Prevent push and pull to v1 registries by filtering the available endpoints.

Add a daemon flag to control this behaviour.  Add a warning message when pulling
an image from a v1 registry.  The default order of pull is slightly altered
with this changset.

Previously it was:
https v2, https v1, http v2, http v1

now it is:
https v2, http v2, https v1, http v1

Prevent login to v1 registries by explicitly setting the version before ping to
prevent fallback to v1.

Add unit tests for v2 only mode.  Create a mock server that can register
handlers for various endpoints.  Assert no v1 endpoints are hit with legacy
registries disabled for the following commands:  pull, push, build, run and
login.  Assert the opposite when legacy registries are not disabled.

Signed-off-by: Richard Scothern <richard.scothern@gmail.com>

docs/config.go

@@ -44,6 +44,10 @@ var (
 	ErrInvalidRepositoryName = errors.New("Invalid repository name (ex: \"registry.domain.tld/myrepos\")")
 
 	emptyServiceConfig = NewServiceConfig(nil)
+
+	// V2Only controls access to legacy registries.  If it is set to true via the
+	// command line flag the daemon will not attempt to contact v1 legacy registries
+	V2Only = false
 )
 
 // InstallFlags adds command-line options to the top-level flag parser for
@@ -53,6 +57,7 @@ func (options *Options) InstallFlags(cmd *flag.FlagSet, usageFn func(string) str
 	cmd.Var(&options.Mirrors, []string{"-registry-mirror"}, usageFn("Preferred Docker registry mirror"))
 	options.InsecureRegistries = opts.NewListOpts(ValidateIndexName)
 	cmd.Var(&options.InsecureRegistries, []string{"-insecure-registry"}, usageFn("Enable insecure registry communication"))
+	cmd.BoolVar(&V2Only, []string{"-no-legacy-registry"}, false, "Do not contact legacy registries")
 }
 
 type netIPNet net.IPNet

docs/endpoint.go

@@ -42,8 +42,9 @@ func scanForAPIVersion(address string) (string, APIVersion) {
 	return address, APIVersionUnknown
 }
 
-// NewEndpoint parses the given address to return a registry endpoint.
+// NewEndpoint parses the given address to return a registry endpoint.  v can be used to
-func NewEndpoint(index *IndexInfo, metaHeaders http.Header) (*Endpoint, error) {
+// specify a specific endpoint version
+func NewEndpoint(index *IndexInfo, metaHeaders http.Header, v APIVersion) (*Endpoint, error) {
 	tlsConfig, err := newTLSConfig(index.Name, index.Secure)
 	if err != nil {
 		return nil, err
@@ -52,6 +53,9 @@ func NewEndpoint(index *IndexInfo, metaHeaders http.Header) (*Endpoint, error) {
 	if err != nil {
 		return nil, err
 	}
+	if v != APIVersionUnknown {
+		endpoint.Version = v
+	}
 	if err := validateEndpoint(endpoint); err != nil {
 		return nil, err
 	}
@@ -111,11 +115,6 @@ func newEndpoint(address string, tlsConfig *tls.Config, metaHeaders http.Header)
 	return endpoint, nil
 }
 
-// GetEndpoint returns a new endpoint with the specified headers
-func (repoInfo *RepositoryInfo) GetEndpoint(metaHeaders http.Header) (*Endpoint, error) {
-	return NewEndpoint(repoInfo.Index, metaHeaders)
-}
-
 // Endpoint stores basic information about a registry endpoint.
 type Endpoint struct {
 	client         *http.Client

docs/registry.go

@@ -49,6 +49,10 @@ func init() {
 	httpVersion = append(httpVersion, useragent.VersionInfo{"arch", runtime.GOARCH})
 
 	dockerUserAgent = useragent.AppendVersions("", httpVersion...)
+
+	if runtime.GOOS != "linux" {
+		V2Only = true
+	}
 }
 
 func newTLSConfig(hostname string, isSecure bool) (*tls.Config, error) {

docs/registry_test.go

@@ -23,7 +23,7 @@ const (
 
 func spawnTestRegistrySession(t *testing.T) *Session {
 	authConfig := &cliconfig.AuthConfig{}
-	endpoint, err := NewEndpoint(makeIndex("/v1/"), nil)
+	endpoint, err := NewEndpoint(makeIndex("/v1/"), nil, APIVersionUnknown)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -50,7 +50,7 @@ func spawnTestRegistrySession(t *testing.T) *Session {
 
 func TestPingRegistryEndpoint(t *testing.T) {
 	testPing := func(index *IndexInfo, expectedStandalone bool, assertMessage string) {
-		ep, err := NewEndpoint(index, nil)
+		ep, err := NewEndpoint(index, nil, APIVersionUnknown)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -70,7 +70,7 @@ func TestPingRegistryEndpoint(t *testing.T) {
 func TestEndpoint(t *testing.T) {
 	// Simple wrapper to fail test if err != nil
 	expandEndpoint := func(index *IndexInfo) *Endpoint {
-		endpoint, err := NewEndpoint(index, nil)
+		endpoint, err := NewEndpoint(index, nil, APIVersionUnknown)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -79,7 +79,7 @@ func TestEndpoint(t *testing.T) {
 
