From 1d01189f04f5187bd39e9212b7af3b3e83e86361 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 17:12:12 -0400
Subject: [PATCH 01/12] Added version checker interface

---
 registry/registry.go | 42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index fc84f19ec4..12ca3c4bfb 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -98,6 +98,35 @@ func ResolveRepositoryName(reposName string) (string, string, error) {
 	return endpoint, reposName, err
 }
 
+// VersionChecker is used to model entities which has a version.
+// It is basically a tupple with name and version.
+type VersionChecker interface {
+	Name() string
+	Version() string
+}
+
+func setUserAgentHeader(req *http.Request, baseVersions []VersionChecker, extra ...VersionChecker) error {
+	if len(baseVersions)+len(extra) == 0 {
+		return nil
+	}
+	userAgent := make(map[string]string, len(baseVersions)+len(extra))
+
+	for _, v := range baseVersions {
+		userAgent[v.Name()] = v.Version()
+	}
+	for _, v := range extra {
+		userAgent[v.Name()] = v.Version()
+	}
+
+	header, err := json.Marshal(userAgent)
+	userAgent = nil
+	if err != nil {
+		return err
+	}
+	req.Header.Set("User-Agent", string(header))
+	return nil
+}
+
 func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
 	for _, cookie := range c.Jar.Cookies(req.URL) {
 		req.AddCookie(cookie)
@@ -536,11 +565,12 @@ type ImgData struct {
 }
 
 type Registry struct {
-	client     *http.Client
-	authConfig *auth.AuthConfig
+	client       *http.Client
+	authConfig   *auth.AuthConfig
+	baseVersions []VersionChecker
 }
 
-func NewRegistry(root string, authConfig *auth.AuthConfig) (r *Registry, err error) {
+func NewRegistry(root string, authConfig *auth.AuthConfig, baseVersions ...VersionChecker) (r *Registry, err error) {
 	httpTransport := &http.Transport{
 		DisableKeepAlives: true,
 		Proxy:             http.ProxyFromEnvironment,
@@ -553,5 +583,9 @@ func NewRegistry(root string, authConfig *auth.AuthConfig) (r *Registry, err err
 		},
 	}
 	r.client.Jar, err = cookiejar.New(nil)
-	return r, err
+	if err != nil {
+		return nil, err
+	}
+	r.baseVersions = baseVersions
+	return r, nil
 }

From 1bb8f60d5ae3810b465dd3c79a7a572fb017d078 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 17:24:54 -0400
Subject: [PATCH 02/12] inserted setUserAgent in each HTTP request

---
 registry/registry.go | 43 ++++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 12ca3c4bfb..c51df1ac2d 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -105,33 +105,30 @@ type VersionChecker interface {
 	Version() string
 }
 
-func setUserAgentHeader(req *http.Request, baseVersions []VersionChecker, extra ...VersionChecker) error {
-	if len(baseVersions)+len(extra) == 0 {
-		return nil
+func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
+	for _, cookie := range c.Jar.Cookies(req.URL) {
+		req.AddCookie(cookie)
 	}
-	userAgent := make(map[string]string, len(baseVersions)+len(extra))
+	return c.Do(req)
+}
 
-	for _, v := range baseVersions {
+func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
+	if len(r.baseVersions)+len(extra) == 0 {
+		return
+	}
+	userAgent := make(map[string]string, len(r.baseVersions)+len(extra))
+
+	for _, v := range r.baseVersions {
 		userAgent[v.Name()] = v.Version()
 	}
 	for _, v := range extra {
 		userAgent[v.Name()] = v.Version()
 	}
 
-	header, err := json.Marshal(userAgent)
+	header, _ := json.Marshal(userAgent)
 	userAgent = nil
-	if err != nil {
-		return err
-	}
 	req.Header.Set("User-Agent", string(header))
-	return nil
-}
-
-func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
-	for _, cookie := range c.Jar.Cookies(req.URL) {
-		req.AddCookie(cookie)
-	}
-	return c.Do(req)
+	return
 }
 
