Update traefik dependencies (docker/docker and related) (#1823)

Update traefik dependencies (docker/docker and related) - Update dependencies - Fix compilation problems - Remove vdemeester/docker-events (in docker api now) - Remove `integration/vendor` - Use `testImport` - update some deps. - regenerate the lock from scratch (after a `glide cc`)
2017-07-06 16:28:13 +02:00 · 2017-07-06 16:28:13 +02:00 · b7daa2f3a4
commit b7daa2f3a4
parent 7d178f49b4
1301 changed files with 21476 additions and 150099 deletions
--- a/vendor/github.com/docker/distribution/registry/api/errcode/errors.go
+++ b/vendor/github.com/docker/distribution/registry/api/errcode/errors.go
@ -0,0 +1,267 @@
+package errcode
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+// ErrorCoder is the base interface for ErrorCode and Error allowing
+// users of each to just call ErrorCode to get the real ID of each
+type ErrorCoder interface {
+	ErrorCode() ErrorCode
+}
+
+// ErrorCode represents the error type. The errors are serialized via strings
+// and the integer format may change and should *never* be exported.
+type ErrorCode int
+
+var _ error = ErrorCode(0)
+
+// ErrorCode just returns itself
+func (ec ErrorCode) ErrorCode() ErrorCode {
+	return ec
+}
+
+// Error returns the ID/Value
+func (ec ErrorCode) Error() string {
+	// NOTE(stevvooe): Cannot use message here since it may have unpopulated args.
+	return strings.ToLower(strings.Replace(ec.String(), "_", " ", -1))
+}
+
+// Descriptor returns the descriptor for the error code.
+func (ec ErrorCode) Descriptor() ErrorDescriptor {
+	d, ok := errorCodeToDescriptors[ec]
+
+	if !ok {
+		return ErrorCodeUnknown.Descriptor()
+	}
+
+	return d
+}
+
+// String returns the canonical identifier for this error code.
+func (ec ErrorCode) String() string {
+	return ec.Descriptor().Value
+}
+
+// Message returned the human-readable error message for this error code.
+func (ec ErrorCode) Message() string {
+	return ec.Descriptor().Message
+}
+
+// MarshalText encodes the receiver into UTF-8-encoded text and returns the
+// result.
+func (ec ErrorCode) MarshalText() (text []byte, err error) {
+	return []byte(ec.String()), nil
+}
+
+// UnmarshalText decodes the form generated by MarshalText.
+func (ec *ErrorCode) UnmarshalText(text []byte) error {
+	desc, ok := idToDescriptors[string(text)]
+
+	if !ok {
+		desc = ErrorCodeUnknown.Descriptor()
+	}
+
+	*ec = desc.Code
+
+	return nil
+}
+
+// WithMessage creates a new Error struct based on the passed-in info and
+// overrides the Message property.
+func (ec ErrorCode) WithMessage(message string) Error {
+	return Error{
+		Code:    ec,
+		Message: message,
+	}
+}
+
+// WithDetail creates a new Error struct based on the passed-in info and
+// set the Detail property appropriately
+func (ec ErrorCode) WithDetail(detail interface{}) Error {
+	return Error{
+		Code:    ec,
+		Message: ec.Message(),
+	}.WithDetail(detail)
+}
+
+// WithArgs creates a new Error struct and sets the Args slice
+func (ec ErrorCode) WithArgs(args ...interface{}) Error {
+	return Error{
+		Code:    ec,
+		Message: ec.Message(),
+	}.WithArgs(args...)
+}
+
+// Error provides a wrapper around ErrorCode with extra Details provided.
+type Error struct {
+	Code    ErrorCode   `json:"code"`
+	Message string      `json:"message"`
+	Detail  interface{} `json:"detail,omitempty"`
+
+	// TODO(duglin): See if we need an "args" property so we can do the
+	// variable substitution right before showing the message to the user
+}
+
+var _ error = Error{}
+
+// ErrorCode returns the ID/Value of this Error
+func (e Error) ErrorCode() ErrorCode {
+	return e.Code
+}
+
+// Error returns a human readable representation of the error.
+func (e Error) Error() string {
+	return fmt.Sprintf("%s: %s", e.Code.Error(), e.Message)
+}
+
+// WithDetail will return a new Error, based on the current one, but with
+// some Detail info added
+func (e Error) WithDetail(detail interface{}) Error {
+	return Error{
+		Code:    e.Code,
+		Message: e.Message,
+		Detail:  detail,
+	}
+}
+
+// WithArgs uses the passed-in list of interface{} as the substitution
+// variables in the Error's Message string, but returns a new Error
+func (e Error) WithArgs(args ...interface{}) Error {
+	return Error{
+		Code:    e.Code,
+		Message: fmt.Sprintf(e.Code.Message(), args...),
+		Detail:  e.Detail,
+	}
+}
+
+// ErrorDescriptor provides relevant information about a given error code.
+type ErrorDescriptor struct {
+	// Code is the error code that this descriptor describes.
+	Code ErrorCode
+
+	// Value provides a unique, string key, often captilized with
+	// underscores, to identify the error code. This value is used as the
+	// keyed value when serializing api errors.
+	Value string
+
+	// Message is a short, human readable decription of the error condition
+	// included in API responses.
+	Message string
+
+	// Description provides a complete account of the errors purpose, suitable
+	// for use in documentation.
+	Description string
+
+	// HTTPStatusCode provides the http status code that is associated with
+	// this error condition.
+	HTTPStatusCode int
+}
+
+// ParseErrorCode returns the value by the string error code.
+// `ErrorCodeUnknown` will be returned if the error is not known.
+func ParseErrorCode(value string) ErrorCode {
+	ed, ok := idToDescriptors[value]
+	if ok {
+		return ed.Code
+	}
+
+	return ErrorCodeUnknown
+}
+
+// Errors provides the envelope for multiple errors and a few sugar methods
+// for use within the application.
+type Errors []error
+
+var _ error = Errors{}
+
+func (errs Errors) Error() string {
+	switch len(errs) {
+	case 0:
+		return "<nil>"
+	case 1:
+		return errs[0].Error()
+	default:
+		msg := "errors:\n"
+		for _, err := range errs {
+			msg += err.Error() + "\n"
+		}
+		return msg
+	}
+}
+
+// Len returns the current number of errors.
+func (errs Errors) Len() int {
+	return len(errs)
+}
+
+// MarshalJSON converts slice of error, ErrorCode or Error into a
+// slice of Error - then serializes
+func (errs Errors) MarshalJSON() ([]byte, error) {
+	var tmpErrs struct {
+		Errors []Error `json:"errors,omitempty"`
+	}
+
+	for _, daErr := range errs {
+		var err Error
+
+		switch daErr.(type) {
+		case ErrorCode:
+			err = daErr.(ErrorCode).WithDetail(nil)
+		case Error:
+			err = daErr.(Error)
+		default:
+			err = ErrorCodeUnknown.WithDetail(daErr)
+
+		}
+
+		// If the Error struct was setup and they forgot to set the
+		// Message field (meaning its "") then grab it from the ErrCode
+		msg := err.Message
+		if msg == "" {
+			msg = err.Code.Message()
+		}
+
+		tmpErrs.Errors = append(tmpErrs.Errors, Error{
+			Code:    err.Code,
+			Message: msg,
+			Detail:  err.Detail,
+		})
+	}
+
+	return json.Marshal(tmpErrs)
+}
+
+// UnmarshalJSON deserializes []Error and then converts it into slice of
+// Error or ErrorCode
+func (errs *Errors) UnmarshalJSON(data []byte) error {
+	var tmpErrs struct {
+		Errors []Error
+	}
+
+	if err := json.Unmarshal(data, &tmpErrs); err != nil {
+		return err
+	}
+
+	var newErrs Errors
+	for _, daErr := range tmpErrs.Errors {
+		// If Message is empty or exactly matches the Code's message string
+		// then just use the Code, no need for a full Error struct
+		if daErr.Detail == nil && (daErr.Message == "" || daErr.Message == daErr.Code.Message()) {
+			// Error's w/o details get converted to ErrorCode
+			newErrs = append(newErrs, daErr.Code)
+		} else {
+			// Error's w/ details are untouched
+			newErrs = append(newErrs, Error{
+				Code:    daErr.Code,
+				Message: daErr.Message,
+				Detail:  daErr.Detail,
+			})
+		}
+	}
+
+	*errs = newErrs
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/api/errcode/handler.go
+++ b/vendor/github.com/docker/distribution/registry/api/errcode/handler.go
@ -0,0 +1,44 @@
+package errcode
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+// ServeJSON attempts to serve the errcode in a JSON envelope. It marshals err
+// and sets the content-type header to 'application/json'. It will handle
+// ErrorCoder and Errors, and if necessary will create an envelope.
+func ServeJSON(w http.ResponseWriter, err error) error {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	var sc int
+
+	switch errs := err.(type) {
+	case Errors:
+		if len(errs) < 1 {
+			break
+		}
+
+		if err, ok := errs[0].(ErrorCoder); ok {
+			sc = err.ErrorCode().Descriptor().HTTPStatusCode
+		}
+	case ErrorCoder:
+		sc = errs.ErrorCode().Descriptor().HTTPStatusCode
+		err = Errors{err} // create an envelope.
+	default:
+		// We just have an unhandled error type, so just place in an envelope
+		// and move along.
+		err = Errors{err}
+	}
+
+	if sc == 0 {
+		sc = http.StatusInternalServerError
+	}
+
+	w.WriteHeader(sc)
+
+	if err := json.NewEncoder(w).Encode(err); err != nil {
+		return err
+	}
+
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/api/errcode/register.go
+++ b/vendor/github.com/docker/distribution/registry/api/errcode/register.go
@ -0,0 +1,138 @@
+package errcode
+
+import (
+	"fmt"
+	"net/http"
+	"sort"
+	"sync"
+)
+
+var (
+	errorCodeToDescriptors = map[ErrorCode]ErrorDescriptor{}
+	idToDescriptors        = map[string]ErrorDescriptor{}
+	groupToDescriptors     = map[string][]ErrorDescriptor{}
+)
+
+var (
+	// ErrorCodeUnknown is a generic error that can be used as a last
+	// resort if there is no situation-specific error message that can be used
+	ErrorCodeUnknown = Register("errcode", ErrorDescriptor{
+		Value:   "UNKNOWN",
+		Message: "unknown error",
+		Description: `Generic error returned when the error does not have an
+			                                            API classification.`,
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
+
+	// ErrorCodeUnsupported is returned when an operation is not supported.
+	ErrorCodeUnsupported = Register("errcode", ErrorDescriptor{
+		Value:   "UNSUPPORTED",
+		Message: "The operation is unsupported.",
+		Description: `The operation was unsupported due to a missing
+		implementation or invalid set of parameters.`,
+		HTTPStatusCode: http.StatusMethodNotAllowed,
+	})
+
+	// ErrorCodeUnauthorized is returned if a request requires
+	// authentication.
+	ErrorCodeUnauthorized = Register("errcode", ErrorDescriptor{
+		Value:   "UNAUTHORIZED",
+		Message: "authentication required",
+		Description: `The access controller was unable to authenticate
+		the client. Often this will be accompanied by a
+		Www-Authenticate HTTP response header indicating how to
+		authenticate.`,
+		HTTPStatusCode: http.StatusUnauthorized,
+	})
+
+	// ErrorCodeDenied is returned if a client does not have sufficient
+	// permission to perform an action.
+	ErrorCodeDenied = Register("errcode", ErrorDescriptor{
+		Value:   "DENIED",
+		Message: "requested access to the resource is denied",
+		Description: `The access controller denied access for the
+		operation on a resource.`,
+		HTTPStatusCode: http.StatusForbidden,
+	})
+
+	// ErrorCodeUnavailable provides a common error to report unavailability
+	// of a service or endpoint.
+	ErrorCodeUnavailable = Register("errcode", ErrorDescriptor{
+		Value:          "UNAVAILABLE",
+		Message:        "service unavailable",
+		Description:    "Returned when a service is not available",
+		HTTPStatusCode: http.StatusServiceUnavailable,
+	})
+
+	// ErrorCodeTooManyRequests is returned if a client attempts too many
+	// times to contact a service endpoint.
+	ErrorCodeTooManyRequests = Register("errcode", ErrorDescriptor{
+		Value:   "TOOMANYREQUESTS",
+		Message: "too many requests",
+		Description: `Returned when a client attempts to contact a
+		service too many times`,
+		HTTPStatusCode: http.StatusTooManyRequests,
+	})
+)
+
+var nextCode = 1000
+var registerLock sync.Mutex
+
+// Register will make the passed-in error known to the environment and
+// return a new ErrorCode
+func Register(group string, descriptor ErrorDescriptor) ErrorCode {
+	registerLock.Lock()
+	defer registerLock.Unlock()
+
+	descriptor.Code = ErrorCode(nextCode)
+
+	if _, ok := idToDescriptors[descriptor.Value]; ok {
+		panic(fmt.Sprintf("ErrorValue %q is already registered", descriptor.Value))
+	}
+	if _, ok := errorCodeToDescriptors[descriptor.Code]; ok {
+		panic(fmt.Sprintf("ErrorCode %v is already registered", descriptor.Code))
+	}
+
+	groupToDescriptors[group] = append(groupToDescriptors[group], descriptor)
+	errorCodeToDescriptors[descriptor.Code] = descriptor
+	idToDescriptors[descriptor.Value] = descriptor
+
+	nextCode++
+	return descriptor.Code
+}
+
+type byValue []ErrorDescriptor
+
+func (a byValue) Len() int           { return len(a) }
+func (a byValue) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byValue) Less(i, j int) bool { return a[i].Value < a[j].Value }
+
+// GetGroupNames returns the list of Error group names that are registered
+func GetGroupNames() []string {
+	keys := []string{}
+
+	for k := range groupToDescriptors {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// GetErrorCodeGroup returns the named group of error descriptors
+func GetErrorCodeGroup(name string) []ErrorDescriptor {
+	desc := groupToDescriptors[name]
+	sort.Sort(byValue(desc))
+	return desc
+}
+
+// GetErrorAllDescriptors returns a slice of all ErrorDescriptors that are
+// registered, irrespective of what group they're in
+func GetErrorAllDescriptors() []ErrorDescriptor {
+	result := []ErrorDescriptor{}
+
+	for _, group := range GetGroupNames() {
+		result = append(result, GetErrorCodeGroup(group)...)
