docker api

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
+}

vendor/github.com/docker/distribution/registry/api/errcode/handler.go

@@ -0,0 +1,40 @@
+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)
+
+	return json.NewEncoder(w).Encode(err)
+}

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
+}