 // Retrieve the history of a given image from the Registry.
@@ -142,6 +139,9 @@ func (r *Registry) GetRemoteHistory(imgID, registry string, token []string) ([]s
 		return nil, err
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
+	if err != nil {
+		return nil, err
+	}
 	res, err := r.client.Do(req)
 	if err != nil || res.StatusCode != 200 {
 		if res != nil {
@@ -188,6 +188,7 @@ func (r *Registry) GetRemoteImageJSON(imgID, registry string, token []string) ([
 		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
+	r.setUserAgent(req, nil)
 	res, err := r.client.Do(req)
 	if err != nil {
 		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
@@ -215,6 +216,7 @@ func (r *Registry) GetRemoteImageLayer(imgID, registry string, token []string) (
 		return nil, fmt.Errorf("Error while getting from the server: %s\n", err)
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
+	r.setUserAgent(req, nil)
 	res, err := r.client.Do(req)
 	if err != nil {
 		return nil, err
@@ -235,6 +237,7 @@ func (r *Registry) GetRemoteTags(registries []string, repository string, token [
 			return nil, err
 		}
 		req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
+		r.setUserAgent(req, nil)
 		res, err := r.client.Do(req)
 		if err != nil {
 			return nil, err
@@ -273,6 +276,7 @@ func (r *Registry) GetRepositoryData(indexEp, remote string) (*RepositoryData, e
 		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 	}
 	req.Header.Set("X-Docker-Token", "true")
+	r.setUserAgent(req, nil)
 
 	res, err := r.client.Do(req)
 	if err != nil {
@@ -336,6 +340,7 @@ func (r *Registry) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, regis
 	req.Header.Add("Content-type", "application/json")
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
 	req.Header.Set("X-Docker-Checksum", imgData.Checksum)
+	r.setUserAgent(req, nil)
 
 	utils.Debugf("Setting checksum for %s: %s", imgData.ID, imgData.Checksum)
 	res, err := doWithCookies(r.client, req)
@@ -370,6 +375,7 @@ func (r *Registry) PushImageLayerRegistry(imgID string, layer io.Reader, registr
 	req.ContentLength = -1
 	req.TransferEncoding = []string{"chunked"}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
+	r.setUserAgent(req, nil)
 	res, err := doWithCookies(r.client, req)
 	if err != nil {
 		return fmt.Errorf("Failed to upload layer: %s", err)
@@ -407,6 +413,7 @@ func (r *Registry) PushRegistryTag(remote, revision, tag, registry string, token
 	}
 	req.Header.Add("Content-type", "application/json")
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
+	r.setUserAgent(req, nil)
 	req.ContentLength = int64(len(revision))
 	res, err := doWithCookies(r.client, req)
 	if err != nil {
@@ -439,6 +446,7 @@ func (r *Registry) PushImageJSONIndex(indexEp, remote string, imgList []*ImgData
 	req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 	req.ContentLength = int64(len(imgListJSON))
 	req.Header.Set("X-Docker-Token", "true")
+	r.setUserAgent(req, nil)
 	if validate {
 		req.Header["X-Docker-Endpoints"] = regs
 	}
@@ -459,6 +467,7 @@ func (r *Registry) PushImageJSONIndex(indexEp, remote string, imgList []*ImgData
 		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 		req.ContentLength = int64(len(imgListJSON))
 		req.Header.Set("X-Docker-Token", "true")
+		r.setUserAgent(req, nil)
 		if validate {
 			req.Header["X-Docker-Endpoints"] = regs
 		}

From 65185a565b8e05a2dd58e10d1c1ad560f4a255cf Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 17:33:28 -0400
Subject: [PATCH 03/12] added APIVersion when call NewRegistry

---
 api_params.go | 12 ++++++++++++
 server.go     |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/api_params.go b/api_params.go
index b8af690c7f..217062b66f 100644
--- a/api_params.go
+++ b/api_params.go
@@ -66,6 +66,18 @@ type APIVersion struct {
 	GoVersion string `json:",omitempty"`
 }
 