+	}
+	sort.Sort(byValue(result))
+	return result
+}
--- a/vendor/github.com/docker/distribution/registry/api/v2/descriptors.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/descriptors.go
--- a/vendor/github.com/docker/distribution/registry/api/v2/doc.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/doc.go
@ -0,0 +1,9 @@
+// Package v2 describes routes, urls and the error codes used in the Docker
+// Registry JSON HTTP API V2. In addition to declarations, descriptors are
+// provided for routes and error codes that can be used for implementation and
+// automatically generating documentation.
+//
+// Definitions here are considered to be locked down for the V2 registry api.
+// Any changes must be considered carefully and should not proceed without a
+// change proposal in docker core.
+package v2
--- a/vendor/github.com/docker/distribution/registry/api/v2/errors.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/errors.go
@ -0,0 +1,136 @@
+package v2
+
+import (
+	"net/http"
+
+	"github.com/docker/distribution/registry/api/errcode"
+)
+
+const errGroup = "registry.api.v2"
+
+var (
+	// ErrorCodeDigestInvalid is returned when uploading a blob if the
+	// provided digest does not match the blob contents.
+	ErrorCodeDigestInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "DIGEST_INVALID",
+		Message: "provided digest did not match uploaded content",
+		Description: `When a blob is uploaded, the registry will check that
+		the content matches the digest provided by the client. The error may
+		include a detail structure with the key "digest", including the
+		invalid digest string. This error may also be returned when a manifest
+		includes an invalid layer digest.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeSizeInvalid is returned when uploading a blob if the provided
+	ErrorCodeSizeInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "SIZE_INVALID",
+		Message: "provided length did not match content length",
+		Description: `When a layer is uploaded, the provided size will be
+		checked against the uploaded content. If they do not match, this error
+		will be returned.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeNameInvalid is returned when the name in the manifest does not
+	// match the provided name.
+	ErrorCodeNameInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "NAME_INVALID",
+		Message: "invalid repository name",
+		Description: `Invalid repository name encountered either during
+		manifest validation or any API operation.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeTagInvalid is returned when the tag in the manifest does not
+	// match the provided tag.
+	ErrorCodeTagInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "TAG_INVALID",
+		Message: "manifest tag did not match URI",
+		Description: `During a manifest upload, if the tag in the manifest
+		does not match the uri tag, this error will be returned.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeNameUnknown when the repository name is not known.
+	ErrorCodeNameUnknown = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "NAME_UNKNOWN",
+		Message: "repository name not known to registry",
+		Description: `This is returned if the name used during an operation is
+		unknown to the registry.`,
+		HTTPStatusCode: http.StatusNotFound,
+	})
+
+	// ErrorCodeManifestUnknown returned when image manifest is unknown.
+	ErrorCodeManifestUnknown = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "MANIFEST_UNKNOWN",
+		Message: "manifest unknown",
+		Description: `This error is returned when the manifest, identified by
+		name and tag is unknown to the repository.`,
+		HTTPStatusCode: http.StatusNotFound,
+	})
+
+	// ErrorCodeManifestInvalid returned when an image manifest is invalid,
+	// typically during a PUT operation. This error encompasses all errors
+	// encountered during manifest validation that aren't signature errors.
+	ErrorCodeManifestInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "MANIFEST_INVALID",
+		Message: "manifest invalid",
+		Description: `During upload, manifests undergo several checks ensuring
+		validity. If those checks fail, this error may be returned, unless a
+		more specific error is included. The detail will contain information
+		the failed validation.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeManifestUnverified is returned when the manifest fails
+	// signature verification.
+	ErrorCodeManifestUnverified = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "MANIFEST_UNVERIFIED",
+		Message: "manifest failed signature verification",
+		Description: `During manifest upload, if the manifest fails signature
+		verification, this error will be returned.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeManifestBlobUnknown is returned when a manifest blob is
+	// unknown to the registry.
+	ErrorCodeManifestBlobUnknown = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "MANIFEST_BLOB_UNKNOWN",
+		Message: "blob unknown to registry",
+		Description: `This error may be returned when a manifest blob is 
+		unknown to the registry.`,
+		HTTPStatusCode: http.StatusBadRequest,
+	})
+
+	// ErrorCodeBlobUnknown is returned when a blob is unknown to the
+	// registry. This can happen when the manifest references a nonexistent
+	// layer or the result is not found by a blob fetch.
+	ErrorCodeBlobUnknown = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "BLOB_UNKNOWN",
+		Message: "blob unknown to registry",
+		Description: `This error may be returned when a blob is unknown to the
+		registry in a specified repository. This can be returned with a
+		standard get or if a manifest references an unknown layer during
+		upload.`,
+		HTTPStatusCode: http.StatusNotFound,
+	})
+
+	// ErrorCodeBlobUploadUnknown is returned when an upload is unknown.
+	ErrorCodeBlobUploadUnknown = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "BLOB_UPLOAD_UNKNOWN",
+		Message: "blob upload unknown to registry",
+		Description: `If a blob upload has been cancelled or was never
+		started, this error code may be returned.`,
+		HTTPStatusCode: http.StatusNotFound,
+	})
+
+	// ErrorCodeBlobUploadInvalid is returned when an upload is invalid.
+	ErrorCodeBlobUploadInvalid = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:   "BLOB_UPLOAD_INVALID",
+		Message: "blob upload invalid",
+		Description: `The blob upload encountered an error and can no
+		longer proceed.`,
+		HTTPStatusCode: http.StatusNotFound,
+	})
+)
--- a/vendor/github.com/docker/distribution/registry/api/v2/headerparser.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/headerparser.go
@ -0,0 +1,161 @@
+package v2
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode"
+)
+
+var (
+	// according to rfc7230
+	reToken            = regexp.MustCompile(`^[^"(),/:;<=>?@[\]{}[:space:][:cntrl:]]+`)
+	reQuotedValue      = regexp.MustCompile(`^[^\\"]+`)
+	reEscapedCharacter = regexp.MustCompile(`^[[:blank:][:graph:]]`)
+)
+
+// parseForwardedHeader is a benevolent parser of Forwarded header defined in rfc7239. The header contains
+// a comma-separated list of forwarding key-value pairs. Each list element is set by single proxy. The
+// function parses only the first element of the list, which is set by the very first proxy. It returns a map
+// of corresponding key-value pairs and an unparsed slice of the input string.
+//
+// Examples of Forwarded header values:
+//
+//  1. Forwarded: For=192.0.2.43; Proto=https,For="[2001:db8:cafe::17]",For=unknown
+//  2. Forwarded: for="192.0.2.43:443"; host="registry.example.org", for="10.10.05.40:80"
+//
+// The first will be parsed into {"for": "192.0.2.43", "proto": "https"} while the second into
+// {"for": "192.0.2.43:443", "host": "registry.example.org"}.
+func parseForwardedHeader(forwarded string) (map[string]string, string, error) {
+	// Following are states of forwarded header parser. Any state could transition to a failure.
+	const (
+		// terminating state; can transition to Parameter
+		stateElement = iota
+		// terminating state; can transition to KeyValueDelimiter
+		stateParameter
+		// can transition to Value
+		stateKeyValueDelimiter
+		// can transition to one of { QuotedValue, PairEnd }
+		stateValue
+		// can transition to one of { EscapedCharacter, PairEnd }
+		stateQuotedValue
+		// can transition to one of { QuotedValue }
+		stateEscapedCharacter
+		// terminating state; can transition to one of { Parameter, Element }
+		statePairEnd
+	)
+
+	var (
+		parameter string
+		value     string
+		parse     = forwarded[:]
+		res       = map[string]string{}
+		state     = stateElement
+	)
+
+Loop:
+	for {
+		// skip spaces unless in quoted value
+		if state != stateQuotedValue && state != stateEscapedCharacter {
+			parse = strings.TrimLeftFunc(parse, unicode.IsSpace)
+		}
+
+		if len(parse) == 0 {
+			if state != stateElement && state != statePairEnd && state != stateParameter {
+				return nil, parse, fmt.Errorf("unexpected end of input")
+			}
+			// terminating
+			break
+		}
+
+		switch state {
+		// terminate at list element delimiter
+		case stateElement:
+			if parse[0] == ',' {
+				parse = parse[1:]
+				break Loop
+			}
+			state = stateParameter
+
+		// parse parameter (the key of key-value pair)
+		case stateParameter:
+			match := reToken.FindString(parse)
+			if len(match) == 0 {
+				return nil, parse, fmt.Errorf("failed to parse token at position %d", len(forwarded)-len(parse))
+			}
+			parameter = strings.ToLower(match)
+			parse = parse[len(match):]
+			state = stateKeyValueDelimiter
+
+		// parse '='
+		case stateKeyValueDelimiter:
+			if parse[0] != '=' {
+				return nil, parse, fmt.Errorf("expected '=', not '%c' at position %d", parse[0], len(forwarded)-len(parse))
+			}
+			parse = parse[1:]
+			state = stateValue
+
+		// parse value or quoted value
+		case stateValue:
+			if parse[0] == '"' {
+				parse = parse[1:]
+				state = stateQuotedValue
+			} else {
+				value = reToken.FindString(parse)
+				if len(value) == 0 {
+					return nil, parse, fmt.Errorf("failed to parse value at position %d", len(forwarded)-len(parse))
+				}
+				if _, exists := res[parameter]; exists {
+					return nil, parse, fmt.Errorf("duplicate parameter %q at position %d", parameter, len(forwarded)-len(parse))
+				}
+				res[parameter] = value
+				parse = parse[len(value):]
+				value = ""
+				state = statePairEnd
+			}
+
+		// parse a part of quoted value until the first backslash
+		case stateQuotedValue:
+			match := reQuotedValue.FindString(parse)
+			value += match
+			parse = parse[len(match):]
+			switch {
+			case len(parse) == 0:
+				return nil, parse, fmt.Errorf("unterminated quoted string")
+			case parse[0] == '"':
+				res[parameter] = value
+				value = ""
+				parse = parse[1:]
+				state = statePairEnd
+			case parse[0] == '\\':
+				parse = parse[1:]
+				state = stateEscapedCharacter
+			}
+
+		// parse escaped character in a quoted string, ignore the backslash
+		// transition back to QuotedValue state
+		case stateEscapedCharacter:
+			c := reEscapedCharacter.FindString(parse)
+			if len(c) == 0 {
+				return nil, parse, fmt.Errorf("invalid escape sequence at position %d", len(forwarded)-len(parse)-1)
+			}
+			value += c
+			parse = parse[1:]
+			state = stateQuotedValue
+
+		// expect either a new key-value pair, new list or end of input
+		case statePairEnd:
+			switch parse[0] {
+			case ';':
+				parse = parse[1:]
+				state = stateParameter
+			case ',':
+				state = stateElement
+			default:
+				return nil, parse, fmt.Errorf("expected ',' or ';', not %c at position %d", parse[0], len(forwarded)-len(parse))
+			}
+		}
+	}
+
+	return res, parse, nil
+}
--- a/vendor/github.com/docker/distribution/registry/api/v2/routes.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/routes.go
@ -0,0 +1,49 @@
+package v2
+
+import "github.com/gorilla/mux"
+
+// The following are definitions of the name under which all V2 routes are
+// registered. These symbols can be used to look up a route based on the name.
+const (
+	RouteNameBase            = "base"
+	RouteNameManifest        = "manifest"
+	RouteNameTags            = "tags"
+	RouteNameBlob            = "blob"
+	RouteNameBlobUpload      = "blob-upload"
+	RouteNameBlobUploadChunk = "blob-upload-chunk"
+	RouteNameCatalog         = "catalog"
+)
+
+var allEndpoints = []string{
+	RouteNameManifest,
+	RouteNameCatalog,
+	RouteNameTags,
+	RouteNameBlob,
+	RouteNameBlobUpload,
+	RouteNameBlobUploadChunk,
+}
+
+// Router builds a gorilla router with named routes for the various API
+// methods. This can be used directly by both server implementations and
+// clients.
+func Router() *mux.Router {
+	return RouterWithPrefix("")
+}
+
+// RouterWithPrefix builds a gorilla router with a configured prefix
+// on all routes.
+func RouterWithPrefix(prefix string) *mux.Router {
+	rootRouter := mux.NewRouter()
+	router := rootRouter
+	if prefix != "" {
+		router = router.PathPrefix(prefix).Subrouter()
+	}
+
+	router.StrictSlash(true)
+
+	for _, descriptor := range routeDescriptors {
+		router.Path(descriptor.Path).Name(descriptor.Name)
+	}
+
+	return rootRouter
+}
--- a/vendor/github.com/docker/distribution/registry/api/v2/urls.go
+++ b/vendor/github.com/docker/distribution/registry/api/v2/urls.go
@ -0,0 +1,314 @@
+package v2
+
+import (
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/docker/distribution/reference"
+	"github.com/gorilla/mux"
+)
+
+// URLBuilder creates registry API urls from a single base endpoint. It can be
+// used to create urls for use in a registry client or server.
+//
+// All urls will be created from the given base, including the api version.
+// For example, if a root of "/foo/" is provided, urls generated will be fall
+// under "/foo/v2/...". Most application will only provide a schema, host and
+// port, such as "https://localhost:5000/".
+type URLBuilder struct {
+	root     *url.URL // url root (ie http://localhost/)
+	router   *mux.Router
+	relative bool
+}
+
+// NewURLBuilder creates a URLBuilder with provided root url object.
+func NewURLBuilder(root *url.URL, relative bool) *URLBuilder {
+	return &URLBuilder{
+		root:     root,
+		router:   Router(),
+		relative: relative,
+	}
+}
+
+// NewURLBuilderFromString workes identically to NewURLBuilder except it takes
+// a string argument for the root, returning an error if it is not a valid
+// url.
+func NewURLBuilderFromString(root string, relative bool) (*URLBuilder, error) {
+	u, err := url.Parse(root)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewURLBuilder(u, relative), nil
+}
+
+// NewURLBuilderFromRequest uses information from an *http.Request to
+// construct the root url.
+func NewURLBuilderFromRequest(r *http.Request, relative bool) *URLBuilder {
+	var scheme string
+
+	forwardedProto := r.Header.Get("X-Forwarded-Proto")
+	// TODO: log the error
+	forwardedHeader, _, _ := parseForwardedHeader(r.Header.Get("Forwarded"))
+
+	switch {
+	case len(forwardedProto) > 0:
+		scheme = forwardedProto
+	case len(forwardedHeader["proto"]) > 0:
+		scheme = forwardedHeader["proto"]
+	case r.TLS != nil:
+		scheme = "https"
+	case len(r.URL.Scheme) > 0:
+		scheme = r.URL.Scheme
+	default:
+		scheme = "http"
+	}
+
+	host := r.Host
+
+	if forwardedHost := r.Header.Get("X-Forwarded-Host"); len(forwardedHost) > 0 {
+		// According to the Apache mod_proxy docs, X-Forwarded-Host can be a
+		// comma-separated list of hosts, to which each proxy appends the
+		// requested host. We want to grab the first from this comma-separated
+		// list.
