Move registry api definitions under registry package

Signed-off-by: Stephen J Day <stephen.day@docker.com>

registry/api/v2/errors.go

@@ -0,0 +1,191 @@
+package v2
+
+import (
+	"fmt"
+	"strings"
+)
+
+// 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
+
+const (
+	// ErrorCodeUnknown is a catch-all for errors not defined below.
+	ErrorCodeUnknown ErrorCode = iota
+
+	// ErrorCodeUnauthorized is returned if a request is not authorized.
+	ErrorCodeUnauthorized
+
+	// ErrorCodeDigestInvalid is returned when uploading a blob if the
+	// provided digest does not match the blob contents.
+	ErrorCodeDigestInvalid
+
+	// ErrorCodeSizeInvalid is returned when uploading a blob if the provided
+	// size does not match the content length.
+	ErrorCodeSizeInvalid
+
+	// ErrorCodeNameInvalid is returned when the name in the manifest does not
+	// match the provided name.
+	ErrorCodeNameInvalid
+
+	// ErrorCodeTagInvalid is returned when the tag in the manifest does not
+	// match the provided tag.
+	ErrorCodeTagInvalid
+
+	// ErrorCodeNameUnknown when the repository name is not known.
+	ErrorCodeNameUnknown
+
+	// ErrorCodeManifestUnknown returned when image manifest is unknown.
+	ErrorCodeManifestUnknown
+
+	// 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
+
+	// ErrorCodeManifestUnverified is returned when the manifest fails
+	// signature verfication.
+	ErrorCodeManifestUnverified
+
+	// 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
+
+	// ErrorCodeBlobUploadUnknown is returned when an upload is unknown.
+	ErrorCodeBlobUploadUnknown
+
+	// ErrorCodeBlobUploadInvalid is returned when an upload is invalid.
+	ErrorCodeBlobUploadInvalid
+)
+
+// ParseErrorCode attempts to parse the error code string, returning
+// ErrorCodeUnknown if the error is not known.
+func ParseErrorCode(s string) ErrorCode {
+	desc, ok := idToDescriptors[s]
+
+	if !ok {
+		return ErrorCodeUnknown
+	}
+
+	return desc.Code
+}
+
+// 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
+}
+
+// Error provides a wrapper around ErrorCode with extra Details provided.
+type Error struct {
+	Code    ErrorCode   `json:"code"`
+	Message string      `json:"message,omitempty"`
+	Detail  interface{} `json:"detail,omitempty"`
+}
+
+// Error returns a human readable representation of the error.
+func (e Error) Error() string {
+	return fmt.Sprintf("%s: %s",
+		strings.ToLower(strings.Replace(e.Code.String(), "_", " ", -1)),
+		e.Message)
+}
+
+// Errors provides the envelope for multiple errors and a few sugar methods
+// for use within the application.
+type Errors struct {
+	Errors []Error `json:"errors,omitempty"`
+}
+
+// Push pushes an error on to the error stack, with the optional detail
+// argument. It is a programming error (ie panic) to push more than one
+// detail at a time.
+func (errs *Errors) Push(code ErrorCode, details ...interface{}) {
+	if len(details) > 1 {
+		panic("please specify zero or one detail items for this error")
+	}
+
+	var detail interface{}
+	if len(details) > 0 {
+		detail = details[0]
+	}
+
+	if err, ok := detail.(error); ok {
+		detail = err.Error()
+	}
+
+	errs.PushErr(Error{
+		Code:    code,
+		Message: code.Message(),
+		Detail:  detail,
+	})
+}
+
+// PushErr pushes an error interface onto the error stack.
+func (errs *Errors) PushErr(err error) {
+	switch err.(type) {
+	case Error:
+		errs.Errors = append(errs.Errors, err.(Error))
+	default:
+		errs.Errors = append(errs.Errors, Error{Message: err.Error()})
+	}
+}
+
+func (errs *Errors) Error() string {
+	switch errs.Len() {
+	case 0:
+		return "<nil>"
+	case 1:
+		return errs.Errors[0].Error()
+	default:
+		msg := "errors:\n"
+		for _, err := range errs.Errors {
+			msg += err.Error() + "\n"
+		}
+		return msg
+	}
+}
+
+// Clear clears the errors.
+func (errs *Errors) Clear() {
+	errs.Errors = errs.Errors[:0]
+}
+
+// Len returns the current number of errors.
+func (errs *Errors) Len() int {
+	return len(errs.Errors)
+}