+func (v *APIVersion) Name() string {
+	return "docker"
+}
+
+func (v *APIVersion) Version() string {
+	r, err := json.Marshal(v)
+	if err != nil {
+		return r.Version
+	}
+	return string(r)
+}
+
 type APIWait struct {
 	StatusCode int
 }
diff --git a/server.go b/server.go
index f1c0909516..c1ea5670e0 100644
--- a/server.go
+++ b/server.go
@@ -55,7 +55,7 @@ func (srv *Server) ContainerExport(name string, out io.Writer) error {
 }
 
 func (srv *Server) ImagesSearch(term string) ([]APISearch, error) {
-	r, err := registry.NewRegistry(srv.runtime.root, nil)
+	r, err := registry.NewRegistry(srv.runtime.root, nil, srv.DockerVersion())
 	if err != nil {
 		return nil, err
 	}
@@ -470,7 +470,7 @@ func (srv *Server) poolRemove(kind, key string) error {
 }
 
 func (srv *Server) ImagePull(localName string, tag string, out io.Writer, sf *utils.StreamFormatter, authConfig *auth.AuthConfig) error {
-	r, err := registry.NewRegistry(srv.runtime.root, authConfig)
+	r, err := registry.NewRegistry(srv.runtime.root, authConfig, srv.DockerVersion())
 	if err != nil {
 		return err
 	}
@@ -687,7 +687,7 @@ func (srv *Server) ImagePush(localName string, out io.Writer, sf *utils.StreamFo
 
 	out = utils.NewWriteFlusher(out)
 	img, err := srv.runtime.graph.Get(localName)
-	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig)
+	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig, srv.DockerVersion())
 	if err2 != nil {
 		return err2
 	}

From 5705a493080ba5571a7929d37e7926678a982cb4 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 17:42:04 -0400
Subject: [PATCH 04/12] Insert version checkers when call NewRegistry()

---
 api_params.go | 12 ------------
 server.go     | 33 ++++++++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/api_params.go b/api_params.go
index 217062b66f..b8af690c7f 100644
--- a/api_params.go
+++ b/api_params.go
@@ -66,18 +66,6 @@ type APIVersion struct {
 	GoVersion string `json:",omitempty"`
 }
 
-func (v *APIVersion) Name() string {
-	return "docker"
-}
-
-func (v *APIVersion) Version() string {
-	r, err := json.Marshal(v)
-	if err != nil {
-		return r.Version
-	}
-	return string(r)
-}
-
 type APIWait struct {
 	StatusCode int
 }
diff --git a/server.go b/server.go
index c1ea5670e0..b943ef2985 100644
--- a/server.go
+++ b/server.go
@@ -26,6 +26,33 @@ func (srv *Server) DockerVersion() APIVersion {
 	}
 }
 
+type plainVersionChecker struct {
+	name    string
+	version string
+}
+
+func (v *plainVersionChecker) Name() string {
+	return v.name
+}
+
+func (v *plainVersionChecker) Version() string {
+	return v.version
+}
+
+func (srv *Server) versionCheckers() []registry.VersionChecker {
+	v := srv.DockerVersion()
+	ret := make([]registry.VersionChecker, 0, 3)
+	ret = append(ret, &plainVersionChecker{"docker", v.Version})
+
+	if len(v.GoVersion) > 0 {
+		ret = append(ret, &plainVersionChecker{"go", v.GoVersion})
+	}
+	if len(v.GitCommit) > 0 {
+		ret = append(ret, &plainVersionChecker{"git-commit", v.GitCommit})
+	}
+	return ret
+}
+
 func (srv *Server) ContainerKill(name string) error {
 	if container := srv.runtime.Get(name); container != nil {
 		if err := container.Kill(); err != nil {
@@ -55,7 +82,7 @@ func (srv *Server) ContainerExport(name string, out io.Writer) error {
 }
 
 func (srv *Server) ImagesSearch(term string) ([]APISearch, error) {
-	r, err := registry.NewRegistry(srv.runtime.root, nil, srv.DockerVersion())
+	r, err := registry.NewRegistry(srv.runtime.root, nil, srv.versionCheckers()...)
 	if err != nil {
 		return nil, err
 	}
@@ -470,7 +497,7 @@ func (srv *Server) poolRemove(kind, key string) error {
 }
 
 func (srv *Server) ImagePull(localName string, tag string, out io.Writer, sf *utils.StreamFormatter, authConfig *auth.AuthConfig) error {
-	r, err := registry.NewRegistry(srv.runtime.root, authConfig, srv.DockerVersion())
+	r, err := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionCheckers()...)
 	if err != nil {
 		return err
 	}
@@ -687,7 +714,7 @@ func (srv *Server) ImagePush(localName string, out io.Writer, sf *utils.StreamFo
 
 	out = utils.NewWriteFlusher(out)
 	img, err := srv.runtime.graph.Get(localName)
-	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig, srv.DockerVersion())
+	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionCheckers()...)
 	if err2 != nil {
 		return err2
 	}