+		hosts := strings.SplitN(forwardedHost, ",", 2)
+		host = strings.TrimSpace(hosts[0])
+	} else if addr, exists := forwardedHeader["for"]; exists {
+		host = addr
+	} else if h, exists := forwardedHeader["host"]; exists {
+		host = h
+	}
+
+	portLessHost, port := host, ""
+	if !isIPv6Address(portLessHost) {
+		// with go 1.6, this would treat the last part of IPv6 address as a port
+		portLessHost, port, _ = net.SplitHostPort(host)
+	}
+	if forwardedPort := r.Header.Get("X-Forwarded-Port"); len(port) == 0 && len(forwardedPort) > 0 {
+		ports := strings.SplitN(forwardedPort, ",", 2)
+		forwardedPort = strings.TrimSpace(ports[0])
+		if _, err := strconv.ParseInt(forwardedPort, 10, 32); err == nil {
+			port = forwardedPort
+		}
+	}
+
+	if len(portLessHost) > 0 {
+		host = portLessHost
+	}
+	if len(port) > 0 {
+		// remove enclosing brackets of ipv6 address otherwise they will be duplicated
+		if len(host) > 1 && host[0] == '[' && host[len(host)-1] == ']' {
+			host = host[1 : len(host)-1]
+		}
+		// JoinHostPort properly encloses ipv6 addresses in square brackets
+		host = net.JoinHostPort(host, port)
+	} else if isIPv6Address(host) && host[0] != '[' {
+		// ipv6 needs to be enclosed in square brackets in urls
+		host = "[" + host + "]"
+	}
+
+	basePath := routeDescriptorsMap[RouteNameBase].Path
+
+	requestPath := r.URL.Path
+	index := strings.Index(requestPath, basePath)
+
+	u := &url.URL{
+		Scheme: scheme,
+		Host:   host,
+	}
+
+	if index > 0 {
+		// N.B. index+1 is important because we want to include the trailing /
+		u.Path = requestPath[0 : index+1]
+	}
+
+	return NewURLBuilder(u, relative)
+}
+
+// BuildBaseURL constructs a base url for the API, typically just "/v2/".
+func (ub *URLBuilder) BuildBaseURL() (string, error) {
+	route := ub.cloneRoute(RouteNameBase)
+
+	baseURL, err := route.URL()
+	if err != nil {
+		return "", err
+	}
+
+	return baseURL.String(), nil
+}
+
+// BuildCatalogURL constructs a url get a catalog of repositories
+func (ub *URLBuilder) BuildCatalogURL(values ...url.Values) (string, error) {
+	route := ub.cloneRoute(RouteNameCatalog)
+
+	catalogURL, err := route.URL()
+	if err != nil {
+		return "", err
+	}
+
+	return appendValuesURL(catalogURL, values...).String(), nil
+}
+
+// BuildTagsURL constructs a url to list the tags in the named repository.
+func (ub *URLBuilder) BuildTagsURL(name reference.Named) (string, error) {
+	route := ub.cloneRoute(RouteNameTags)
+
+	tagsURL, err := route.URL("name", name.Name())
+	if err != nil {
+		return "", err
+	}
+
+	return tagsURL.String(), nil
+}
+
+// BuildManifestURL constructs a url for the manifest identified by name and
+// reference. The argument reference may be either a tag or digest.
+func (ub *URLBuilder) BuildManifestURL(ref reference.Named) (string, error) {
+	route := ub.cloneRoute(RouteNameManifest)
+
+	tagOrDigest := ""
+	switch v := ref.(type) {
+	case reference.Tagged:
+		tagOrDigest = v.Tag()
+	case reference.Digested:
+		tagOrDigest = v.Digest().String()
+	}
+
+	manifestURL, err := route.URL("name", ref.Name(), "reference", tagOrDigest)
+	if err != nil {
+		return "", err
+	}
+
+	return manifestURL.String(), nil
+}
+
+// BuildBlobURL constructs the url for the blob identified by name and dgst.
+func (ub *URLBuilder) BuildBlobURL(ref reference.Canonical) (string, error) {
+	route := ub.cloneRoute(RouteNameBlob)
+
+	layerURL, err := route.URL("name", ref.Name(), "digest", ref.Digest().String())
+	if err != nil {
+		return "", err
+	}
+
+	return layerURL.String(), nil
+}
+
+// BuildBlobUploadURL constructs a url to begin a blob upload in the
+// repository identified by name.
+func (ub *URLBuilder) BuildBlobUploadURL(name reference.Named, values ...url.Values) (string, error) {
+	route := ub.cloneRoute(RouteNameBlobUpload)
+
+	uploadURL, err := route.URL("name", name.Name())
+	if err != nil {
+		return "", err
+	}
+
+	return appendValuesURL(uploadURL, values...).String(), nil
+}
+
+// BuildBlobUploadChunkURL constructs a url for the upload identified by uuid,
+// including any url values. This should generally not be used by clients, as
+// this url is provided by server implementations during the blob upload
+// process.
+func (ub *URLBuilder) BuildBlobUploadChunkURL(name reference.Named, uuid string, values ...url.Values) (string, error) {
+	route := ub.cloneRoute(RouteNameBlobUploadChunk)
+
+	uploadURL, err := route.URL("name", name.Name(), "uuid", uuid)
+	if err != nil {
+		return "", err
+	}
+
+	return appendValuesURL(uploadURL, values...).String(), nil
+}
+
+// clondedRoute returns a clone of the named route from the router. Routes
+// must be cloned to avoid modifying them during url generation.
+func (ub *URLBuilder) cloneRoute(name string) clonedRoute {
+	route := new(mux.Route)
+	root := new(url.URL)
+
+	*route = *ub.router.GetRoute(name) // clone the route
+	*root = *ub.root
+
+	return clonedRoute{Route: route, root: root, relative: ub.relative}
+}
+
+type clonedRoute struct {
+	*mux.Route
+	root     *url.URL
+	relative bool
+}
+
+func (cr clonedRoute) URL(pairs ...string) (*url.URL, error) {
+	routeURL, err := cr.Route.URL(pairs...)
+	if err != nil {
+		return nil, err
+	}
+
+	if cr.relative {
+		return routeURL, nil
+	}
+
+	if routeURL.Scheme == "" && routeURL.User == nil && routeURL.Host == "" {
+		routeURL.Path = routeURL.Path[1:]
+	}
+
+	url := cr.root.ResolveReference(routeURL)
+	url.Scheme = cr.root.Scheme
+	return url, nil
+}
+
+// appendValuesURL appends the parameters to the url.
+func appendValuesURL(u *url.URL, values ...url.Values) *url.URL {
+	merged := u.Query()
+
+	for _, v := range values {
+		for k, vv := range v {
+			merged[k] = append(merged[k], vv...)
+		}
+	}
+
+	u.RawQuery = merged.Encode()
+	return u
+}
+
+// appendValues appends the parameters to the url. Panics if the string is not
+// a url.
+func appendValues(u string, values ...url.Values) string {
+	up, err := url.Parse(u)
+
+	if err != nil {
+		panic(err) // should never happen
+	}
+
+	return appendValuesURL(up, values...).String()
+}
+
+// isIPv6Address returns true if given string is a valid IPv6 address. No port is allowed. The address may be
+// enclosed in square brackets.
+func isIPv6Address(host string) bool {
+	if len(host) > 1 && host[0] == '[' && host[len(host)-1] == ']' {
+		host = host[1 : len(host)-1]
+	}
+	// The IPv6 scoped addressing zone identifier starts after the last percent sign.
+	if i := strings.LastIndexByte(host, '%'); i > 0 {
+		host = host[:i]
+	}
+	ip := net.ParseIP(host)
+	if ip == nil {
+		return false
+	}
+	if ip.To16() == nil {
+		return false
+	}
+	if ip.To4() == nil {
+		return true
+	}
+	// dot can be present in ipv4-mapped address, it needs to come after a colon though
+	i := strings.IndexAny(host, ":.")
+	return i >= 0 && host[i] == ':'
+}
--- a/vendor/github.com/docker/distribution/registry/client/auth/api_version.go
+++ b/vendor/github.com/docker/distribution/registry/client/auth/api_version.go
@ -0,0 +1,58 @@
+package auth
+
+import (
+	"net/http"
+	"strings"
+)
+
+// APIVersion represents a version of an API including its
+// type and version number.
+type APIVersion struct {
+	// Type refers to the name of a specific API specification
+	// such as "registry"
+	Type string
+
+	// Version is the version of the API specification implemented,
+	// This may omit the revision number and only include
+	// the major and minor version, such as "2.0"
+	Version string
+}
+
+// String returns the string formatted API Version
+func (v APIVersion) String() string {
+	return v.Type + "/" + v.Version
+}
+
+// APIVersions gets the API versions out of an HTTP response using the provided
+// version header as the key for the HTTP header.
+func APIVersions(resp *http.Response, versionHeader string) []APIVersion {
+	versions := []APIVersion{}
+	if versionHeader != "" {
+		for _, supportedVersions := range resp.Header[http.CanonicalHeaderKey(versionHeader)] {
+			for _, version := range strings.Fields(supportedVersions) {
+				versions = append(versions, ParseAPIVersion(version))
+			}
+		}
+	}
+	return versions
+}
+
+// ParseAPIVersion parses an API version string into an APIVersion
+// Format (Expected, not enforced):
+// API version string = <API type> '/' <API version>
+// API type = [a-z][a-z0-9]*
+// API version = [0-9]+(\.[0-9]+)?
+// TODO(dmcgowan): Enforce format, add error condition, remove unknown type
+func ParseAPIVersion(versionStr string) APIVersion {
+	idx := strings.IndexRune(versionStr, '/')
+	if idx == -1 {
+		return APIVersion{
+			Type:    "unknown",
+			Version: versionStr,
+		}
+	}
+	return APIVersion{
+		Type:    strings.ToLower(versionStr[:idx]),
+		Version: versionStr[idx+1:],
+	}
+}
--- a/vendor/github.com/docker/distribution/registry/client/auth/challenge/addr.go
+++ b/vendor/github.com/docker/distribution/registry/client/auth/challenge/addr.go
@ -0,0 +1,27 @@
+package challenge
+
+import (
+	"net/url"
+	"strings"
+)
+
+// FROM: https://golang.org/src/net/http/http.go
+// Given a string of the form "host", "host:port", or "[ipv6::address]:port",
+// return true if the string includes a port.
+func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }
+
+// FROM: http://golang.org/src/net/http/transport.go
+var portMap = map[string]string{
+	"http":  "80",
+	"https": "443",
+}
+
+// canonicalAddr returns url.Host but always with a ":port" suffix
+// FROM: http://golang.org/src/net/http/transport.go
+func canonicalAddr(url *url.URL) string {
+	addr := url.Host
+	if !hasPort(addr) {
+		return addr + ":" + portMap[url.Scheme]
+	}
+	return addr
+}
--- a/vendor/github.com/docker/distribution/registry/client/auth/challenge/authchallenge.go
+++ b/vendor/github.com/docker/distribution/registry/client/auth/challenge/authchallenge.go
@ -0,0 +1,237 @@
+package challenge
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+)
+
+// Challenge carries information from a WWW-Authenticate response header.
+// See RFC 2617.
+type Challenge struct {
+	// Scheme is the auth-scheme according to RFC 2617
+	Scheme string
+
+	// Parameters are the auth-params according to RFC 2617
+	Parameters map[string]string
+}
+
+// Manager manages the challenges for endpoints.
+// The challenges are pulled out of HTTP responses. Only
+// responses which expect challenges should be added to
+// the manager, since a non-unauthorized request will be
+// viewed as not requiring challenges.
+type Manager interface {
+	// GetChallenges returns the challenges for the given
+	// endpoint URL.
+	GetChallenges(endpoint url.URL) ([]Challenge, error)
+
+	// AddResponse adds the response to the challenge
+	// manager. The challenges will be parsed out of
+	// the WWW-Authenicate headers and added to the
+	// URL which was produced the response. If the
+	// response was authorized, any challenges for the
+	// endpoint will be cleared.
+	AddResponse(resp *http.Response) error
+}
+
+// NewSimpleManager returns an instance of
+// Manger which only maps endpoints to challenges
+// based on the responses which have been added the
+// manager. The simple manager will make no attempt to
+// perform requests on the endpoints or cache the responses
+// to a backend.
+func NewSimpleManager() Manager {
+	return &simpleManager{
+		Challanges: make(map[string][]Challenge),
+	}
+}
+
+type simpleManager struct {
+	sync.RWMutex
+	Challanges map[string][]Challenge
+}
+
+func normalizeURL(endpoint *url.URL) {
+	endpoint.Host = strings.ToLower(endpoint.Host)
+	endpoint.Host = canonicalAddr(endpoint)
+}
+
+func (m *simpleManager) GetChallenges(endpoint url.URL) ([]Challenge, error) {
+	normalizeURL(&endpoint)
+
+	m.RLock()
+	defer m.RUnlock()
+	challenges := m.Challanges[endpoint.String()]
+	return challenges, nil
+}
+
+func (m *simpleManager) AddResponse(resp *http.Response) error {
+	challenges := ResponseChallenges(resp)
+	if resp.Request == nil {
+		return fmt.Errorf("missing request reference")
+	}
+	urlCopy := url.URL{
+		Path:   resp.Request.URL.Path,
+		Host:   resp.Request.URL.Host,
+		Scheme: resp.Request.URL.Scheme,
+	}
+	normalizeURL(&urlCopy)
+
+	m.Lock()
+	defer m.Unlock()
+	m.Challanges[urlCopy.String()] = challenges
+	return nil
+}
+
+// Octet types from RFC 2616.
