Revert "Remove the rest of v1 manifest support"

This reverts commit 98fc09128b3f8221680bd22c2de5b893bd3d7ef8 in order to
keep registry v2 schema1 handling and libtrust-key-based engine ID.

Because registry v2 schema1 was not officially deprecated and
registries are still relying on it, this patch puts its logic back.

However, registry v1 relics are not added back since v1 logic has been
removed a while ago.

This also fixes an engine upgrade issue in a swarm cluster. It was relying
on the Engine ID to be the same upon upgrade, but the mentioned commit
modified the logic to use UUID and from a different file.

Since the libtrust key is always needed to support v2 schema1 pushes,
that the old engine ID is based on the libtrust key, and that the engine ID
needs to be conserved across upgrades, adding a UUID-based engine ID logic
seems to add more complexity than it solves the problems.

Hence reverting the engine ID changes as well.

Signed-off-by: Tibor Vass <tibor@docker.com>

cmd/dockerd/config.go

@@ -12,6 +12,8 @@ import (
 const (
 	// defaultShutdownTimeout is the default shutdown timeout for the daemon
 	defaultShutdownTimeout = 15
+	// defaultTrustKeyFile is the default filename for the trust key
+	defaultTrustKeyFile = "key.json"
 )
 
 // installCommonConfigFlags adds flags to the pflag.FlagSet to configure the daemon
@@ -81,6 +83,13 @@ func installCommonConfigFlags(conf *config.Config, flags *pflag.FlagSet) error {
 
 	flags.IntVar(&conf.NetworkControlPlaneMTU, "network-control-plane-mtu", config.DefaultNetworkMtu, "Network Control plane MTU")
 
+	// "--deprecated-key-path" is to allow configuration of the key used
+	// for the daemon ID and the deprecated image signing. It was never
+	// exposed as a command line option but is added here to allow
+	// overriding the default path in configuration.
+	flags.Var(opts.NewQuotedString(&conf.TrustKeyPath), "deprecated-key-path", "Path to key file for ID and image signing")
+	flags.MarkHidden("deprecated-key-path")
+
 	conf.MaxConcurrentDownloads = &maxConcurrentDownloads
 	conf.MaxConcurrentUploads = &maxConcurrentUploads
 	return nil
@@ -94,4 +103,10 @@ func installRegistryServiceFlags(options *registry.ServiceOptions, flags *pflag.
 	flags.Var(ana, "allow-nondistributable-artifacts", "Allow push of nondistributable artifacts to registry")
 	flags.Var(mirrors, "registry-mirror", "Preferred Docker registry mirror")
 	flags.Var(insecureRegistries, "insecure-registry", "Enable insecure registry communication")
+
+	if runtime.GOOS != "windows" {
+		// TODO: Remove this flag after 3 release cycles (18.03)
+		flags.BoolVar(&options.V2Only, "disable-legacy-registry", true, "Disable contacting legacy registries")
+		flags.MarkHidden("disable-legacy-registry")
+	}
 }

cmd/dockerd/daemon.go

@@ -429,6 +429,14 @@ func loadDaemonCliConfig(opts *daemonOptions) (*config.Config, error) {
 		conf.CommonTLSOptions.KeyFile = opts.TLSOptions.KeyFile
 	}
 
+	if conf.TrustKeyPath == "" {
+		daemonConfDir, err := getDaemonConfDir(conf.Root)
+		if err != nil {
+			return nil, err
+		}
+		conf.TrustKeyPath = filepath.Join(daemonConfDir, defaultTrustKeyFile)
+	}
+
 	if flags.Changed("graph") && flags.Changed("data-root") {
 		return nil, errors.New(`cannot specify both "--graph" and "--data-root" option`)
 	}
@@ -451,6 +459,17 @@ func loadDaemonCliConfig(opts *daemonOptions) (*config.Config, error) {
 		return nil, err
 	}
 