From d40efc4648af6bb5c60b37a789effd602af1f132 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 17:48:37 -0400
Subject: [PATCH 05/12] added client's kernel version

---
 registry/registry.go | 24 +++++++++++++++---------
 server.go            |  7 ++++++-
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index c51df1ac2d..683a64ab6a 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -119,9 +119,15 @@ func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
 	userAgent := make(map[string]string, len(r.baseVersions)+len(extra))
 
 	for _, v := range r.baseVersions {
+		if v == nil {
+			continue
+		}
 		userAgent[v.Name()] = v.Version()
 	}
 	for _, v := range extra {
+		if v == nil {
+			continue
+		}
 		userAgent[v.Name()] = v.Version()
 	}
 
@@ -188,7 +194,7 @@ func (r *Registry) GetRemoteImageJSON(imgID, registry string, token []string) ([
 		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 	res, err := r.client.Do(req)
 	if err != nil {
 		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
@@ -216,7 +222,7 @@ func (r *Registry) GetRemoteImageLayer(imgID, registry string, token []string) (
 		return nil, fmt.Errorf("Error while getting from the server: %s\n", err)
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 	res, err := r.client.Do(req)
 	if err != nil {
 		return nil, err
@@ -237,7 +243,7 @@ func (r *Registry) GetRemoteTags(registries []string, repository string, token [
 			return nil, err
 		}
 		req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
-		r.setUserAgent(req, nil)
+		r.setUserAgent(req)
 		res, err := r.client.Do(req)
 		if err != nil {
 			return nil, err
@@ -276,7 +282,7 @@ func (r *Registry) GetRepositoryData(indexEp, remote string) (*RepositoryData, e
 		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 	}
 	req.Header.Set("X-Docker-Token", "true")
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 
 	res, err := r.client.Do(req)
 	if err != nil {
@@ -340,7 +346,7 @@ func (r *Registry) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, regis
 	req.Header.Add("Content-type", "application/json")
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
 	req.Header.Set("X-Docker-Checksum", imgData.Checksum)
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 
 	utils.Debugf("Setting checksum for %s: %s", imgData.ID, imgData.Checksum)
 	res, err := doWithCookies(r.client, req)
@@ -375,7 +381,7 @@ func (r *Registry) PushImageLayerRegistry(imgID string, layer io.Reader, registr
 	req.ContentLength = -1
 	req.TransferEncoding = []string{"chunked"}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 	res, err := doWithCookies(r.client, req)
 	if err != nil {
 		return fmt.Errorf("Failed to upload layer: %s", err)
@@ -413,7 +419,7 @@ func (r *Registry) PushRegistryTag(remote, revision, tag, registry string, token
 	}
 	req.Header.Add("Content-type", "application/json")
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 	req.ContentLength = int64(len(revision))
 	res, err := doWithCookies(r.client, req)
 	if err != nil {
@@ -446,7 +452,7 @@ func (r *Registry) PushImageJSONIndex(indexEp, remote string, imgList []*ImgData
 	req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 	req.ContentLength = int64(len(imgListJSON))
 	req.Header.Set("X-Docker-Token", "true")
-	r.setUserAgent(req, nil)
+	r.setUserAgent(req)
 	if validate {
 		req.Header["X-Docker-Endpoints"] = regs
 	}
@@ -467,7 +473,7 @@ func (r *Registry) PushImageJSONIndex(indexEp, remote string, imgList []*ImgData
 		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
 		req.ContentLength = int64(len(imgListJSON))
 		req.Header.Set("X-Docker-Token", "true")
-		r.setUserAgent(req, nil)
+		r.setUserAgent(req)
 		if validate {
 			req.Header["X-Docker-Endpoints"] = regs
 		}
diff --git a/server.go b/server.go
index b943ef2985..70bb0bb871 100644
--- a/server.go
+++ b/server.go
@@ -41,7 +41,7 @@ func (v *plainVersionChecker) Version() string {
 