+type octetType byte
+
+var octetTypes [256]octetType
+
+const (
+	isToken octetType = 1 << iota
+	isSpace
+)
+
+func init() {
+	// OCTET      = <any 8-bit sequence of data>
+	// CHAR       = <any US-ASCII character (octets 0 - 127)>
+	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+	// CR         = <US-ASCII CR, carriage return (13)>
+	// LF         = <US-ASCII LF, linefeed (10)>
+	// SP         = <US-ASCII SP, space (32)>
+	// HT         = <US-ASCII HT, horizontal-tab (9)>
+	// <">        = <US-ASCII double-quote mark (34)>
+	// CRLF       = CR LF
+	// LWS        = [CRLF] 1*( SP | HT )
+	// TEXT       = <any OCTET except CTLs, but including LWS>
+	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
+	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
+	// token      = 1*<any CHAR except CTLs or separators>
+	// qdtext     = <any TEXT except <">>
+
+	for c := 0; c < 256; c++ {
+		var t octetType
+		isCtl := c <= 31 || c == 127
+		isChar := 0 <= c && c <= 127
+		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
+		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+			t |= isSpace
+		}
+		if isChar && !isCtl && !isSeparator {
+			t |= isToken
+		}
+		octetTypes[c] = t
+	}
+}
+
+// ResponseChallenges returns a list of authorization challenges
+// for the given http Response. Challenges are only checked if
+// the response status code was a 401.
+func ResponseChallenges(resp *http.Response) []Challenge {
+	if resp.StatusCode == http.StatusUnauthorized {
+		// Parse the WWW-Authenticate Header and store the challenges
+		// on this endpoint object.
+		return parseAuthHeader(resp.Header)
+	}
+
+	return nil
+}
+
+func parseAuthHeader(header http.Header) []Challenge {
+	challenges := []Challenge{}
+	for _, h := range header[http.CanonicalHeaderKey("WWW-Authenticate")] {
+		v, p := parseValueAndParams(h)
+		if v != "" {
+			challenges = append(challenges, Challenge{Scheme: v, Parameters: p})
+		}
+	}
+	return challenges
+}
+
+func parseValueAndParams(header string) (value string, params map[string]string) {
+	params = make(map[string]string)
+	value, s := expectToken(header)
+	if value == "" {
+		return
+	}
+	value = strings.ToLower(value)
+	s = "," + skipSpace(s)
+	for strings.HasPrefix(s, ",") {
+		var pkey string
+		pkey, s = expectToken(skipSpace(s[1:]))
+		if pkey == "" {
+			return
+		}
+		if !strings.HasPrefix(s, "=") {
+			return
+		}
+		var pvalue string
+		pvalue, s = expectTokenOrQuoted(s[1:])
+		if pvalue == "" {
+			return
+		}
+		pkey = strings.ToLower(pkey)
+		params[pkey] = pvalue
+		s = skipSpace(s)
+	}
+	return
+}
+
+func skipSpace(s string) (rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isSpace == 0 {
+			break
+		}
+	}
+	return s[i:]
+}
+
+func expectToken(s string) (token, rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isToken == 0 {
+			break
+		}
+	}
+	return s[:i], s[i:]
+}
+
+func expectTokenOrQuoted(s string) (value string, rest string) {
+	if !strings.HasPrefix(s, "\"") {
+		return expectToken(s)
+	}
+	s = s[1:]
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '"':
+			return s[:i], s[i+1:]
+		case '\\':
+			p := make([]byte, len(s)-1)
+			j := copy(p, s[:i])
+			escape := true
+			for i = i + 1; i < len(s); i++ {
+				b := s[i]
+				switch {
+				case escape:
+					escape = false
+					p[j] = b
+					j++
+				case b == '\\':
+					escape = true
+				case b == '"':
+					return string(p[:j]), s[i+1:]
+				default:
+					p[j] = b
+					j++
+				}
+			}
+			return "", ""
+		}
+	}
+	return "", ""
+}
--- a/vendor/github.com/docker/distribution/registry/client/auth/session.go
+++ b/vendor/github.com/docker/distribution/registry/client/auth/session.go
@ -0,0 +1,505 @@
+package auth
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/distribution/registry/client"
+	"github.com/docker/distribution/registry/client/auth/challenge"
+	"github.com/docker/distribution/registry/client/transport"
+)
+
+var (
+	// ErrNoBasicAuthCredentials is returned if a request can't be authorized with
+	// basic auth due to lack of credentials.
+	ErrNoBasicAuthCredentials = errors.New("no basic auth credentials")
+
+	// ErrNoToken is returned if a request is successful but the body does not
+	// contain an authorization token.
+	ErrNoToken = errors.New("authorization server did not include a token in the response")
+)
+
+const defaultClientID = "registry-client"
+
+// AuthenticationHandler is an interface for authorizing a request from
+// params from a "WWW-Authenicate" header for a single scheme.
+type AuthenticationHandler interface {
+	// Scheme returns the scheme as expected from the "WWW-Authenicate" header.
+	Scheme() string
+
+	// AuthorizeRequest adds the authorization header to a request (if needed)
+	// using the parameters from "WWW-Authenticate" method. The parameters
+	// values depend on the scheme.
+	AuthorizeRequest(req *http.Request, params map[string]string) error
+}
+
+// CredentialStore is an interface for getting credentials for
+// a given URL
+type CredentialStore interface {
+	// Basic returns basic auth for the given URL
+	Basic(*url.URL) (string, string)
+
+	// RefreshToken returns a refresh token for the
+	// given URL and service
+	RefreshToken(*url.URL, string) string
+
+	// SetRefreshToken sets the refresh token if none
+	// is provided for the given url and service
+	SetRefreshToken(realm *url.URL, service, token string)
+}
+
+// NewAuthorizer creates an authorizer which can handle multiple authentication
+// schemes. The handlers are tried in order, the higher priority authentication
+// methods should be first. The challengeMap holds a list of challenges for
+// a given root API endpoint (for example "https://registry-1.docker.io/v2/").
+func NewAuthorizer(manager challenge.Manager, handlers ...AuthenticationHandler) transport.RequestModifier {
+	return &endpointAuthorizer{
+		challenges: manager,
+		handlers:   handlers,
+	}
+}
+
+type endpointAuthorizer struct {
+	challenges challenge.Manager
+	handlers   []AuthenticationHandler
+	transport  http.RoundTripper
+}
+
+func (ea *endpointAuthorizer) ModifyRequest(req *http.Request) error {
+	pingPath := req.URL.Path
+	if v2Root := strings.Index(req.URL.Path, "/v2/"); v2Root != -1 {
+		pingPath = pingPath[:v2Root+4]
+	} else if v1Root := strings.Index(req.URL.Path, "/v1/"); v1Root != -1 {
+		pingPath = pingPath[:v1Root] + "/v2/"
+	} else {
+		return nil
+	}
+
+	ping := url.URL{
+		Host:   req.URL.Host,
+		Scheme: req.URL.Scheme,
+		Path:   pingPath,
+	}
+
+	challenges, err := ea.challenges.GetChallenges(ping)
+	if err != nil {
+		return err
+	}
+
+	if len(challenges) > 0 {
+		for _, handler := range ea.handlers {
+			for _, c := range challenges {
+				if c.Scheme != handler.Scheme() {
+					continue
+				}
+				if err := handler.AuthorizeRequest(req, c.Parameters); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+// This is the minimum duration a token can last (in seconds).
+// A token must not live less than 60 seconds because older versions
+// of the Docker client didn't read their expiration from the token
+// response and assumed 60 seconds.  So to remain compatible with
+// those implementations, a token must live at least this long.
+const minimumTokenLifetimeSeconds = 60
+
+// Private interface for time used by this package to enable tests to provide their own implementation.
+type clock interface {
+	Now() time.Time
+}
+
+type tokenHandler struct {
+	header    http.Header
+	creds     CredentialStore
+	transport http.RoundTripper
+	clock     clock
+
+	offlineAccess bool
+	forceOAuth    bool
+	clientID      string
+	scopes        []Scope
+
+	tokenLock       sync.Mutex
+	tokenCache      string
+	tokenExpiration time.Time
+}
+
+// Scope is a type which is serializable to a string
+// using the allow scope grammar.
+type Scope interface {
+	String() string
+}
+
+// RepositoryScope represents a token scope for access
+// to a repository.
+type RepositoryScope struct {
+	Repository string
+	Class      string
+	Actions    []string
+}
+
+// String returns the string representation of the repository
+// using the scope grammar
+func (rs RepositoryScope) String() string {
+	repoType := "repository"
+	// Keep existing format for image class to maintain backwards compatibility
+	// with authorization servers which do not support the expanded grammar.
+	if rs.Class != "" && rs.Class != "image" {
+		repoType = fmt.Sprintf("%s(%s)", repoType, rs.Class)
+	}
+	return fmt.Sprintf("%s:%s:%s", repoType, rs.Repository, strings.Join(rs.Actions, ","))
+}
+
+// RegistryScope represents a token scope for access
+// to resources in the registry.
+type RegistryScope struct {
+	Name    string
+	Actions []string
+}
+
+// String returns the string representation of the user
+// using the scope grammar
+func (rs RegistryScope) String() string {
+	return fmt.Sprintf("registry:%s:%s", rs.Name, strings.Join(rs.Actions, ","))
+}
+
+// TokenHandlerOptions is used to configure a new token handler
+type TokenHandlerOptions struct {
+	Transport   http.RoundTripper
+	Credentials CredentialStore
+
+	OfflineAccess bool
+	ForceOAuth    bool
+	ClientID      string
+	Scopes        []Scope
+}
+
+// An implementation of clock for providing real time data.
+type realClock struct{}
+
+// Now implements clock
+func (realClock) Now() time.Time { return time.Now() }
+
+// NewTokenHandler creates a new AuthenicationHandler which supports
+// fetching tokens from a remote token server.
+func NewTokenHandler(transport http.RoundTripper, creds CredentialStore, scope string, actions ...string) AuthenticationHandler {
+	// Create options...
+	return NewTokenHandlerWithOptions(TokenHandlerOptions{
+		Transport:   transport,
+		Credentials: creds,
+		Scopes: []Scope{
+			RepositoryScope{
+				Repository: scope,
+				Actions:    actions,
+			},
+		},
+	})
+}
+
+// NewTokenHandlerWithOptions creates a new token handler using the provided
+// options structure.
+func NewTokenHandlerWithOptions(options TokenHandlerOptions) AuthenticationHandler {
+	handler := &tokenHandler{
+		transport:     options.Transport,
+		creds:         options.Credentials,
+		offlineAccess: options.OfflineAccess,
+		forceOAuth:    options.ForceOAuth,
+		clientID:      options.ClientID,
+		scopes:        options.Scopes,
+		clock:         realClock{},
+	}
+
+	return handler
+}
+
+func (th *tokenHandler) client() *http.Client {
+	return &http.Client{
+		Transport: th.transport,
+		Timeout:   15 * time.Second,
+	}
+}
+
+func (th *tokenHandler) Scheme() string {
+	return "bearer"
+}
+
+func (th *tokenHandler) AuthorizeRequest(req *http.Request, params map[string]string) error {
+	var additionalScopes []string
+	if fromParam := req.URL.Query().Get("from"); fromParam != "" {
+		additionalScopes = append(additionalScopes, RepositoryScope{
+			Repository: fromParam,
+			Actions:    []string{"pull"},
+		}.String())
+	}
+
+	token, err := th.getToken(params, additionalScopes...)
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+
+	return nil
+}
+
+func (th *tokenHandler) getToken(params map[string]string, additionalScopes ...string) (string, error) {
+	th.tokenLock.Lock()
+	defer th.tokenLock.Unlock()
+	scopes := make([]string, 0, len(th.scopes)+len(additionalScopes))
+	for _, scope := range th.scopes {
+		scopes = append(scopes, scope.String())
+	}
+	var addedScopes bool
+	for _, scope := range additionalScopes {
+		scopes = append(scopes, scope)
+		addedScopes = true
+	}
+
+	now := th.clock.Now()
+	if now.After(th.tokenExpiration) || addedScopes {
+		token, expiration, err := th.fetchToken(params, scopes)
+		if err != nil {
+			return "", err
+		}
+
+		// do not update cache for added scope tokens
+		if !addedScopes {
+			th.tokenCache = token
+			th.tokenExpiration = expiration
+		}
+
+		return token, nil
+	}
+
+	return th.tokenCache, nil
+}
+
+type postTokenResponse struct {
+	AccessToken  string    `json:"access_token"`
+	RefreshToken string    `json:"refresh_token"`
+	ExpiresIn    int       `json:"expires_in"`
+	IssuedAt     time.Time `json:"issued_at"`
+	Scope        string    `json:"scope"`
+}
+
+func (th *tokenHandler) fetchTokenWithOAuth(realm *url.URL, refreshToken, service string, scopes []string) (token string, expiration time.Time, err error) {
+	form := url.Values{}
+	form.Set("scope", strings.Join(scopes, " "))
+	form.Set("service", service)
+
+	clientID := th.clientID
+	if clientID == "" {
+		// Use default client, this is a required field
+		clientID = defaultClientID
+	}
+	form.Set("client_id", clientID)
+
+	if refreshToken != "" {
+		form.Set("grant_type", "refresh_token")
+		form.Set("refresh_token", refreshToken)
+	} else if th.creds != nil {
+		form.Set("grant_type", "password")
+		username, password := th.creds.Basic(realm)
+		form.Set("username", username)
+		form.Set("password", password)
+
+		// attempt to get a refresh token
+		form.Set("access_type", "offline")
+	} else {
+		// refuse to do oauth without a grant type
+		return "", time.Time{}, fmt.Errorf("no supported grant type")
+	}
+
+	resp, err := th.client().PostForm(realm.String(), form)
+	if err != nil {
+		return "", time.Time{}, err
+	}
+	defer resp.Body.Close()
+
+	if !client.SuccessStatus(resp.StatusCode) {
+		err := client.HandleErrorResponse(resp)
+		return "", time.Time{}, err
+	}
+
+	decoder := json.NewDecoder(resp.Body)
+
+	var tr postTokenResponse
+	if err = decoder.Decode(&tr); err != nil {
+		return "", time.Time{}, fmt.Errorf("unable to decode token response: %s", err)
+	}
+
+	if tr.RefreshToken != "" && tr.RefreshToken != refreshToken {
+		th.creds.SetRefreshToken(realm, service, tr.RefreshToken)
+	}
+
+	if tr.ExpiresIn < minimumTokenLifetimeSeconds {
+		// The default/minimum lifetime.
+		tr.ExpiresIn = minimumTokenLifetimeSeconds
+		logrus.Debugf("Increasing token expiration to: %d seconds", tr.ExpiresIn)
+	}
+
+	if tr.IssuedAt.IsZero() {
+		// issued_at is optional in the token response.