 	assertInsecureIndex := func(index *IndexInfo) {
 		index.Secure = true
-		_, err := NewEndpoint(index, nil)
+		_, 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
@@ -87,7 +87,7 @@ func TestEndpoint(t *testing.T) {
 
 	assertSecureIndex := func(index *IndexInfo) {
 		index.Secure = true
-		_, err := NewEndpoint(index, nil)
+		_, 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
@@ -153,7 +153,7 @@ func TestEndpoint(t *testing.T) {
 	}
 	for _, address := range badEndpoints {
 		index.Name = address
-		_, err := NewEndpoint(index, nil)
+		_, err := NewEndpoint(index, nil, APIVersionUnknown)
 		checkNotEqual(t, err, nil, "Expected error while expanding bad endpoint")
 	}
 }

docs/service.go

@@ -2,15 +2,11 @@ package registry
 
 import (
 	"crypto/tls"
-	"fmt"
 	"net/http"
 	"net/url"
-	"runtime"
-	"strings"
 
 	"github.com/docker/distribution/registry/client/auth"
 	"github.com/docker/docker/cliconfig"
-	"github.com/docker/docker/pkg/tlsconfig"
 )
 
 // Service is a registry service. It tracks configuration data such as a list
@@ -40,7 +36,14 @@ func (s *Service) Auth(authConfig *cliconfig.AuthConfig) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	endpoint, err := NewEndpoint(index, nil)
+
+	endpointVersion := APIVersion(APIVersionUnknown)
+	if V2Only {
+		// Override the endpoint to only attempt a v2 ping
+		endpointVersion = APIVersion2
+	}
+
+	endpoint, err := NewEndpoint(index, nil, endpointVersion)
 	if err != nil {
 		return "", err
 	}
@@ -57,10 +60,11 @@ func (s *Service) Search(term string, authConfig *cliconfig.AuthConfig, headers
 	}
 
 	// *TODO: Search multiple indexes.
-	endpoint, err := repoInfo.GetEndpoint(http.Header(headers))
+	endpoint, err := NewEndpoint(repoInfo.Index, http.Header(headers), APIVersionUnknown)
 	if err != nil {
 		return nil, err
 	}
+
 	r, err := NewSession(endpoint.client, authConfig, endpoint)
 	if err != nil {
 		return nil, err
@@ -132,97 +136,20 @@ func (s *Service) LookupPushEndpoints(repoName string) (endpoints []APIEndpoint,
 }
 
 func (s *Service) lookupEndpoints(repoName string) (endpoints []APIEndpoint, err error) {
-	var cfg = tlsconfig.ServerDefault
+	endpoints, err = s.lookupV2Endpoints(repoName)
-	tlsConfig := &cfg
-	if strings.HasPrefix(repoName, DefaultNamespace+"/") {
-		// v2 mirrors
-		for _, mirror := range s.Config.Mirrors {
-			mirrorTLSConfig, err := s.tlsConfigForMirror(mirror)
-			if err != nil {
-				return nil, err
-			}
-			endpoints = append(endpoints, APIEndpoint{
-				URL: mirror,
-				// guess mirrors are v2
-				Version:      APIVersion2,
-				Mirror:       true,
-				TrimHostname: true,
-				TLSConfig:    mirrorTLSConfig,
-			})
-		}
-		// v2 registry
-		endpoints = append(endpoints, APIEndpoint{
-			URL:          DefaultV2Registry,
-			Version:      APIVersion2,
-			Official:     true,
-			TrimHostname: true,
-			TLSConfig:    tlsConfig,
-		})
-		if runtime.GOOS == "linux" { // do not inherit legacy API for OSes supported in the future
-			// v1 registry
-			endpoints = append(endpoints, APIEndpoint{
-				URL:          DefaultV1Registry,
-				Version:      APIVersion1,
-				Official:     true,
-				TrimHostname: true,
-				TLSConfig:    tlsConfig,
-			})
-		}
-		return endpoints, nil
-	}
-
-	slashIndex := strings.IndexRune(repoName, '/')
-	if slashIndex <= 0 {
-		return nil, fmt.Errorf("invalid repo name: missing '/':  %s", repoName)
-	}
-	hostname := repoName[:slashIndex]
-
-	tlsConfig, err = s.TLSConfig(hostname)
 	if err != nil {
 		return nil, err
 	}
-	isSecure := !tlsConfig.InsecureSkipVerify
 
-	v2Versions := []auth.APIVersion{
+	if V2Only {
-		{
+		return endpoints, nil
-			Type:    "registry",
-			Version: "2.0",
-		},
-	}
-	endpoints = []APIEndpoint{
-		{
-			URL:           "https://" + hostname,
-			Version:       APIVersion2,
-			TrimHostname:  true,
-			TLSConfig:     tlsConfig,
-			VersionHeader: DefaultRegistryVersionHeader,
-			Versions:      v2Versions,
-		},
-		{
-			URL:          "https://" + hostname,
-			Version:      APIVersion1,
-			TrimHostname: true,
-			TLSConfig:    tlsConfig,
-		},
 	}
 