+	if runtime.GOOS != "windows" {
+		if flags.Changed("disable-legacy-registry") {
+			// TODO: Remove this error after 3 release cycles (18.03)
+			return nil, errors.New("ERROR: The '--disable-legacy-registry' flag has been removed. Interacting with legacy (v1) registries is no longer supported")
+		}
+		if !conf.V2Only {
+			// TODO: Remove this error after 3 release cycles (18.03)
+			return nil, errors.New("ERROR: The 'disable-legacy-registry' configuration option has been removed. Interacting with legacy (v1) registries is no longer supported")
+		}
+	}
+
 	if flags.Changed("graph") {
 		logrus.Warnf(`The "-g / --graph" flag is deprecated. Please use "--data-root" instead`)
 	}

cmd/dockerd/daemon_unix.go

@@ -58,6 +58,10 @@ func setDefaultUmask() error {
 	return nil
 }
 
+func getDaemonConfDir(_ string) (string, error) {
+	return getDefaultDaemonConfigDir()
+}
+
 func (cli *DaemonCli) getPlatformContainerdDaemonOpts() ([]supervisor.DaemonOpt, error) {
 	opts := []supervisor.DaemonOpt{
 		supervisor.WithOOMScore(cli.Config.OOMScoreAdjust),

cmd/dockerd/daemon_windows.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"path/filepath"
 	"time"
 
 	"github.com/docker/docker/daemon/config"
@@ -23,6 +24,10 @@ func setDefaultUmask() error {
 	return nil
 }
 
+func getDaemonConfDir(root string) (string, error) {
+	return filepath.Join(root, `\config`), nil
+}
+
 // preNotifySystem sends a message to the host when the API is active, but before the daemon is
 func preNotifySystem() {
 	// start the service now to prevent timeouts waiting for daemon to start

daemon/config/config.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 	"os"
 	"reflect"
+	"runtime"
 	"strings"
 	"sync"
 
@@ -134,6 +135,12 @@ type CommonConfig struct {
 	SocketGroup           string                    `json:"group,omitempty"`
 	CorsHeaders           string                    `json:"api-cors-header,omitempty"`
 
+	// TrustKeyPath is used to generate the daemon ID and for signing schema 1 manifests
+	// when pushing to a registry which does not support schema 2. This field is marked as
+	// deprecated because schema 1 manifests are deprecated in favor of schema 2 and the
+	// daemon ID will use a dedicated identifier not shared with exported signatures.
+	TrustKeyPath string `json:"deprecated-key-path,omitempty"`
+
 	// LiveRestoreEnabled determines whether we should keep containers
 	// alive upon daemon shutdown/start
 	LiveRestoreEnabled bool `json:"live-restore,omitempty"`
@@ -240,6 +247,9 @@ func New() *Config {
 	config.LogConfig.Config = make(map[string]string)
 	config.ClusterOpts = make(map[string]string)
 
+	if runtime.GOOS != "linux" {
+		config.V2Only = true
+	}
 	return &config
 }
 

daemon/daemon.go

@@ -973,7 +973,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 		return nil, err
 	}
 
-	uuid, err := loadOrCreateUUID(filepath.Join(config.Root, "engine_uuid"))
+	trustKey, err := loadOrCreateTrustKey(config.TrustKeyPath)
 	if err != nil {
 		return nil, err
 	}
@@ -1018,7 +1018,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 		return nil, errors.New("Devices cgroup isn't mounted")
 	}
 
-	d.ID = uuid
+	d.ID = trustKey.PublicKey().KeyID()
 	d.repository = daemonRepo
 	d.containers = container.NewMemoryStore()
 	if d.containersReplica, err = container.NewViewDB(); err != nil {
@@ -1049,6 +1049,7 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 		MaxConcurrentUploads:      *config.MaxConcurrentUploads,
 		ReferenceStore:            rs,
 		RegistryService:           registryService,
+		TrustKey:                  trustKey,
 	})
 
 	go d.execCommandGC()

daemon/images/image_push.go

@@ -54,6 +54,7 @@ func (i *ImageService) PushImage(ctx context.Context, image, tag string, metaHea
 		},
 		ConfigMediaType: schema2.MediaTypeImageConfig,
 		LayerStores:     distribution.NewLayerProvidersFromStores(i.layerStores),
+		TrustKey:        i.trustKey,
 		UploadManager:   i.uploadManager,
 	}
 

daemon/images/service.go

@@ -14,6 +14,7 @@ import (
 	"github.com/docker/docker/layer"
 	dockerreference "github.com/docker/docker/reference"
 	"github.com/docker/docker/registry"
+	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -39,6 +40,7 @@ type ImageServiceConfig struct {
 	MaxConcurrentUploads      int
 	ReferenceStore            dockerreference.Store
 	RegistryService           registry.Service
+	TrustKey                  libtrust.PrivateKey
 }
 