 func (srv *Server) versionCheckers() []registry.VersionChecker {
 	v := srv.DockerVersion()
-	ret := make([]registry.VersionChecker, 0, 3)
+	ret := make([]registry.VersionChecker, 0, 4)
 	ret = append(ret, &plainVersionChecker{"docker", v.Version})
 
 	if len(v.GoVersion) > 0 {
@@ -50,6 +50,11 @@ func (srv *Server) versionCheckers() []registry.VersionChecker {
 	if len(v.GitCommit) > 0 {
 		ret = append(ret, &plainVersionChecker{"git-commit", v.GitCommit})
 	}
+	kernelVersion, err := utils.GetKernelVersion()
+	if err == nil {
+		ret = append(ret, &plainVersionChecker{"kernel", kernelVersion.String()})
+	}
+
 	return ret
 }
 

From 26c8eae6fea53e9a78bd035614fff20086f00b17 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 18:45:45 -0400
Subject: [PATCH 06/12] Removed an unnecessary error check.

---
 registry/registry.go | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 683a64ab6a..26cefbbdef 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -145,9 +145,7 @@ func (r *Registry) GetRemoteHistory(imgID, registry string, token []string) ([]s
 		return nil, err
 	}
 	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
-	if err != nil {
-		return nil, err
-	}
+	r.setUserAgent(req)
 	res, err := r.client.Do(req)
 	if err != nil || res.StatusCode != 200 {
 		if res != nil {

From e832b01349fec2acee6ec3219dc9bfb61ad38764 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 18:46:25 -0400
Subject: [PATCH 07/12] Removed an unnecessary nil assignment

---
 registry/registry.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/registry/registry.go b/registry/registry.go
index 26cefbbdef..920f945935 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -132,7 +132,6 @@ func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
 	}
 
 	header, _ := json.Marshal(userAgent)
-	userAgent = nil
 	req.Header.Set("User-Agent", string(header))
 	return
 }

From 34cf976866f66bc77b961f4e66a9dd8aad1ffb00 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Fri, 28 Jun 2013 19:29:02 -0400
Subject: [PATCH 08/12] format in the user agent header should follow RFC 2616

---
 registry/registry.go | 59 ++++++++++++++++++++++++++++++--------------
 1 file changed, 40 insertions(+), 19 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 920f945935..0840ffbb83 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -116,23 +116,9 @@ func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
 	if len(r.baseVersions)+len(extra) == 0 {
 		return
 	}
-	userAgent := make(map[string]string, len(r.baseVersions)+len(extra))
 
-	for _, v := range r.baseVersions {
-		if v == nil {
-			continue
-		}
-		userAgent[v.Name()] = v.Version()
-	}
-	for _, v := range extra {
-		if v == nil {
-			continue
-		}
-		userAgent[v.Name()] = v.Version()
-	}
-
-	header, _ := json.Marshal(userAgent)
-	req.Header.Set("User-Agent", string(header))
+	userAgent := appendVersions(r.baseVersionsStr, extra...)
+	req.Header.Set("User-Agent", userAgent)
 	return
 }
 
@@ -577,9 +563,43 @@ type ImgData struct {
 }
 
 type Registry struct {
-	client       *http.Client
-	authConfig   *auth.AuthConfig
-	baseVersions []VersionChecker
+	client          *http.Client
+	authConfig      *auth.AuthConfig
+	baseVersions    []VersionChecker
+	baseVersionsStr string
+}
+
+func validVersion(version VersionChecker) bool {
+	stopChars := " \t\r\n/"
+	if strings.ContainsAny(version.Name(), stopChars) {
+		return false
+	}
+	if strings.ContainsAny(version.Version(), stopChars) {
+		return false
+	}
+	return true
+}
+
+func appendVersions(base string, versions ...VersionChecker) string {
+	if len(versions) == 0 {
+		return base
+	}
+
+	var buf bytes.Buffer
+	if len(base) > 0 {
+		buf.Write([]byte(base))
+	}
+
+	for _, v := range versions {
+		if !validVersion(v) {
+			continue
+		}
+		buf.Write([]byte(v.Name()))
+		buf.Write([]byte("/"))
+		buf.Write([]byte(v.Version()))
+		buf.Write([]byte(" "))
+	}
+	return buf.String()
 }
 