+		tr.IssuedAt = th.clock.Now().UTC()
+	}
+
+	return tr.AccessToken, tr.IssuedAt.Add(time.Duration(tr.ExpiresIn) * time.Second), nil
+}
+
+type getTokenResponse struct {
+	Token        string    `json:"token"`
+	AccessToken  string    `json:"access_token"`
+	ExpiresIn    int       `json:"expires_in"`
+	IssuedAt     time.Time `json:"issued_at"`
+	RefreshToken string    `json:"refresh_token"`
+}
+
+func (th *tokenHandler) fetchTokenWithBasicAuth(realm *url.URL, service string, scopes []string) (token string, expiration time.Time, err error) {
+
+	req, err := http.NewRequest("GET", realm.String(), nil)
+	if err != nil {
+		return "", time.Time{}, err
+	}
+
+	reqParams := req.URL.Query()
+
+	if service != "" {
+		reqParams.Add("service", service)
+	}
+
+	for _, scope := range scopes {
+		reqParams.Add("scope", scope)
+	}
+
+	if th.offlineAccess {
+		reqParams.Add("offline_token", "true")
+		clientID := th.clientID
+		if clientID == "" {
+			clientID = defaultClientID
+		}
+		reqParams.Add("client_id", clientID)
+	}
+
+	if th.creds != nil {
+		username, password := th.creds.Basic(realm)
+		if username != "" && password != "" {
+			reqParams.Add("account", username)
+			req.SetBasicAuth(username, password)
+		}
+	}
+
+	req.URL.RawQuery = reqParams.Encode()
+
+	resp, err := th.client().Do(req)
+	if err != nil {
+		return "", time.Time{}, err
+	}
+	defer resp.Body.Close()
+
+	if !client.SuccessStatus(resp.StatusCode) {
+		err := client.HandleErrorResponse(resp)
+		return "", time.Time{}, err
+	}
+
+	decoder := json.NewDecoder(resp.Body)
+
+	var tr getTokenResponse
+	if err = decoder.Decode(&tr); err != nil {
+		return "", time.Time{}, fmt.Errorf("unable to decode token response: %s", err)
+	}
+
+	if tr.RefreshToken != "" && th.creds != nil {
+		th.creds.SetRefreshToken(realm, service, tr.RefreshToken)
+	}
+
+	// `access_token` is equivalent to `token` and if both are specified
+	// the choice is undefined.  Canonicalize `access_token` by sticking
+	// things in `token`.
+	if tr.AccessToken != "" {
+		tr.Token = tr.AccessToken
+	}
+
+	if tr.Token == "" {
+		return "", time.Time{}, ErrNoToken
+	}
+
+	if tr.ExpiresIn < minimumTokenLifetimeSeconds {
+		// The default/minimum lifetime.
+		tr.ExpiresIn = minimumTokenLifetimeSeconds
+		logrus.Debugf("Increasing token expiration to: %d seconds", tr.ExpiresIn)
+	}
+
+	if tr.IssuedAt.IsZero() {
+		// issued_at is optional in the token response.
+		tr.IssuedAt = th.clock.Now().UTC()
+	}
+
+	return tr.Token, tr.IssuedAt.Add(time.Duration(tr.ExpiresIn) * time.Second), nil
+}
+
+func (th *tokenHandler) fetchToken(params map[string]string, scopes []string) (token string, expiration time.Time, err error) {
+	realm, ok := params["realm"]
+	if !ok {
+		return "", time.Time{}, errors.New("no realm specified for token auth challenge")
+	}
+
+	// TODO(dmcgowan): Handle empty scheme and relative realm
+	realmURL, err := url.Parse(realm)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("invalid token auth challenge realm: %s", err)
+	}
+
+	service := params["service"]
+
+	var refreshToken string
+
+	if th.creds != nil {
+		refreshToken = th.creds.RefreshToken(realmURL, service)
+	}
+
+	if refreshToken != "" || th.forceOAuth {
+		return th.fetchTokenWithOAuth(realmURL, refreshToken, service, scopes)
+	}
+
+	return th.fetchTokenWithBasicAuth(realmURL, service, scopes)
+}
+
+type basicHandler struct {
+	creds CredentialStore
+}
+
+// NewBasicHandler creaters a new authentiation handler which adds
+// basic authentication credentials to a request.
+func NewBasicHandler(creds CredentialStore) AuthenticationHandler {
+	return &basicHandler{
+		creds: creds,
+	}
+}
+
+func (*basicHandler) Scheme() string {
+	return "basic"
+}
+
+func (bh *basicHandler) AuthorizeRequest(req *http.Request, params map[string]string) error {
+	if bh.creds != nil {
+		username, password := bh.creds.Basic(req.URL)
+		if username != "" && password != "" {
+			req.SetBasicAuth(username, password)
+			return nil
+		}
+	}
+	return ErrNoBasicAuthCredentials
+}
--- a/vendor/github.com/docker/distribution/registry/client/blob_writer.go
+++ b/vendor/github.com/docker/distribution/registry/client/blob_writer.go
@ -0,0 +1,162 @@
+package client
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/docker/distribution"
+	"github.com/docker/distribution/context"
+)
+
+type httpBlobUpload struct {
+	statter distribution.BlobStatter
+	client  *http.Client
+
+	uuid      string
+	startedAt time.Time
+
+	location string // always the last value of the location header.
+	offset   int64
+	closed   bool
+}
+
+func (hbu *httpBlobUpload) Reader() (io.ReadCloser, error) {
+	panic("Not implemented")
+}
+
+func (hbu *httpBlobUpload) handleErrorResponse(resp *http.Response) error {
+	if resp.StatusCode == http.StatusNotFound {
+		return distribution.ErrBlobUploadUnknown
+	}
+	return HandleErrorResponse(resp)
+}
+
+func (hbu *httpBlobUpload) ReadFrom(r io.Reader) (n int64, err error) {
+	req, err := http.NewRequest("PATCH", hbu.location, ioutil.NopCloser(r))
+	if err != nil {
+		return 0, err
+	}
+	defer req.Body.Close()
+
+	resp, err := hbu.client.Do(req)
+	if err != nil {
+		return 0, err
+	}
+
+	if !SuccessStatus(resp.StatusCode) {
+		return 0, hbu.handleErrorResponse(resp)
+	}
+
+	hbu.uuid = resp.Header.Get("Docker-Upload-UUID")
+	hbu.location, err = sanitizeLocation(resp.Header.Get("Location"), hbu.location)
+	if err != nil {
+		return 0, err
+	}
+	rng := resp.Header.Get("Range")
+	var start, end int64
+	if n, err := fmt.Sscanf(rng, "%d-%d", &start, &end); err != nil {
+		return 0, err
+	} else if n != 2 || end < start {
+		return 0, fmt.Errorf("bad range format: %s", rng)
+	}
+
+	return (end - start + 1), nil
+
+}
+
+func (hbu *httpBlobUpload) Write(p []byte) (n int, err error) {
+	req, err := http.NewRequest("PATCH", hbu.location, bytes.NewReader(p))
+	if err != nil {
+		return 0, err
+	}
+	req.Header.Set("Content-Range", fmt.Sprintf("%d-%d", hbu.offset, hbu.offset+int64(len(p)-1)))
+	req.Header.Set("Content-Length", fmt.Sprintf("%d", len(p)))
+	req.Header.Set("Content-Type", "application/octet-stream")
+
+	resp, err := hbu.client.Do(req)
+	if err != nil {
+		return 0, err
+	}
+
+	if !SuccessStatus(resp.StatusCode) {
+		return 0, hbu.handleErrorResponse(resp)
+	}
+
+	hbu.uuid = resp.Header.Get("Docker-Upload-UUID")
+	hbu.location, err = sanitizeLocation(resp.Header.Get("Location"), hbu.location)
+	if err != nil {
+		return 0, err
+	}
+	rng := resp.Header.Get("Range")
+	var start, end int
+	if n, err := fmt.Sscanf(rng, "%d-%d", &start, &end); err != nil {
+		return 0, err
+	} else if n != 2 || end < start {
+		return 0, fmt.Errorf("bad range format: %s", rng)
+	}
+
+	return (end - start + 1), nil
+
+}
+
+func (hbu *httpBlobUpload) Size() int64 {
+	return hbu.offset
+}
+
+func (hbu *httpBlobUpload) ID() string {
+	return hbu.uuid
+}
+
+func (hbu *httpBlobUpload) StartedAt() time.Time {
+	return hbu.startedAt
+}
+
+func (hbu *httpBlobUpload) Commit(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
+	// TODO(dmcgowan): Check if already finished, if so just fetch
+	req, err := http.NewRequest("PUT", hbu.location, nil)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+
+	values := req.URL.Query()
+	values.Set("digest", desc.Digest.String())
+	req.URL.RawQuery = values.Encode()
+
+	resp, err := hbu.client.Do(req)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	defer resp.Body.Close()
+
+	if !SuccessStatus(resp.StatusCode) {
+		return distribution.Descriptor{}, hbu.handleErrorResponse(resp)
+	}
+
+	return hbu.statter.Stat(ctx, desc.Digest)
+}
+
+func (hbu *httpBlobUpload) Cancel(ctx context.Context) error {
+	req, err := http.NewRequest("DELETE", hbu.location, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := hbu.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotFound || SuccessStatus(resp.StatusCode) {
+		return nil
+	}
+	return hbu.handleErrorResponse(resp)
+}
+
+func (hbu *httpBlobUpload) Close() error {
+	hbu.closed = true
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/client/errors.go
+++ b/vendor/github.com/docker/distribution/registry/client/errors.go
@ -0,0 +1,139 @@
+package client
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/docker/distribution/registry/api/errcode"
+	"github.com/docker/distribution/registry/client/auth/challenge"
+)
+
+// ErrNoErrorsInBody is returned when an HTTP response body parses to an empty
+// errcode.Errors slice.
+var ErrNoErrorsInBody = errors.New("no error details found in HTTP response body")
+
+// UnexpectedHTTPStatusError is returned when an unexpected HTTP status is
+// returned when making a registry api call.
+type UnexpectedHTTPStatusError struct {
+	Status string
+}
+
+func (e *UnexpectedHTTPStatusError) Error() string {
+	return fmt.Sprintf("received unexpected HTTP status: %s", e.Status)
+}
+
+// UnexpectedHTTPResponseError is returned when an expected HTTP status code
+// is returned, but the content was unexpected and failed to be parsed.
+type UnexpectedHTTPResponseError struct {
+	ParseErr   error
+	StatusCode int
+	Response   []byte
+}
+
+func (e *UnexpectedHTTPResponseError) Error() string {
+	return fmt.Sprintf("error parsing HTTP %d response body: %s: %q", e.StatusCode, e.ParseErr.Error(), string(e.Response))
+}
+
+func parseHTTPErrorResponse(statusCode int, r io.Reader) error {
+	var errors errcode.Errors
+	body, err := ioutil.ReadAll(r)
+	if err != nil {
+		return err
+	}
+
+	// For backward compatibility, handle irregularly formatted
+	// messages that contain a "details" field.
+	var detailsErr struct {
+		Details string `json:"details"`
+	}
+	err = json.Unmarshal(body, &detailsErr)
+	if err == nil && detailsErr.Details != "" {
+		switch statusCode {
+		case http.StatusUnauthorized:
+			return errcode.ErrorCodeUnauthorized.WithMessage(detailsErr.Details)
+		case http.StatusTooManyRequests:
+			return errcode.ErrorCodeTooManyRequests.WithMessage(detailsErr.Details)
+		default:
+			return errcode.ErrorCodeUnknown.WithMessage(detailsErr.Details)
+		}
+	}
+
+	if err := json.Unmarshal(body, &errors); err != nil {
+		return &UnexpectedHTTPResponseError{
+			ParseErr:   err,
+			StatusCode: statusCode,
+			Response:   body,
+		}
+	}
+
+	if len(errors) == 0 {
+		// If there was no error specified in the body, return
+		// UnexpectedHTTPResponseError.
+		return &UnexpectedHTTPResponseError{
+			ParseErr:   ErrNoErrorsInBody,
+			StatusCode: statusCode,
+			Response:   body,
+		}
+	}
+
+	return errors
+}
+
+func makeErrorList(err error) []error {
+	if errL, ok := err.(errcode.Errors); ok {
+		return []error(errL)
+	}
+	return []error{err}
+}
+
+func mergeErrors(err1, err2 error) error {
+	return errcode.Errors(append(makeErrorList(err1), makeErrorList(err2)...))
+}
+
+// HandleErrorResponse returns error parsed from HTTP response for an
+// unsuccessful HTTP response code (in the range 400 - 499 inclusive). An
+// UnexpectedHTTPStatusError returned for response code outside of expected
+// range.
+func HandleErrorResponse(resp *http.Response) error {
+	if resp.StatusCode >= 400 && resp.StatusCode < 500 {
+		// Check for OAuth errors within the `WWW-Authenticate` header first
+		// See https://tools.ietf.org/html/rfc6750#section-3
+		for _, c := range challenge.ResponseChallenges(resp) {
+			if c.Scheme == "bearer" {
+				var err errcode.Error
+				// codes defined at https://tools.ietf.org/html/rfc6750#section-3.1
+				switch c.Parameters["error"] {
+				case "invalid_token":
+					err.Code = errcode.ErrorCodeUnauthorized
+				case "insufficient_scope":
+					err.Code = errcode.ErrorCodeDenied
+				default:
+					continue
+				}
+				if description := c.Parameters["error_description"]; description != "" {
+					err.Message = description
+				} else {
+					err.Message = err.Code.Message()
+				}
+
+				return mergeErrors(err, parseHTTPErrorResponse(resp.StatusCode, resp.Body))
+			}
+		}
+		err := parseHTTPErrorResponse(resp.StatusCode, resp.Body)
+		if uErr, ok := err.(*UnexpectedHTTPResponseError); ok && resp.StatusCode == 401 {
+			return errcode.ErrorCodeUnauthorized.WithDetail(uErr.Response)
+		}
+		return err
+	}
+	return &UnexpectedHTTPStatusError{Status: resp.Status}
+}
+
+// SuccessStatus returns true if the argument is a successful HTTP response
+// code (in the range 200 - 399 inclusive).
+func SuccessStatus(status int) bool {
+	return status >= 200 && status <= 399
+}
--- a/vendor/github.com/docker/distribution/registry/client/repository.go
+++ b/vendor/github.com/docker/distribution/registry/client/repository.go
@ -0,0 +1,853 @@
+package client
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/docker/distribution"
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/distribution/registry/api/v2"
+	"github.com/docker/distribution/registry/client/transport"
+	"github.com/docker/distribution/registry/storage/cache"
+	"github.com/docker/distribution/registry/storage/cache/memory"
+	"github.com/opencontainers/go-digest"
+)
+
+// Registry provides an interface for calling Repositories, which returns a catalog of repositories.