 // NewImageService returns a new ImageService from a configuration
@@ -54,6 +56,7 @@ func NewImageService(config ImageServiceConfig) *ImageService {
 		layerStores:               config.LayerStores,
 		referenceStore:            config.ReferenceStore,
 		registryService:           config.RegistryService,
+		trustKey:                  config.TrustKey,
 		uploadManager:             xfer.NewLayerUploadManager(config.MaxConcurrentUploads),
 	}
 }
@@ -69,6 +72,7 @@ type ImageService struct {
 	pruneRunning              int32
 	referenceStore            dockerreference.Store
 	registryService           registry.Service
+	trustKey                  libtrust.PrivateKey
 	uploadManager             *xfer.LayerUploadManager
 }
 

daemon/trustkey.go

@@ -0,0 +1,57 @@
+package daemon // import "github.com/docker/docker/daemon"
+
+import (
+	"encoding/json"
+	"encoding/pem"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/docker/docker/pkg/ioutils"
+	"github.com/docker/docker/pkg/system"
+	"github.com/docker/libtrust"
+)
+
+// LoadOrCreateTrustKey attempts to load the libtrust key at the given path,
+// otherwise generates a new one
+// TODO: this should use more of libtrust.LoadOrCreateTrustKey which may need
+// a refactor or this function to be moved into libtrust
+func loadOrCreateTrustKey(trustKeyPath string) (libtrust.PrivateKey, error) {
+	err := system.MkdirAll(filepath.Dir(trustKeyPath), 0755, "")
+	if err != nil {
+		return nil, err
+	}
+	trustKey, err := libtrust.LoadKeyFile(trustKeyPath)
+	if err == libtrust.ErrKeyFileDoesNotExist {
+		trustKey, err = libtrust.GenerateECP256PrivateKey()
+		if err != nil {
+			return nil, fmt.Errorf("Error generating key: %s", err)
+		}
+		encodedKey, err := serializePrivateKey(trustKey, filepath.Ext(trustKeyPath))
+		if err != nil {
+			return nil, fmt.Errorf("Error serializing key: %s", err)
+		}
+		if err := ioutils.AtomicWriteFile(trustKeyPath, encodedKey, os.FileMode(0600)); err != nil {
+			return nil, fmt.Errorf("Error saving key file: %s", err)
+		}
+	} else if err != nil {
+		return nil, fmt.Errorf("Error loading key file %s: %s", trustKeyPath, err)
+	}
+	return trustKey, nil
+}
+
+func serializePrivateKey(key libtrust.PrivateKey, ext string) (encoded []byte, err error) {
+	if ext == ".json" || ext == ".jwk" {
+		encoded, err = json.Marshal(key)
+		if err != nil {
+			return nil, fmt.Errorf("unable to encode private key JWK: %s", err)
+		}
+	} else {
+		pemBlock, err := key.PEMBlock()
+		if err != nil {
+			return nil, fmt.Errorf("unable to encode private key PEM: %s", err)
+		}
+		encoded = pem.EncodeToMemory(pemBlock)
+	}
+	return
+}

daemon/trustkey_test.go

@@ -0,0 +1,71 @@
+package daemon // import "github.com/docker/docker/daemon"
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gotest.tools/assert"
+	is "gotest.tools/assert/cmp"
+	"gotest.tools/fs"
+)
+
+// LoadOrCreateTrustKey
+func TestLoadOrCreateTrustKeyInvalidKeyFile(t *testing.T) {
+	tmpKeyFolderPath, err := ioutil.TempDir("", "api-trustkey-test")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tmpKeyFolderPath)
+
+	tmpKeyFile, err := ioutil.TempFile(tmpKeyFolderPath, "keyfile")
+	assert.NilError(t, err)
+
+	_, err = loadOrCreateTrustKey(tmpKeyFile.Name())
+	assert.Check(t, is.ErrorContains(err, "Error loading key file"))
+}
+
+func TestLoadOrCreateTrustKeyCreateKeyWhenFileDoesNotExist(t *testing.T) {
+	tmpKeyFolderPath := fs.NewDir(t, "api-trustkey-test")
+	defer tmpKeyFolderPath.Remove()
+
+	// Without the need to create the folder hierarchy
+	tmpKeyFile := tmpKeyFolderPath.Join("keyfile")
+
+	key, err := loadOrCreateTrustKey(tmpKeyFile)
+	assert.NilError(t, err)
+	assert.Check(t, key != nil)
+
+	_, err = os.Stat(tmpKeyFile)
+	assert.NilError(t, err, "key file doesn't exist")
+}
+
+func TestLoadOrCreateTrustKeyCreateKeyWhenDirectoryDoesNotExist(t *testing.T) {
+	tmpKeyFolderPath := fs.NewDir(t, "api-trustkey-test")
+	defer tmpKeyFolderPath.Remove()
+	tmpKeyFile := tmpKeyFolderPath.Join("folder/hierarchy/keyfile")
+
+	key, err := loadOrCreateTrustKey(tmpKeyFile)
+	assert.NilError(t, err)
+	assert.Check(t, key != nil)
+
+	_, err = os.Stat(tmpKeyFile)
+	assert.NilError(t, err, "key file doesn't exist")
+}
+
+func TestLoadOrCreateTrustKeyCreateKeyNoPath(t *testing.T) {
+	defer os.Remove("keyfile")
+	key, err := loadOrCreateTrustKey("keyfile")
+	assert.NilError(t, err)
+	assert.Check(t, key != nil)
+
+	_, err = os.Stat("keyfile")
+	assert.NilError(t, err, "key file doesn't exist")
+}
+
+func TestLoadOrCreateTrustKeyLoadValidKey(t *testing.T) {
+	tmpKeyFile := filepath.Join("testdata", "keyfile")
+	key, err := loadOrCreateTrustKey(tmpKeyFile)
+	assert.NilError(t, err)
+	expected := "AWX2:I27X:WQFX:IOMK:CNAK:O7PW:VYNB:ZLKC:CVAE:YJP2:SI4A:XXAY"
+	assert.Check(t, is.Contains(key.String(), expected))
+}

