ -25,12 +25,13 @@ const (

 func spawnTestRegistrySession(t *testing.T) *Session {

 	authConfig := &types.AuthConfig{}

-	endpoint, err := NewEndpoint(makeIndex("/v1/"), nil, APIVersionUnknown)

+	endpoint, err := NewEndpoint(makeIndex("/v1/"), "", nil, APIVersionUnknown)

 	if err != nil {

 		t.Fatal(err)

 	}

+	userAgent := "docker test client"

 	var tr http.RoundTripper = debugTransport{NewTransport(nil), t.Log}

-	tr = transport.NewTransport(AuthTransport(tr, authConfig, false), DockerHeaders(nil)...)

+	tr = transport.NewTransport(AuthTransport(tr, authConfig, false), DockerHeaders(userAgent, nil)...)

 	client := HTTPClient(tr)

 	r, err := NewSession(client, authConfig, endpoint)

 	if err != nil {

@@ -52,7 +53,7 @@ func spawnTestRegistrySession(t *testing.T) *Session {

 func TestPingRegistryEndpoint(t *testing.T) {

 	testPing := func(index *registrytypes.IndexInfo, expectedStandalone bool, assertMessage string) {

-		ep, err := NewEndpoint(index, nil, APIVersionUnknown)

+		ep, err := NewEndpoint(index, "", nil, APIVersionUnknown)

 		if err != nil {

 			t.Fatal(err)

 		}

@@ -72,7 +73,7 @@ func TestPingRegistryEndpoint(t *testing.T) {

 func TestEndpoint(t *testing.T) {

 	// Simple wrapper to fail test if err != nil

 	expandEndpoint := func(index *registrytypes.IndexInfo) *Endpoint {

-		endpoint, err := NewEndpoint(index, nil, APIVersionUnknown)

+		endpoint, err := NewEndpoint(index, "", nil, APIVersionUnknown)

 		if err != nil {

 			t.Fatal(err)

 		}

@@ -81,7 +82,7 @@ func TestEndpoint(t *testing.T) {

 	assertInsecureIndex := func(index *registrytypes.IndexInfo) {

 		index.Secure = true

-		_, err := NewEndpoint(index, nil, APIVersionUnknown)

+		_, err := NewEndpoint(index, "", nil, APIVersionUnknown)

 		assertNotEqual(t, err, nil, index.Name+": Expected error for insecure index")

 		assertEqual(t, strings.Contains(err.Error(), "insecure-registry"), true, index.Name+": Expected insecure-registry  error for insecure index")

 		index.Secure = false

@@ -89,7 +90,7 @@ func TestEndpoint(t *testing.T) {

 	assertSecureIndex := func(index *registrytypes.IndexInfo) {

 		index.Secure = true

-		_, err := NewEndpoint(index, nil, APIVersionUnknown)

+		_, err := NewEndpoint(index, "", nil, APIVersionUnknown)

 		assertNotEqual(t, err, nil, index.Name+": Expected cert error for secure index")

 		assertEqual(t, strings.Contains(err.Error(), "certificate signed by unknown authority"), true, index.Name+": Expected cert error for secure index")

 		index.Secure = false

@@ -155,7 +156,7 @@ func TestEndpoint(t *testing.T) {

 	}

 	for _, address := range badEndpoints {

 		index.Name = address

-		_, err := NewEndpoint(index, nil, APIVersionUnknown)

+		_, err := NewEndpoint(index, "", nil, APIVersionUnknown)

 		checkNotEqual(t, err, nil, "Expected error while expanding bad endpoint")

 	}

 }

@@ -28,7 +28,7 @@ func NewService(options *Options) *Service {

 // Auth contacts the public registry with the provided credentials,

 // and returns OK if authentication was successful.

 // It can be used to verify the validity of a client's credentials.

-func (s *Service) Auth(authConfig *types.AuthConfig) (string, error) {

+func (s *Service) Auth(authConfig *types.AuthConfig, userAgent string) (string, error) {

 	addr := authConfig.ServerAddress

 	if addr == "" {

 		// Use the official registry address if not specified.

@@ -45,7 +45,7 @@ func (s *Service) Auth(authConfig *types.AuthConfig) (string, error) {

 		endpointVersion = APIVersion2

 	}

-	endpoint, err := NewEndpoint(index, nil, endpointVersion)

+	endpoint, err := NewEndpoint(index, userAgent, nil, endpointVersion)

 	if err != nil {

 		return "", err

 	}

@@ -72,7 +72,7 @@ func splitReposSearchTerm(reposName string) (string, string) {

 // Search queries the public registry for images matching the specified

 // search terms, and returns the results.

-func (s *Service) Search(term string, authConfig *types.AuthConfig, headers map[string][]string) (*registrytypes.SearchResults, error) {

+func (s *Service) Search(term string, authConfig *types.AuthConfig, userAgent string, headers map[string][]string) (*registrytypes.SearchResults, error) {

 	if err := validateNoSchema(term); err != nil {

 		return nil, err

 	}

@@ -85,7 +85,7 @@ func (s *Service) Search(term string, authConfig *types.AuthConfig, headers map[

 	}

 	// *TODO: Search multiple indexes.

-	endpoint, err := NewEndpoint(index, http.Header(headers), APIVersionUnknown)

+	endpoint, err := NewEndpoint(index, userAgent, http.Header(headers), APIVersionUnknown)

 	if err != nil {

 		return nil, err

 	}

@@ -129,8 +129,8 @@ type APIEndpoint struct {

 }

 // ToV1Endpoint returns a V1 API endpoint based on the APIEndpoint

-func (e APIEndpoint) ToV1Endpoint(metaHeaders http.Header) (*Endpoint, error) {

-	return newEndpoint(e.URL, e.TLSConfig, metaHeaders)

+func (e APIEndpoint) ToV1Endpoint(userAgent string, metaHeaders http.Header) (*Endpoint, error) {

+	return newEndpoint(e.URL, e.TLSConfig, userAgent, metaHeaders)

 }

 // TLSConfig constructs a client TLS configuration based on server defaults