+type Registry interface {
+	Repositories(ctx context.Context, repos []string, last string) (n int, err error)
+}
+
+// checkHTTPRedirect is a callback that can manipulate redirected HTTP
+// requests. It is used to preserve Accept and Range headers.
+func checkHTTPRedirect(req *http.Request, via []*http.Request) error {
+	if len(via) >= 10 {
+		return errors.New("stopped after 10 redirects")
+	}
+
+	if len(via) > 0 {
+		for headerName, headerVals := range via[0].Header {
+			if headerName != "Accept" && headerName != "Range" {
+				continue
+			}
+			for _, val := range headerVals {
+				// Don't add to redirected request if redirected
+				// request already has a header with the same
+				// name and value.
+				hasValue := false
+				for _, existingVal := range req.Header[headerName] {
+					if existingVal == val {
+						hasValue = true
+						break
+					}
+				}
+				if !hasValue {
+					req.Header.Add(headerName, val)
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+// NewRegistry creates a registry namespace which can be used to get a listing of repositories
+func NewRegistry(ctx context.Context, baseURL string, transport http.RoundTripper) (Registry, error) {
+	ub, err := v2.NewURLBuilderFromString(baseURL, false)
+	if err != nil {
+		return nil, err
+	}
+
+	client := &http.Client{
+		Transport:     transport,
+		Timeout:       1 * time.Minute,
+		CheckRedirect: checkHTTPRedirect,
+	}
+
+	return &registry{
+		client:  client,
+		ub:      ub,
+		context: ctx,
+	}, nil
+}
+
+type registry struct {
+	client  *http.Client
+	ub      *v2.URLBuilder
+	context context.Context
+}
+
+// Repositories returns a lexigraphically sorted catalog given a base URL.  The 'entries' slice will be filled up to the size
+// of the slice, starting at the value provided in 'last'.  The number of entries will be returned along with io.EOF if there
+// are no more entries
+func (r *registry) Repositories(ctx context.Context, entries []string, last string) (int, error) {
+	var numFilled int
+	var returnErr error
+
+	values := buildCatalogValues(len(entries), last)
+	u, err := r.ub.BuildCatalogURL(values)
+	if err != nil {
+		return 0, err
+	}
+
+	resp, err := r.client.Get(u)
+	if err != nil {
+		return 0, err
+	}
+	defer resp.Body.Close()
+
+	if SuccessStatus(resp.StatusCode) {
+		var ctlg struct {
+			Repositories []string `json:"repositories"`
+		}
+		decoder := json.NewDecoder(resp.Body)
+
+		if err := decoder.Decode(&ctlg); err != nil {
+			return 0, err
+		}
+
+		for cnt := range ctlg.Repositories {
+			entries[cnt] = ctlg.Repositories[cnt]
+		}
+		numFilled = len(ctlg.Repositories)
+
+		link := resp.Header.Get("Link")
+		if link == "" {
+			returnErr = io.EOF
+		}
+	} else {
+		return 0, HandleErrorResponse(resp)
+	}
+
+	return numFilled, returnErr
+}
+
+// NewRepository creates a new Repository for the given repository name and base URL.
+func NewRepository(ctx context.Context, name reference.Named, baseURL string, transport http.RoundTripper) (distribution.Repository, error) {
+	ub, err := v2.NewURLBuilderFromString(baseURL, false)
+	if err != nil {
+		return nil, err
+	}
+
+	client := &http.Client{
+		Transport:     transport,
+		CheckRedirect: checkHTTPRedirect,
+		// TODO(dmcgowan): create cookie jar
+	}
+
+	return &repository{
+		client:  client,
+		ub:      ub,
+		name:    name,
+		context: ctx,
+	}, nil
+}
+
+type repository struct {
+	client  *http.Client
+	ub      *v2.URLBuilder
+	context context.Context
+	name    reference.Named
+}
+
+func (r *repository) Named() reference.Named {
+	return r.name
+}
+
+func (r *repository) Blobs(ctx context.Context) distribution.BlobStore {
+	statter := &blobStatter{
+		name:   r.name,
+		ub:     r.ub,
+		client: r.client,
+	}
+	return &blobs{
+		name:    r.name,
+		ub:      r.ub,
+		client:  r.client,
+		statter: cache.NewCachedBlobStatter(memory.NewInMemoryBlobDescriptorCacheProvider(), statter),
+	}
+}
+
+func (r *repository) Manifests(ctx context.Context, options ...distribution.ManifestServiceOption) (distribution.ManifestService, error) {
+	// todo(richardscothern): options should be sent over the wire
+	return &manifests{
+		name:   r.name,
+		ub:     r.ub,
+		client: r.client,
+		etags:  make(map[string]string),
+	}, nil
+}
+
+func (r *repository) Tags(ctx context.Context) distribution.TagService {
+	return &tags{
+		client:  r.client,
+		ub:      r.ub,
+		context: r.context,
+		name:    r.Named(),
+	}
+}
+
+// tags implements remote tagging operations.
+type tags struct {
+	client  *http.Client
+	ub      *v2.URLBuilder
+	context context.Context
+	name    reference.Named
+}
+
+// All returns all tags
+func (t *tags) All(ctx context.Context) ([]string, error) {
+	var tags []string
+
+	u, err := t.ub.BuildTagsURL(t.name)
+	if err != nil {
+		return tags, err
+	}
+
+	for {
+		resp, err := t.client.Get(u)
+		if err != nil {
+			return tags, err
+		}
+		defer resp.Body.Close()
+
+		if SuccessStatus(resp.StatusCode) {
+			b, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				return tags, err
+			}
+
+			tagsResponse := struct {
+				Tags []string `json:"tags"`
+			}{}
+			if err := json.Unmarshal(b, &tagsResponse); err != nil {
+				return tags, err
+			}
+			tags = append(tags, tagsResponse.Tags...)
+			if link := resp.Header.Get("Link"); link != "" {
+				u = strings.Trim(strings.Split(link, ";")[0], "<>")
+			} else {
+				return tags, nil
+			}
+		} else {
+			return tags, HandleErrorResponse(resp)
+		}
+	}
+}
+
+func descriptorFromResponse(response *http.Response) (distribution.Descriptor, error) {
+	desc := distribution.Descriptor{}
+	headers := response.Header
+
+	ctHeader := headers.Get("Content-Type")
+	if ctHeader == "" {
+		return distribution.Descriptor{}, errors.New("missing or empty Content-Type header")
+	}
+	desc.MediaType = ctHeader
+
+	digestHeader := headers.Get("Docker-Content-Digest")
+	if digestHeader == "" {
+		bytes, err := ioutil.ReadAll(response.Body)
+		if err != nil {
+			return distribution.Descriptor{}, err
+		}
+		_, desc, err := distribution.UnmarshalManifest(ctHeader, bytes)
+		if err != nil {
+			return distribution.Descriptor{}, err
+		}
+		return desc, nil
+	}
+
+	dgst, err := digest.Parse(digestHeader)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	desc.Digest = dgst
+
+	lengthHeader := headers.Get("Content-Length")
+	if lengthHeader == "" {
+		return distribution.Descriptor{}, errors.New("missing or empty Content-Length header")
+	}
+	length, err := strconv.ParseInt(lengthHeader, 10, 64)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	desc.Size = length
+
+	return desc, nil
+
+}
+
+// Get issues a HEAD request for a Manifest against its named endpoint in order
+// to construct a descriptor for the tag.  If the registry doesn't support HEADing
+// a manifest, fallback to GET.
+func (t *tags) Get(ctx context.Context, tag string) (distribution.Descriptor, error) {
+	ref, err := reference.WithTag(t.name, tag)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	u, err := t.ub.BuildManifestURL(ref)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+
+	newRequest := func(method string) (*http.Response, error) {
+		req, err := http.NewRequest(method, u, nil)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, t := range distribution.ManifestMediaTypes() {
+			req.Header.Add("Accept", t)
+		}
+		resp, err := t.client.Do(req)
+		return resp, err
+	}
+
+	resp, err := newRequest("HEAD")
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	defer resp.Body.Close()
+
+	switch {
+	case resp.StatusCode >= 200 && resp.StatusCode < 400:
+		return descriptorFromResponse(resp)
+	default:
+		// if the response is an error - there will be no body to decode.
+		// Issue a GET request:
+		//   - for data from a server that does not handle HEAD
+		//   - to get error details in case of a failure
+		resp, err = newRequest("GET")
+		if err != nil {
+			return distribution.Descriptor{}, err
+		}
+		defer resp.Body.Close()
+
+		if resp.StatusCode >= 200 && resp.StatusCode < 400 {
+			return descriptorFromResponse(resp)
+		}
+		return distribution.Descriptor{}, HandleErrorResponse(resp)
+	}
+}
+
+func (t *tags) Lookup(ctx context.Context, digest distribution.Descriptor) ([]string, error) {
+	panic("not implemented")
+}
+
+func (t *tags) Tag(ctx context.Context, tag string, desc distribution.Descriptor) error {
+	panic("not implemented")
+}
+
+func (t *tags) Untag(ctx context.Context, tag string) error {
+	panic("not implemented")
+}
+
+type manifests struct {
+	name   reference.Named
+	ub     *v2.URLBuilder
+	client *http.Client
+	etags  map[string]string
+}
+
+func (ms *manifests) Exists(ctx context.Context, dgst digest.Digest) (bool, error) {
+	ref, err := reference.WithDigest(ms.name, dgst)
+	if err != nil {
+		return false, err
+	}
+	u, err := ms.ub.BuildManifestURL(ref)
+	if err != nil {
+		return false, err
+	}
+
+	resp, err := ms.client.Head(u)
+	if err != nil {
+		return false, err
+	}
+
+	if SuccessStatus(resp.StatusCode) {
+		return true, nil
+	} else if resp.StatusCode == http.StatusNotFound {
+		return false, nil
+	}
+	return false, HandleErrorResponse(resp)
+}
+
+// AddEtagToTag allows a client to supply an eTag to Get which will be
+// used for a conditional HTTP request.  If the eTag matches, a nil manifest
+// and ErrManifestNotModified error will be returned. etag is automatically
+// quoted when added to this map.
+func AddEtagToTag(tag, etag string) distribution.ManifestServiceOption {
+	return etagOption{tag, etag}
+}
+
+type etagOption struct{ tag, etag string }
+
+func (o etagOption) Apply(ms distribution.ManifestService) error {
+	if ms, ok := ms.(*manifests); ok {
+		ms.etags[o.tag] = fmt.Sprintf(`"%s"`, o.etag)
+		return nil
+	}
+	return fmt.Errorf("etag options is a client-only option")
+}
+
+// ReturnContentDigest allows a client to set a the content digest on
+// a successful request from the 'Docker-Content-Digest' header. This
+// returned digest is represents the digest which the registry uses
+// to refer to the content and can be used to delete the content.
+func ReturnContentDigest(dgst *digest.Digest) distribution.ManifestServiceOption {
+	return contentDigestOption{dgst}
+}
+
+type contentDigestOption struct{ digest *digest.Digest }
+
+func (o contentDigestOption) Apply(ms distribution.ManifestService) error {
+	return nil
+}
+
+func (ms *manifests) Get(ctx context.Context, dgst digest.Digest, options ...distribution.ManifestServiceOption) (distribution.Manifest, error) {
+	var (
+		digestOrTag string
+		ref         reference.Named
+		err         error
+		contentDgst *digest.Digest
+	)
+
+	for _, option := range options {
+		if opt, ok := option.(distribution.WithTagOption); ok {
+			digestOrTag = opt.Tag
+			ref, err = reference.WithTag(ms.name, opt.Tag)
+			if err != nil {
+				return nil, err
+			}
+		} else if opt, ok := option.(contentDigestOption); ok {
+			contentDgst = opt.digest
+		} else {
+			err := option.Apply(ms)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	if digestOrTag == "" {
+		digestOrTag = dgst.String()
+		ref, err = reference.WithDigest(ms.name, dgst)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	u, err := ms.ub.BuildManifestURL(ref)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("GET", u, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, t := range distribution.ManifestMediaTypes() {
+		req.Header.Add("Accept", t)
+	}
+
+	if _, ok := ms.etags[digestOrTag]; ok {
+		req.Header.Set("If-None-Match", ms.etags[digestOrTag])
+	}
+
+	resp, err := ms.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusNotModified {
+		return nil, distribution.ErrManifestNotModified
+	} else if SuccessStatus(resp.StatusCode) {
+		if contentDgst != nil {
+			dgst, err := digest.Parse(resp.Header.Get("Docker-Content-Digest"))
+			if err == nil {
+				*contentDgst = dgst
+			}
+		}
+		mt := resp.Header.Get("Content-Type")
+		body, err := ioutil.ReadAll(resp.Body)
+
+		if err != nil {
+			return nil, err
+		}
+		m, _, err := distribution.UnmarshalManifest(mt, body)
+		if err != nil {
+			return nil, err
+		}
+		return m, nil
+	}
+	return nil, HandleErrorResponse(resp)
+}
+
+// Put puts a manifest.  A tag can be specified using an options parameter which uses some shared state to hold the
+// tag name in order to build the correct upload URL.