daemon/uuid.go

@@ -1,35 +0,0 @@
-package daemon // import "github.com/docker/docker/daemon"
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-	"path/filepath"
-
-	"github.com/docker/docker/pkg/ioutils"
-	"github.com/google/uuid"
-)
-
-func loadOrCreateUUID(path string) (string, error) {
-	err := os.MkdirAll(filepath.Dir(path), 0755)
-	if err != nil {
-		return "", err
-	}
-	var id string
-	idb, err := ioutil.ReadFile(path)
-	if os.IsNotExist(err) {
-		id = uuid.New().String()
-		if err := ioutils.AtomicWriteFile(path, []byte(id), os.FileMode(0600)); err != nil {
-			return "", fmt.Errorf("Error saving uuid file: %s", err)
-		}
-	} else if err != nil {
-		return "", fmt.Errorf("Error loading uuid file %s: %s", path, err)
-	} else {
-		idp, err := uuid.Parse(string(idb))
-		if err != nil {
-			return "", fmt.Errorf("Error parsing uuid in file %s: %s", path, err)
-		}
-		id = idp.String()
-	}
-	return id, nil
-}

distribution/config.go

@@ -18,6 +18,7 @@ import (
 	"github.com/docker/docker/pkg/system"
 	refstore "github.com/docker/docker/reference"
 	"github.com/docker/docker/registry"
+	"github.com/docker/libtrust"
 	"github.com/opencontainers/go-digest"
 	specs "github.com/opencontainers/image-spec/specs-go/v1"
 )
@@ -72,6 +73,9 @@ type ImagePushConfig struct {
 	ConfigMediaType string
 	// LayerStores (indexed by operating system) manages layers.
 	LayerStores map[string]PushLayerProvider
+	// TrustKey is the private key for legacy signatures. This is typically
+	// an ephemeral key, since these signatures are no longer verified.
+	TrustKey libtrust.PrivateKey
 	// UploadManager dispatches uploads.
 	UploadManager *xfer.LayerUploadManager
 }

distribution/push_v2.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"runtime"
 	"sort"
 	"strings"
 	"sync"
@@ -180,8 +181,26 @@ func (p *v2Pusher) pushV2Tag(ctx context.Context, ref reference.NamedTagged, id
 
 	putOptions := []distribution.ManifestServiceOption{distribution.WithTag(ref.Tag())}
 	if _, err = manSvc.Put(ctx, manifest, putOptions...); err != nil {
-		logrus.Warnf("failed to upload schema2 manifest: %v", err)
-		return err
+		if runtime.GOOS == "windows" || p.config.TrustKey == nil || p.config.RequireSchema2 {
+			logrus.Warnf("failed to upload schema2 manifest: %v", err)
+			return err
+		}
+
+		logrus.Warnf("failed to upload schema2 manifest: %v - falling back to schema1", err)
+
+		manifestRef, err := reference.WithTag(p.repo.Named(), ref.Tag())
+		if err != nil {
+			return err
+		}
+		builder = schema1.NewConfigManifestBuilder(p.repo.Blobs(ctx), p.config.TrustKey, manifestRef, imgConfig)
+		manifest, err = manifestFromBuilder(ctx, builder, descriptors)
+		if err != nil {
+			return err
+		}
+
+		if _, err = manSvc.Put(ctx, manifest, putOptions...); err != nil {
+			return err
+		}
 	}
 