-	if !isSecure {
+	legacyEndpoints, err := s.lookupV1Endpoints(repoName)
-		endpoints = append(endpoints, APIEndpoint{
+	if err != nil {
-			URL:          "http://" + hostname,
+		return nil, err
-			Version:      APIVersion2,
-			TrimHostname: true,
-			// used to check if supposed to be secure via InsecureSkipVerify
-			TLSConfig:     tlsConfig,
-			VersionHeader: DefaultRegistryVersionHeader,
-			Versions:      v2Versions,
-		}, APIEndpoint{
-			URL:          "http://" + hostname,
-			Version:      APIVersion1,
-			TrimHostname: true,
-			// used to check if supposed to be secure via InsecureSkipVerify
-			TLSConfig: tlsConfig,
-		})
 	}
+	endpoints = append(endpoints, legacyEndpoints...)
 
 	return endpoints, nil
 }

docs/service_v1.go

@@ -0,0 +1,54 @@
+package registry
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/docker/docker/pkg/tlsconfig"
+)
+
+func (s *Service) lookupV1Endpoints(repoName string) (endpoints []APIEndpoint, err error) {
+	var cfg = tlsconfig.ServerDefault
+	tlsConfig := &cfg
+	if strings.HasPrefix(repoName, DefaultNamespace+"/") {
+		endpoints = append(endpoints, APIEndpoint{
+			URL:          DefaultV1Registry,
+			Version:      APIVersion1,
+			Official:     true,
+			TrimHostname: true,
+			TLSConfig:    tlsConfig,
+		})
+		return endpoints, nil
+	}
+
+	slashIndex := strings.IndexRune(repoName, '/')
+	if slashIndex <= 0 {
+		return nil, fmt.Errorf("invalid repo name: missing '/':  %s", repoName)
+	}
+	hostname := repoName[:slashIndex]
+
+	tlsConfig, err = s.TLSConfig(hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	endpoints = []APIEndpoint{
+		{
+			URL:          "https://" + hostname,
+			Version:      APIVersion1,
+			TrimHostname: true,
+			TLSConfig:    tlsConfig,
+		},
+	}
+
+	if tlsConfig.InsecureSkipVerify {
+		endpoints = append(endpoints, APIEndpoint{ // or this
+			URL:          "http://" + hostname,
+			Version:      APIVersion1,
+			TrimHostname: true,
+			// used to check if supposed to be secure via InsecureSkipVerify
+			TLSConfig: tlsConfig,
+		})
+	}
+	return endpoints, nil
+}

docs/service_v2.go

@@ -0,0 +1,83 @@
+package registry
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/docker/distribution/registry/client/auth"
+	"github.com/docker/docker/pkg/tlsconfig"
+)
+
+func (s *Service) lookupV2Endpoints(repoName string) (endpoints []APIEndpoint, err error) {
+	var cfg = tlsconfig.ServerDefault
+	tlsConfig := &cfg
+	if strings.HasPrefix(repoName, DefaultNamespace+"/") {
+		// v2 mirrors
+		for _, mirror := range s.Config.Mirrors {
+			mirrorTLSConfig, err := s.tlsConfigForMirror(mirror)
+			if err != nil {
+				return nil, err
+			}
+			endpoints = append(endpoints, APIEndpoint{
+				URL: mirror,
+				// guess mirrors are v2
+				Version:      APIVersion2,
+				Mirror:       true,
+				TrimHostname: true,
+				TLSConfig:    mirrorTLSConfig,
+			})
+		}
+		// v2 registry
+		endpoints = append(endpoints, APIEndpoint{
+			URL:          DefaultV2Registry,
+			Version:      APIVersion2,
+			Official:     true,
+			TrimHostname: true,
+			TLSConfig:    tlsConfig,
+		})
+
+		return endpoints, nil
+	}
+
+	slashIndex := strings.IndexRune(repoName, '/')
+	if slashIndex <= 0 {
+		return nil, fmt.Errorf("invalid repo name: missing '/':  %s", repoName)
+	}
+	hostname := repoName[:slashIndex]
+
+	tlsConfig, err = s.TLSConfig(hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	v2Versions := []auth.APIVersion{
+		{
+			Type:    "registry",
+			Version: "2.0",
+		},
+	}
+	endpoints = []APIEndpoint{
+		{
+			URL:           "https://" + hostname,
+			Version:       APIVersion2,
+			TrimHostname:  true,
+			TLSConfig:     tlsConfig,
+			VersionHeader: DefaultRegistryVersionHeader,
+			Versions:      v2Versions,
+		},
+	}
+
+	if tlsConfig.InsecureSkipVerify {
+		endpoints = append(endpoints, APIEndpoint{
+			URL:          "http://" + hostname,
+			Version:      APIVersion2,
+			TrimHostname: true,
+			// used to check if supposed to be secure via InsecureSkipVerify
+			TLSConfig:     tlsConfig,
+			VersionHeader: DefaultRegistryVersionHeader,
+			Versions:      v2Versions,
+		})
+	}
+
+	return endpoints, nil
+}