+func (ms *manifests) Put(ctx context.Context, m distribution.Manifest, options ...distribution.ManifestServiceOption) (digest.Digest, error) {
+	ref := ms.name
+	var tagged bool
+
+	for _, option := range options {
+		if opt, ok := option.(distribution.WithTagOption); ok {
+			var err error
+			ref, err = reference.WithTag(ref, opt.Tag)
+			if err != nil {
+				return "", err
+			}
+			tagged = true
+		} else {
+			err := option.Apply(ms)
+			if err != nil {
+				return "", err
+			}
+		}
+	}
+	mediaType, p, err := m.Payload()
+	if err != nil {
+		return "", err
+	}
+
+	if !tagged {
+		// generate a canonical digest and Put by digest
+		_, d, err := distribution.UnmarshalManifest(mediaType, p)
+		if err != nil {
+			return "", err
+		}
+		ref, err = reference.WithDigest(ref, d.Digest)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	manifestURL, err := ms.ub.BuildManifestURL(ref)
+	if err != nil {
+		return "", err
+	}
+
+	putRequest, err := http.NewRequest("PUT", manifestURL, bytes.NewReader(p))
+	if err != nil {
+		return "", err
+	}
+
+	putRequest.Header.Set("Content-Type", mediaType)
+
+	resp, err := ms.client.Do(putRequest)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if SuccessStatus(resp.StatusCode) {
+		dgstHeader := resp.Header.Get("Docker-Content-Digest")
+		dgst, err := digest.Parse(dgstHeader)
+		if err != nil {
+			return "", err
+		}
+
+		return dgst, nil
+	}
+
+	return "", HandleErrorResponse(resp)
+}
+
+func (ms *manifests) Delete(ctx context.Context, dgst digest.Digest) error {
+	ref, err := reference.WithDigest(ms.name, dgst)
+	if err != nil {
+		return err
+	}
+	u, err := ms.ub.BuildManifestURL(ref)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequest("DELETE", u, nil)
+	if err != nil {
+		return err
+	}
+
+	resp, err := ms.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if SuccessStatus(resp.StatusCode) {
+		return nil
+	}
+	return HandleErrorResponse(resp)
+}
+
+// todo(richardscothern): Restore interface and implementation with merge of #1050
+/*func (ms *manifests) Enumerate(ctx context.Context, manifests []distribution.Manifest, last distribution.Manifest) (n int, err error) {
+	panic("not supported")
+}*/
+
+type blobs struct {
+	name   reference.Named
+	ub     *v2.URLBuilder
+	client *http.Client
+
+	statter distribution.BlobDescriptorService
+	distribution.BlobDeleter
+}
+
+func sanitizeLocation(location, base string) (string, error) {
+	baseURL, err := url.Parse(base)
+	if err != nil {
+		return "", err
+	}
+
+	locationURL, err := url.Parse(location)
+	if err != nil {
+		return "", err
+	}
+
+	return baseURL.ResolveReference(locationURL).String(), nil
+}
+
+func (bs *blobs) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	return bs.statter.Stat(ctx, dgst)
+
+}
+
+func (bs *blobs) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) {
+	reader, err := bs.Open(ctx, dgst)
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+
+	return ioutil.ReadAll(reader)
+}
+
+func (bs *blobs) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {
+	ref, err := reference.WithDigest(bs.name, dgst)
+	if err != nil {
+		return nil, err
+	}
+	blobURL, err := bs.ub.BuildBlobURL(ref)
+	if err != nil {
+		return nil, err
+	}
+
+	return transport.NewHTTPReadSeeker(bs.client, blobURL,
+		func(resp *http.Response) error {
+			if resp.StatusCode == http.StatusNotFound {
+				return distribution.ErrBlobUnknown
+			}
+			return HandleErrorResponse(resp)
+		}), nil
+}
+
+func (bs *blobs) ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error {
+	panic("not implemented")
+}
+
+func (bs *blobs) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
+	writer, err := bs.Create(ctx)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	dgstr := digest.Canonical.Digester()
+	n, err := io.Copy(writer, io.TeeReader(bytes.NewReader(p), dgstr.Hash()))
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	if n < int64(len(p)) {
+		return distribution.Descriptor{}, fmt.Errorf("short copy: wrote %d of %d", n, len(p))
+	}
+
+	desc := distribution.Descriptor{
+		MediaType: mediaType,
+		Size:      int64(len(p)),
+		Digest:    dgstr.Digest(),
+	}
+
+	return writer.Commit(ctx, desc)
+}
+
+type optionFunc func(interface{}) error
+
+func (f optionFunc) Apply(v interface{}) error {
+	return f(v)
+}
+
+// WithMountFrom returns a BlobCreateOption which designates that the blob should be
+// mounted from the given canonical reference.
+func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
+	return optionFunc(func(v interface{}) error {
+		opts, ok := v.(*distribution.CreateOptions)
+		if !ok {
+			return fmt.Errorf("unexpected options type: %T", v)
+		}
+
+		opts.Mount.ShouldMount = true
+		opts.Mount.From = ref
+
+		return nil
+	})
+}
+
+func (bs *blobs) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
+	var opts distribution.CreateOptions
+
+	for _, option := range options {
+		err := option.Apply(&opts)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var values []url.Values
+
+	if opts.Mount.ShouldMount {
+		values = append(values, url.Values{"from": {opts.Mount.From.Name()}, "mount": {opts.Mount.From.Digest().String()}})
+	}
+
+	u, err := bs.ub.BuildBlobUploadURL(bs.name, values...)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := bs.client.Post(u, "", nil)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	switch resp.StatusCode {
+	case http.StatusCreated:
+		desc, err := bs.statter.Stat(ctx, opts.Mount.From.Digest())
+		if err != nil {
+			return nil, err
+		}
+		return nil, distribution.ErrBlobMounted{From: opts.Mount.From, Descriptor: desc}
+	case http.StatusAccepted:
+		// TODO(dmcgowan): Check for invalid UUID
+		uuid := resp.Header.Get("Docker-Upload-UUID")
+		location, err := sanitizeLocation(resp.Header.Get("Location"), u)
+		if err != nil {
+			return nil, err
+		}
+
+		return &httpBlobUpload{
+			statter:   bs.statter,
+			client:    bs.client,
+			uuid:      uuid,
+			startedAt: time.Now(),
+			location:  location,
+		}, nil
+	default:
+		return nil, HandleErrorResponse(resp)
+	}
+}
+
+func (bs *blobs) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
+	panic("not implemented")
+}
+
+func (bs *blobs) Delete(ctx context.Context, dgst digest.Digest) error {
+	return bs.statter.Clear(ctx, dgst)
+}
+
+type blobStatter struct {
+	name   reference.Named
+	ub     *v2.URLBuilder
+	client *http.Client
+}
+
+func (bs *blobStatter) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	ref, err := reference.WithDigest(bs.name, dgst)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	u, err := bs.ub.BuildBlobURL(ref)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+
+	resp, err := bs.client.Head(u)
+	if err != nil {
+		return distribution.Descriptor{}, err
+	}
+	defer resp.Body.Close()
+
+	if SuccessStatus(resp.StatusCode) {
+		lengthHeader := resp.Header.Get("Content-Length")
+		if lengthHeader == "" {
+			return distribution.Descriptor{}, fmt.Errorf("missing content-length header for request: %s", u)
+		}
+
+		length, err := strconv.ParseInt(lengthHeader, 10, 64)
+		if err != nil {
+			return distribution.Descriptor{}, fmt.Errorf("error parsing content-length: %v", err)
+		}
+
+		return distribution.Descriptor{
+			MediaType: resp.Header.Get("Content-Type"),
+			Size:      length,
+			Digest:    dgst,
+		}, nil
+	} else if resp.StatusCode == http.StatusNotFound {
+		return distribution.Descriptor{}, distribution.ErrBlobUnknown
+	}
+	return distribution.Descriptor{}, HandleErrorResponse(resp)
+}
+
+func buildCatalogValues(maxEntries int, last string) url.Values {
+	values := url.Values{}
+
+	if maxEntries > 0 {
+		values.Add("n", strconv.Itoa(maxEntries))
+	}
+
+	if last != "" {
+		values.Add("last", last)
+	}
+
+	return values
+}
+
+func (bs *blobStatter) Clear(ctx context.Context, dgst digest.Digest) error {
+	ref, err := reference.WithDigest(bs.name, dgst)
+	if err != nil {
+		return err
+	}
+	blobURL, err := bs.ub.BuildBlobURL(ref)
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequest("DELETE", blobURL, nil)
+	if err != nil {
+		return err
+	}
+
+	resp, err := bs.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if SuccessStatus(resp.StatusCode) {
+		return nil
+	}
+	return HandleErrorResponse(resp)
+}
+
+func (bs *blobStatter) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/client/transport/http_reader.go
+++ b/vendor/github.com/docker/distribution/registry/client/transport/http_reader.go
@ -0,0 +1,251 @@
+package transport
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+var (
+	contentRangeRegexp = regexp.MustCompile(`bytes ([0-9]+)-([0-9]+)/([0-9]+|\\*)`)
+
+	// ErrWrongCodeForByteRange is returned if the client sends a request
+	// with a Range header but the server returns a 2xx or 3xx code other
+	// than 206 Partial Content.
+	ErrWrongCodeForByteRange = errors.New("expected HTTP 206 from byte range request")
+)
+
+// ReadSeekCloser combines io.ReadSeeker with io.Closer.
+type ReadSeekCloser interface {
+	io.ReadSeeker
+	io.Closer
+}
+
+// NewHTTPReadSeeker handles reading from an HTTP endpoint using a GET
+// request. When seeking and starting a read from a non-zero offset
+// the a "Range" header will be added which sets the offset.
+// TODO(dmcgowan): Move this into a separate utility package
+func NewHTTPReadSeeker(client *http.Client, url string, errorHandler func(*http.Response) error) ReadSeekCloser {
+	return &httpReadSeeker{
+		client:       client,
+		url:          url,
+		errorHandler: errorHandler,
+	}
+}
+
+type httpReadSeeker struct {
+	client *http.Client
+	url    string
+
+	// errorHandler creates an error from an unsuccessful HTTP response.
+	// This allows the error to be created with the HTTP response body
+	// without leaking the body through a returned error.
+	errorHandler func(*http.Response) error
+
+	size int64
+
+	// rc is the remote read closer.
+	rc io.ReadCloser
+	// readerOffset tracks the offset as of the last read.
+	readerOffset int64
+	// seekOffset allows Seek to override the offset. Seek changes
+	// seekOffset instead of changing readOffset directly so that
+	// connection resets can be delayed and possibly avoided if the
+	// seek is undone (i.e. seeking to the end and then back to the
+	// beginning).
+	seekOffset int64
+	err        error
+}
+
+func (hrs *httpReadSeeker) Read(p []byte) (n int, err error) {
+	if hrs.err != nil {
+		return 0, hrs.err
+	}
+
+	// If we sought to a different position, we need to reset the
+	// connection. This logic is here instead of Seek so that if
+	// a seek is undone before the next read, the connection doesn't
+	// need to be closed and reopened. A common example of this is
+	// seeking to the end to determine the length, and then seeking
+	// back to the original position.
+	if hrs.readerOffset != hrs.seekOffset {
+		hrs.reset()
+	}
+
+	hrs.readerOffset = hrs.seekOffset
+
+	rd, err := hrs.reader()
+	if err != nil {
+		return 0, err
+	}
+
+	n, err = rd.Read(p)
+	hrs.seekOffset += int64(n)
+	hrs.readerOffset += int64(n)
+
+	return n, err
+}
+
+func (hrs *httpReadSeeker) Seek(offset int64, whence int) (int64, error) {
+	if hrs.err != nil {
+		return 0, hrs.err
+	}
+
+	lastReaderOffset := hrs.readerOffset
+
+	if whence == os.SEEK_SET && hrs.rc == nil {
+		// If no request has been made yet, and we are seeking to an
+		// absolute position, set the read offset as well to avoid an
+		// unnecessary request.
+		hrs.readerOffset = offset
+	}
+
+	_, err := hrs.reader()
+	if err != nil {
+		hrs.readerOffset = lastReaderOffset
+		return 0, err
+	}
+
+	newOffset := hrs.seekOffset
+
+	switch whence {
+	case os.SEEK_CUR:
+		newOffset += offset
+	case os.SEEK_END:
+		if hrs.size < 0 {
+			return 0, errors.New("content length not known")
+		}
+		newOffset = hrs.size + offset
+	case os.SEEK_SET:
+		newOffset = offset
+	}
+
+	if newOffset < 0 {
+		err = errors.New("cannot seek to negative position")
+	} else {
+		hrs.seekOffset = newOffset
+	}
+
+	return hrs.seekOffset, err
+}
+
+func (hrs *httpReadSeeker) Close() error {
+	if hrs.err != nil {
+		return hrs.err
+	}
+
+	// close and release reader chain
+	if hrs.rc != nil {
+		hrs.rc.Close()
+	}
+
+	hrs.rc = nil
+
+	hrs.err = errors.New("httpLayer: closed")
+
+	return nil
+}
+
+func (hrs *httpReadSeeker) reset() {
+	if hrs.err != nil {
+		return
+	}
+	if hrs.rc != nil {
+		hrs.rc.Close()
+		hrs.rc = nil
+	}
+}
+
+func (hrs *httpReadSeeker) reader() (io.Reader, error) {
+	if hrs.err != nil {
+		return nil, hrs.err
+	}
+
+	if hrs.rc != nil {
+		return hrs.rc, nil
+	}
+
+	req, err := http.NewRequest("GET", hrs.url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if hrs.readerOffset > 0 {
+		// If we are at different offset, issue a range request from there.
+		req.Header.Add("Range", fmt.Sprintf("bytes=%d-", hrs.readerOffset))
+		// TODO: get context in here
+		// context.GetLogger(hrs.context).Infof("Range: %s", req.Header.Get("Range"))
+	}
+
+	req.Header.Add("Accept-Encoding", "identity")
+	resp, err := hrs.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	// Normally would use client.SuccessStatus, but that would be a cyclic
+	// import
+	if resp.StatusCode >= 200 && resp.StatusCode <= 399 {
+		if hrs.readerOffset > 0 {
+			if resp.StatusCode != http.StatusPartialContent {
+				return nil, ErrWrongCodeForByteRange
+			}
+
+			contentRange := resp.Header.Get("Content-Range")
+			if contentRange == "" {
+				return nil, errors.New("no Content-Range header found in HTTP 206 response")
+			}
+
+			submatches := contentRangeRegexp.FindStringSubmatch(contentRange)
+			if len(submatches) < 4 {
+				return nil, fmt.Errorf("could not parse Content-Range header: %s", contentRange)
+			}
+
+			startByte, err := strconv.ParseUint(submatches[1], 10, 64)
+			if err != nil {
+				return nil, fmt.Errorf("could not parse start of range in Content-Range header: %s", contentRange)
+			}
+
+			if startByte != uint64(hrs.readerOffset) {
+				return nil, fmt.Errorf("received Content-Range starting at offset %d instead of requested %d", startByte, hrs.readerOffset)
+			}
+
+			endByte, err := strconv.ParseUint(submatches[2], 10, 64)
+			if err != nil {
+				return nil, fmt.Errorf("could not parse end of range in Content-Range header: %s", contentRange)
+			}
+
+			if submatches[3] == "*" {
+				hrs.size = -1
+			} else {
+				size, err := strconv.ParseUint(submatches[3], 10, 64)
+				if err != nil {
+					return nil, fmt.Errorf("could not parse total size in Content-Range header: %s", contentRange)
+				}
+
+				if endByte+1 != size {
+					return nil, fmt.Errorf("range in Content-Range stops before the end of the content: %s", contentRange)
+				}
+
+				hrs.size = int64(size)
+			}
+		} else if resp.StatusCode == http.StatusOK {
+			hrs.size = resp.ContentLength
+		} else {
+			hrs.size = -1
+		}
+		hrs.rc = resp.Body
+	} else {
+		defer resp.Body.Close()
+		if hrs.errorHandler != nil {
+			return nil, hrs.errorHandler(resp)
+		}
+		return nil, fmt.Errorf("unexpected status resolving reader: %v", resp.Status)
+	}
+
+	return hrs.rc, nil
+}
--- a/vendor/github.com/docker/distribution/registry/client/transport/transport.go
+++ b/vendor/github.com/docker/distribution/registry/client/transport/transport.go
@ -0,0 +1,147 @@
+package transport
+
+import (
+	"io"
+	"net/http"
+	"sync"
+)
+
+// RequestModifier represents an object which will do an inplace
+// modification of an HTTP request.