 	var canonicalManifest []byte

integration-cli/docker_cli_daemon_test.go

@@ -18,7 +18,6 @@ import (
 	"path"
 	"path/filepath"
 	"regexp"
-	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -36,6 +35,7 @@ import (
 	"github.com/docker/docker/pkg/mount"
 	"github.com/docker/go-units"
 	"github.com/docker/libnetwork/iptables"
+	"github.com/docker/libtrust"
 	"github.com/go-check/check"
 	"github.com/kr/pty"
 	"golang.org/x/sys/unix"
@@ -551,23 +551,20 @@ func (s *DockerDaemonSuite) TestDaemonAllocatesListeningPort(c *check.C) {
 	}
 }
 
-func (s *DockerDaemonSuite) TestDaemonUUIDGeneration(c *check.C) {
-	dir := "/var/lib/docker"
-	if runtime.GOOS == "windows" {
-		dir = filepath.Join(os.Getenv("programdata"), "docker")
-	}
-	file := filepath.Join(dir, "engine_uuid")
-	os.Remove(file)
+func (s *DockerDaemonSuite) TestDaemonKeyGeneration(c *check.C) {
+	// TODO: skip or update for Windows daemon
+	os.Remove("/etc/docker/key.json")
 	s.d.Start(c)
 	s.d.Stop(c)
 
-	fi, err := os.Stat(file)
+	k, err := libtrust.LoadKeyFile("/etc/docker/key.json")
 	if err != nil {
-		c.Fatalf("Error opening uuid file")
+		c.Fatalf("Error opening key file")
 	}
-	// Test for uuid length
-	if fi.Size() != 36 {
-		c.Fatalf("Bad UUID size %d", fi.Size())
+	kid := k.KeyID()
+	// Test Key ID is a valid fingerprint (e.g. QQXN:JY5W:TBXI:MK3X:GX6P:PD5D:F56N:NHCS:LVRZ:JA46:R24J:XEFF)
+	if len(kid) != 59 {
+		c.Fatalf("Bad key ID: %s", kid)
 	}
 }
 

internal/test/fixtures/plugin/plugin.go

@@ -92,7 +92,7 @@ func CreateInRegistry(ctx context.Context, repo string, auth *types.AuthConfig,
 		return nil, nil
 	}
 
-	regService, err := registry.NewService(registry.ServiceOptions{})
+	regService, err := registry.NewService(registry.ServiceOptions{V2Only: true})
 	if err != nil {
 		return err
 	}

registry/config.go

@@ -19,11 +19,16 @@ type ServiceOptions struct {
 	AllowNondistributableArtifacts []string `json:"allow-nondistributable-artifacts,omitempty"`
 	Mirrors                        []string `json:"registry-mirrors,omitempty"`
 	InsecureRegistries             []string `json:"insecure-registries,omitempty"`
+
+	// 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 bool `json:"disable-legacy-registry,omitempty"`
 }
 
 // serviceConfig holds daemon configuration for the registry service.
 type serviceConfig struct {
 	registrytypes.ServiceConfig
+	V2Only bool
 }
 
 var (
@@ -71,6 +76,7 @@ func newServiceConfig(options ServiceOptions) (*serviceConfig, error) {
 			// Hack: Bypass setting the mirrors to IndexConfigs since they are going away
 			// and Mirrors are only for the official registry anyways.
 		},
+		V2Only: options.V2Only,
 	}
 	if err := config.LoadAllowNondistributableArtifacts(options.AllowNondistributableArtifacts); err != nil {
 		return nil, err

registry/service.go

@@ -309,5 +309,20 @@ func (s *DefaultService) LookupPushEndpoints(hostname string) (endpoints []APIEn
 }
 
 func (s *DefaultService) lookupEndpoints(hostname string) (endpoints []APIEndpoint, err error) {
-	return s.lookupV2Endpoints(hostname)
+	endpoints, err = s.lookupV2Endpoints(hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	if s.config.V2Only {
+		return endpoints, nil
+	}
+
+	legacyEndpoints, err := s.lookupV1Endpoints(hostname)
+	if err != nil {
+		return nil, err
+	}
+	endpoints = append(endpoints, legacyEndpoints...)
+
+	return endpoints, nil
 }