 func NewRegistry(root string, authConfig *auth.AuthConfig, baseVersions ...VersionChecker) (r *Registry, err error) {
@@ -599,5 +619,6 @@ func NewRegistry(root string, authConfig *auth.AuthConfig, baseVersions ...Versi
 		return nil, err
 	}
 	r.baseVersions = baseVersions
+	r.baseVersionsStr = appendVersions("", baseVersions...)
 	return r, nil
 }

From 73e79a3310f3976b61a295f45e12aead9af41962 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Mon, 1 Jul 2013 17:57:56 -0400
Subject: [PATCH 09/12] reduce the number of string copy operations.

---
 registry/registry.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 0840ffbb83..03a2890105 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -116,9 +116,11 @@ func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
 	if len(r.baseVersions)+len(extra) == 0 {
 		return
 	}
-
-	userAgent := appendVersions(r.baseVersionsStr, extra...)
-	req.Header.Set("User-Agent", userAgent)
+	if len(extra) == 0 {
+		req.Header.Set("User-Agent", r.baseVersionsStr)
+	} else {
+		req.Header.Set("User-Agent", appendVersions(r.baseVersionsStr, extra...))
+	}
 	return
 }
 

From cd209f406e889feaba50103e5ce50f7dcd23767a Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Thu, 18 Jul 2013 14:22:49 -0400
Subject: [PATCH 10/12] documentation.

---
 registry/registry.go | 8 ++++++++
 server.go            | 9 +++++++++
 2 files changed, 17 insertions(+)

diff --git a/registry/registry.go b/registry/registry.go
index 03a2890105..6ba80cbea5 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -112,6 +112,8 @@ func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
 	return c.Do(req)
 }
 
+// Set the user agent field in the header based on the versions provided
+// in NewRegistry() and extra.
 func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
 	if len(r.baseVersions)+len(extra) == 0 {
 		return
@@ -582,6 +584,12 @@ func validVersion(version VersionChecker) bool {
 	return true
 }
 
+// Convert versions to a string and append the string to the string base.
+//
+// Each VersionChecker will be converted to a string in the format of
+// "product/version", where the "product" is get from the Name() method, while
+// version is get from the Version() method. Several pieces of verson information
+// will be concatinated and separated by space.
 func appendVersions(base string, versions ...VersionChecker) string {
 	if len(versions) == 0 {
 		return base
diff --git a/server.go b/server.go
index 70bb0bb871..925e4e3386 100644
--- a/server.go
+++ b/server.go
@@ -26,6 +26,11 @@ func (srv *Server) DockerVersion() APIVersion {
 	}
 }
 
+// plainVersionChecker is a simple implementation of
+// the interface VersionChecker, which is used
+// to provide version information for some product,
+// component, etc. It stores the product name and the version
+// in string and returns them on calls to Name() and Version().
 type plainVersionChecker struct {
 	name    string
 	version string
@@ -39,6 +44,10 @@ func (v *plainVersionChecker) Version() string {
 	return v.version
 }
 
+// versionCheckers() returns version informations of:
+// docker, go, git-commit (of the docker) and the host's kernel.
+//
+// Such information will be used on call to NewRegistry().
 func (srv *Server) versionCheckers() []registry.VersionChecker {
 	v := srv.DockerVersion()
 	ret := make([]registry.VersionChecker, 0, 4)

From ede1e6d4754f3cffeac72f5d760fe4d87c5ae570 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Tue, 23 Jul 2013 17:05:13 -0400
Subject: [PATCH 11/12] Rename: VersionChecker->VersionInfo.