+type RequestModifier interface {
+	ModifyRequest(*http.Request) error
+}
+
+type headerModifier http.Header
+
+// NewHeaderRequestModifier returns a new RequestModifier which will
+// add the given headers to a request.
+func NewHeaderRequestModifier(header http.Header) RequestModifier {
+	return headerModifier(header)
+}
+
+func (h headerModifier) ModifyRequest(req *http.Request) error {
+	for k, s := range http.Header(h) {
+		req.Header[k] = append(req.Header[k], s...)
+	}
+
+	return nil
+}
+
+// NewTransport creates a new transport which will apply modifiers to
+// the request on a RoundTrip call.
+func NewTransport(base http.RoundTripper, modifiers ...RequestModifier) http.RoundTripper {
+	return &transport{
+		Modifiers: modifiers,
+		Base:      base,
+	}
+}
+
+// transport is an http.RoundTripper that makes HTTP requests after
+// copying and modifying the request
+type transport struct {
+	Modifiers []RequestModifier
+	Base      http.RoundTripper
+
+	mu     sync.Mutex                      // guards modReq
+	modReq map[*http.Request]*http.Request // original -> modified
+}
+
+// RoundTrip authorizes and authenticates the request with an
+// access token. If no token exists or token is expired,
+// tries to refresh/fetch a new token.
+func (t *transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	req2 := cloneRequest(req)
+	for _, modifier := range t.Modifiers {
+		if err := modifier.ModifyRequest(req2); err != nil {
+			return nil, err
+		}
+	}
+
+	t.setModReq(req, req2)
+	res, err := t.base().RoundTrip(req2)
+	if err != nil {
+		t.setModReq(req, nil)
+		return nil, err
+	}
+	res.Body = &onEOFReader{
+		rc: res.Body,
+		fn: func() { t.setModReq(req, nil) },
+	}
+	return res, nil
+}
+
+// CancelRequest cancels an in-flight request by closing its connection.
+func (t *transport) CancelRequest(req *http.Request) {
+	type canceler interface {
+		CancelRequest(*http.Request)
+	}
+	if cr, ok := t.base().(canceler); ok {
+		t.mu.Lock()
+		modReq := t.modReq[req]
+		delete(t.modReq, req)
+		t.mu.Unlock()
+		cr.CancelRequest(modReq)
+	}
+}
+
+func (t *transport) base() http.RoundTripper {
+	if t.Base != nil {
+		return t.Base
+	}
+	return http.DefaultTransport
+}
+
+func (t *transport) setModReq(orig, mod *http.Request) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.modReq == nil {
+		t.modReq = make(map[*http.Request]*http.Request)
+	}
+	if mod == nil {
+		delete(t.modReq, orig)
+	} else {
+		t.modReq[orig] = mod
+	}
+}
+
+// cloneRequest returns a clone of the provided *http.Request.
+// The clone is a shallow copy of the struct and its Header map.
+func cloneRequest(r *http.Request) *http.Request {
+	// shallow copy of the struct
+	r2 := new(http.Request)
+	*r2 = *r
+	// deep copy of the Header
+	r2.Header = make(http.Header, len(r.Header))
+	for k, s := range r.Header {
+		r2.Header[k] = append([]string(nil), s...)
+	}
+
+	return r2
+}
+
+type onEOFReader struct {
+	rc io.ReadCloser
+	fn func()
+}
+
+func (r *onEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+func (r *onEOFReader) Close() error {
+	err := r.rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *onEOFReader) runFunc() {
+	if fn := r.fn; fn != nil {
+		fn()
+		r.fn = nil
+	}
+}
--- a/vendor/github.com/docker/distribution/registry/storage/cache/cache.go
+++ b/vendor/github.com/docker/distribution/registry/storage/cache/cache.go
@ -0,0 +1,35 @@
+// Package cache provides facilities to speed up access to the storage
+// backend.
+package cache
+
+import (
+	"fmt"
+
+	"github.com/docker/distribution"
+)
+
+// BlobDescriptorCacheProvider provides repository scoped
+// BlobDescriptorService cache instances and a global descriptor cache.
+type BlobDescriptorCacheProvider interface {
+	distribution.BlobDescriptorService
+
+	RepositoryScoped(repo string) (distribution.BlobDescriptorService, error)
+}
+
+// ValidateDescriptor provides a helper function to ensure that caches have
+// common criteria for admitting descriptors.
+func ValidateDescriptor(desc distribution.Descriptor) error {
+	if err := desc.Digest.Validate(); err != nil {
+		return err
+	}
+
+	if desc.Size < 0 {
+		return fmt.Errorf("cache: invalid length in descriptor: %v < 0", desc.Size)
+	}
+
+	if desc.MediaType == "" {
+		return fmt.Errorf("cache: empty mediatype on descriptor: %v", desc)
+	}
+
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/storage/cache/cachedblobdescriptorstore.go
+++ b/vendor/github.com/docker/distribution/registry/storage/cache/cachedblobdescriptorstore.go
@ -0,0 +1,101 @@
+package cache
+
+import (
+	"github.com/docker/distribution/context"
+	"github.com/opencontainers/go-digest"
+
+	"github.com/docker/distribution"
+)
+
+// Metrics is used to hold metric counters
+// related to the number of times a cache was
+// hit or missed.
+type Metrics struct {
+	Requests uint64
+	Hits     uint64
+	Misses   uint64
+}
+
+// MetricsTracker represents a metric tracker
+// which simply counts the number of hits and misses.
+type MetricsTracker interface {
+	Hit()
+	Miss()
+	Metrics() Metrics
+}
+
+type cachedBlobStatter struct {
+	cache   distribution.BlobDescriptorService
+	backend distribution.BlobDescriptorService
+	tracker MetricsTracker
+}
+
+// NewCachedBlobStatter creates a new statter which prefers a cache and
+// falls back to a backend.
+func NewCachedBlobStatter(cache distribution.BlobDescriptorService, backend distribution.BlobDescriptorService) distribution.BlobDescriptorService {
+	return &cachedBlobStatter{
+		cache:   cache,
+		backend: backend,
+	}
+}
+
+// NewCachedBlobStatterWithMetrics creates a new statter which prefers a cache and
+// falls back to a backend. Hits and misses will send to the tracker.
+func NewCachedBlobStatterWithMetrics(cache distribution.BlobDescriptorService, backend distribution.BlobDescriptorService, tracker MetricsTracker) distribution.BlobStatter {
+	return &cachedBlobStatter{
+		cache:   cache,
+		backend: backend,
+		tracker: tracker,
+	}
+}
+
+func (cbds *cachedBlobStatter) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	desc, err := cbds.cache.Stat(ctx, dgst)
+	if err != nil {
+		if err != distribution.ErrBlobUnknown {
+			context.GetLogger(ctx).Errorf("error retrieving descriptor from cache: %v", err)
+		}
+
+		goto fallback
+	}
+
+	if cbds.tracker != nil {
+		cbds.tracker.Hit()
+	}
+	return desc, nil
+fallback:
+	if cbds.tracker != nil {
+		cbds.tracker.Miss()
+	}
+	desc, err = cbds.backend.Stat(ctx, dgst)
+	if err != nil {
+		return desc, err
+	}
+
+	if err := cbds.cache.SetDescriptor(ctx, dgst, desc); err != nil {
+		context.GetLogger(ctx).Errorf("error adding descriptor %v to cache: %v", desc.Digest, err)
+	}
+
+	return desc, err
+
+}
+
+func (cbds *cachedBlobStatter) Clear(ctx context.Context, dgst digest.Digest) error {
+	err := cbds.cache.Clear(ctx, dgst)
+	if err != nil {
+		return err
+	}
+
+	err = cbds.backend.Clear(ctx, dgst)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (cbds *cachedBlobStatter) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
+	if err := cbds.cache.SetDescriptor(ctx, dgst, desc); err != nil {
+		context.GetLogger(ctx).Errorf("error adding descriptor %v to cache: %v", desc.Digest, err)
+	}
+	return nil
+}
--- a/vendor/github.com/docker/distribution/registry/storage/cache/memory/memory.go
+++ b/vendor/github.com/docker/distribution/registry/storage/cache/memory/memory.go
@ -0,0 +1,179 @@
+package memory
+
+import (
+	"sync"
+
+	"github.com/docker/distribution"
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/distribution/registry/storage/cache"
+	"github.com/opencontainers/go-digest"
+)
+
+type inMemoryBlobDescriptorCacheProvider struct {
+	global       *mapBlobDescriptorCache
+	repositories map[string]*mapBlobDescriptorCache
+	mu           sync.RWMutex
+}
+
+// NewInMemoryBlobDescriptorCacheProvider returns a new mapped-based cache for
+// storing blob descriptor data.
+func NewInMemoryBlobDescriptorCacheProvider() cache.BlobDescriptorCacheProvider {
+	return &inMemoryBlobDescriptorCacheProvider{
+		global:       newMapBlobDescriptorCache(),
+		repositories: make(map[string]*mapBlobDescriptorCache),
+	}
+}
+
+func (imbdcp *inMemoryBlobDescriptorCacheProvider) RepositoryScoped(repo string) (distribution.BlobDescriptorService, error) {
+	if _, err := reference.ParseNormalizedNamed(repo); err != nil {
+		return nil, err
+	}
+
+	imbdcp.mu.RLock()
+	defer imbdcp.mu.RUnlock()
+
+	return &repositoryScopedInMemoryBlobDescriptorCache{
+		repo:       repo,
+		parent:     imbdcp,
+		repository: imbdcp.repositories[repo],
+	}, nil
+}
+
+func (imbdcp *inMemoryBlobDescriptorCacheProvider) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	return imbdcp.global.Stat(ctx, dgst)
+}
+
+func (imbdcp *inMemoryBlobDescriptorCacheProvider) Clear(ctx context.Context, dgst digest.Digest) error {
+	return imbdcp.global.Clear(ctx, dgst)
+}
+
+func (imbdcp *inMemoryBlobDescriptorCacheProvider) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
+	_, err := imbdcp.Stat(ctx, dgst)
+	if err == distribution.ErrBlobUnknown {
+
+		if dgst.Algorithm() != desc.Digest.Algorithm() && dgst != desc.Digest {
+			// if the digests differ, set the other canonical mapping
+			if err := imbdcp.global.SetDescriptor(ctx, desc.Digest, desc); err != nil {
+				return err
+			}
+		}
+
+		// unknown, just set it
+		return imbdcp.global.SetDescriptor(ctx, dgst, desc)
+	}
+
+	// we already know it, do nothing
+	return err
+}
+
+// repositoryScopedInMemoryBlobDescriptorCache provides the request scoped
+// repository cache. Instances are not thread-safe but the delegated
+// operations are.
+type repositoryScopedInMemoryBlobDescriptorCache struct {
+	repo       string
+	parent     *inMemoryBlobDescriptorCacheProvider // allows lazy allocation of repo's map
+	repository *mapBlobDescriptorCache
+}
+
+func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	rsimbdcp.parent.mu.Lock()
+	repo := rsimbdcp.repository
+	rsimbdcp.parent.mu.Unlock()
+
+	if repo == nil {
+		return distribution.Descriptor{}, distribution.ErrBlobUnknown
+	}
+
+	return repo.Stat(ctx, dgst)
+}
+
+func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) Clear(ctx context.Context, dgst digest.Digest) error {
+	rsimbdcp.parent.mu.Lock()
+	repo := rsimbdcp.repository
+	rsimbdcp.parent.mu.Unlock()
+
+	if repo == nil {
+		return distribution.ErrBlobUnknown
+	}
+
+	return repo.Clear(ctx, dgst)
+}
+
+func (rsimbdcp *repositoryScopedInMemoryBlobDescriptorCache) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
+	rsimbdcp.parent.mu.Lock()
+	repo := rsimbdcp.repository
+	if repo == nil {
+		// allocate map since we are setting it now.
+		var ok bool
+		// have to read back value since we may have allocated elsewhere.
+		repo, ok = rsimbdcp.parent.repositories[rsimbdcp.repo]
+		if !ok {
+			repo = newMapBlobDescriptorCache()
+			rsimbdcp.parent.repositories[rsimbdcp.repo] = repo
+		}
+		rsimbdcp.repository = repo
+	}
+	rsimbdcp.parent.mu.Unlock()
+
+	if err := repo.SetDescriptor(ctx, dgst, desc); err != nil {
+		return err
+	}
+
+	return rsimbdcp.parent.SetDescriptor(ctx, dgst, desc)
+}
+
+// mapBlobDescriptorCache provides a simple map-based implementation of the
+// descriptor cache.
+type mapBlobDescriptorCache struct {
+	descriptors map[digest.Digest]distribution.Descriptor
+	mu          sync.RWMutex
+}
+
+var _ distribution.BlobDescriptorService = &mapBlobDescriptorCache{}
+
+func newMapBlobDescriptorCache() *mapBlobDescriptorCache {
+	return &mapBlobDescriptorCache{
+		descriptors: make(map[digest.Digest]distribution.Descriptor),
+	}
+}
+
+func (mbdc *mapBlobDescriptorCache) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
+	if err := dgst.Validate(); err != nil {
+		return distribution.Descriptor{}, err
+	}
+
+	mbdc.mu.RLock()
+	defer mbdc.mu.RUnlock()
+
+	desc, ok := mbdc.descriptors[dgst]
+	if !ok {
+		return distribution.Descriptor{}, distribution.ErrBlobUnknown
+	}
+
+	return desc, nil
+}
+
+func (mbdc *mapBlobDescriptorCache) Clear(ctx context.Context, dgst digest.Digest) error {
+	mbdc.mu.Lock()
+	defer mbdc.mu.Unlock()
+
+	delete(mbdc.descriptors, dgst)
+	return nil
+}
+
+func (mbdc *mapBlobDescriptorCache) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
+	if err := dgst.Validate(); err != nil {
+		return err
+	}
+
+	if err := cache.ValidateDescriptor(desc); err != nil {
+		return err
+	}
+
+	mbdc.mu.Lock()
+	defer mbdc.mu.Unlock()
+
+	mbdc.descriptors[dgst] = desc
+	return nil
+}