---
 registry/registry.go | 16 ++++++++--------
 runtime_test.go      | 12 ++++++------
 server.go            | 22 +++++++++++-----------
 3 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/registry/registry.go b/registry/registry.go
index 6ba80cbea5..e6f4f592e2 100644
--- a/registry/registry.go
+++ b/registry/registry.go
@@ -98,9 +98,9 @@ func ResolveRepositoryName(reposName string) (string, string, error) {
 	return endpoint, reposName, err
 }
 
-// VersionChecker is used to model entities which has a version.
+// VersionInfo is used to model entities which has a version.
 // It is basically a tupple with name and version.
-type VersionChecker interface {
+type VersionInfo interface {
 	Name() string
 	Version() string
 }
@@ -114,7 +114,7 @@ func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
 
 // Set the user agent field in the header based on the versions provided
 // in NewRegistry() and extra.
-func (r *Registry) setUserAgent(req *http.Request, extra ...VersionChecker) {
+func (r *Registry) setUserAgent(req *http.Request, extra ...VersionInfo) {
 	if len(r.baseVersions)+len(extra) == 0 {
 		return
 	}
@@ -569,11 +569,11 @@ type ImgData struct {
 type Registry struct {
 	client          *http.Client
 	authConfig      *auth.AuthConfig
-	baseVersions    []VersionChecker
+	baseVersions    []VersionInfo
 	baseVersionsStr string
 }
 
-func validVersion(version VersionChecker) bool {
+func validVersion(version VersionInfo) bool {
 	stopChars := " \t\r\n/"
 	if strings.ContainsAny(version.Name(), stopChars) {
 		return false
@@ -586,11 +586,11 @@ func validVersion(version VersionChecker) bool {
 
 // Convert versions to a string and append the string to the string base.
 //
-// Each VersionChecker will be converted to a string in the format of
+// Each VersionInfo will be converted to a string in the format of
 // "product/version", where the "product" is get from the Name() method, while
 // version is get from the Version() method. Several pieces of verson information
 // will be concatinated and separated by space.
-func appendVersions(base string, versions ...VersionChecker) string {
+func appendVersions(base string, versions ...VersionInfo) string {
 	if len(versions) == 0 {
 		return base
 	}
@@ -612,7 +612,7 @@ func appendVersions(base string, versions ...VersionChecker) string {
 	return buf.String()
 }
 
-func NewRegistry(root string, authConfig *auth.AuthConfig, baseVersions ...VersionChecker) (r *Registry, err error) {
+func NewRegistry(root string, authConfig *auth.AuthConfig, baseVersions ...VersionInfo) (r *Registry, err error) {
 	httpTransport := &http.Transport{
 		DisableKeepAlives: true,
 		Proxy:             http.ProxyFromEnvironment,
diff --git a/runtime_test.go b/runtime_test.go
index 6b94e5ce2c..74ca09cc8d 100644
--- a/runtime_test.go
+++ b/runtime_test.go
@@ -18,12 +18,12 @@ import (
 )
 
 const (
-	unitTestImageName	= "docker-test-image"
-	unitTestImageID		= "83599e29c455eb719f77d799bc7c51521b9551972f5a850d7ad265bc1b5292f6" // 1.0
-	unitTestNetworkBridge	= "testdockbr0"
-	unitTestStoreBase	= "/var/lib/docker/unit-tests"
-	testDaemonAddr		= "127.0.0.1:4270"
-	testDaemonProto		= "tcp"
+	unitTestImageName     = "docker-test-image"
+	unitTestImageID       = "83599e29c455eb719f77d799bc7c51521b9551972f5a850d7ad265bc1b5292f6" // 1.0
+	unitTestNetworkBridge = "testdockbr0"
+	unitTestStoreBase     = "/var/lib/docker/unit-tests"
+	testDaemonAddr        = "127.0.0.1:4270"
+	testDaemonProto       = "tcp"
 )
 
 var globalRuntime *Runtime
diff --git a/server.go b/server.go
index 925e4e3386..62c0243820 100644
--- a/server.go
+++ b/server.go
@@ -26,21 +26,21 @@ func (srv *Server) DockerVersion() APIVersion {
 	}
 }
 
-// plainVersionChecker is a simple implementation of
-// the interface VersionChecker, which is used
+// simpleVersionInfo is a simple implementation of
+// the interface VersionInfo, which is used
 // to provide version information for some product,
 // component, etc. It stores the product name and the version
 // in string and returns them on calls to Name() and Version().
-type plainVersionChecker struct {
+type simpleVersionInfo struct {
 	name    string
 	version string
 }
 
-func (v *plainVersionChecker) Name() string {
+func (v *simpleVersionInfo) Name() string {
 	return v.name
 }
 
-func (v *plainVersionChecker) Version() string {
+func (v *simpleVersionInfo) Version() string {
 	return v.version
 }
 
@@ -48,20 +48,20 @@ func (v *plainVersionChecker) Version() string {
 // docker, go, git-commit (of the docker) and the host's kernel.
 //
 // Such information will be used on call to NewRegistry().
-func (srv *Server) versionCheckers() []registry.VersionChecker {
+func (srv *Server) versionCheckers() []registry.VersionInfo {
 	v := srv.DockerVersion()
-	ret := make([]registry.VersionChecker, 0, 4)
-	ret = append(ret, &plainVersionChecker{"docker", v.Version})
+	ret := make([]registry.VersionInfo, 0, 4)
+	ret = append(ret, &simpleVersionInfo{"docker", v.Version})
 
 	if len(v.GoVersion) > 0 {
-		ret = append(ret, &plainVersionChecker{"go", v.GoVersion})
+		ret = append(ret, &simpleVersionInfo{"go", v.GoVersion})
 	}
 	if len(v.GitCommit) > 0 {
-		ret = append(ret, &plainVersionChecker{"git-commit", v.GitCommit})
+		ret = append(ret, &simpleVersionInfo{"git-commit", v.GitCommit})
 	}
 	kernelVersion, err := utils.GetKernelVersion()
 	if err == nil {
-		ret = append(ret, &plainVersionChecker{"kernel", kernelVersion.String()})
+		ret = append(ret, &simpleVersionInfo{"kernel", kernelVersion.String()})
 	}
 
 	return ret

From 1ae54707a0ee1f690a7dca17d83b5417e83704c3 Mon Sep 17 00:00:00 2001
From: Nan Monnand Deng <monnand@gmail.com>
Date: Tue, 23 Jul 2013 17:17:31 -0400
Subject: [PATCH 12/12] versionCheckers()->versionInfos().

---
 server.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/server.go b/server.go
index 62c0243820..b706ceda12 100644
--- a/server.go
+++ b/server.go
@@ -48,7 +48,7 @@ func (v *simpleVersionInfo) Version() string {
 // docker, go, git-commit (of the docker) and the host's kernel.
 //
 // Such information will be used on call to NewRegistry().
-func (srv *Server) versionCheckers() []registry.VersionInfo {
+func (srv *Server) versionInfos() []registry.VersionInfo {
 	v := srv.DockerVersion()
 	ret := make([]registry.VersionInfo, 0, 4)
 	ret = append(ret, &simpleVersionInfo{"docker", v.Version})
@@ -96,7 +96,7 @@ func (srv *Server) ContainerExport(name string, out io.Writer) error {
 }
 
 func (srv *Server) ImagesSearch(term string) ([]APISearch, error) {
-	r, err := registry.NewRegistry(srv.runtime.root, nil, srv.versionCheckers()...)
+	r, err := registry.NewRegistry(srv.runtime.root, nil, srv.versionInfos()...)
 	if err != nil {
 		return nil, err
 	}
@@ -511,7 +511,7 @@ func (srv *Server) poolRemove(kind, key string) error {
 }
 
 func (srv *Server) ImagePull(localName string, tag string, out io.Writer, sf *utils.StreamFormatter, authConfig *auth.AuthConfig) error {
-	r, err := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionCheckers()...)
+	r, err := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionInfos()...)
 	if err != nil {
 		return err
 	}
@@ -728,7 +728,7 @@ func (srv *Server) ImagePush(localName string, out io.Writer, sf *utils.StreamFo
 
 	out = utils.NewWriteFlusher(out)
 	img, err := srv.runtime.graph.Get(localName)
-	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionCheckers()...)
+	r, err2 := registry.NewRegistry(srv.runtime.root, authConfig, srv.versionInfos()...)
 	if err2 != nil {
 		return err2
 	}