distribution/registry/api/errcode/register.go
Stephen J Day f141480d98 Move common error codes to errcode package
Several error codes are generally useful but tied to the v2 specification
definitions. This change moves these error code definitions into the common
package for use by the health package, which is not tied to the v2 API.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-08-11 11:50:58 -07:00

116 lines
3.6 KiB
Go

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.StatusBadRequest,
})
// ErrorCodeUnauthorized is returned if a request is not authorized.
ErrorCodeUnauthorized = Register("errcode", ErrorDescriptor{
Value: "UNAUTHORIZED",
Message: "access to the requested resource is not authorized",
Description: `The access controller denied access for the operation on
a resource. Often this will be accompanied by a 401 Unauthorized
response status.`,
HTTPStatusCode: http.StatusUnauthorized,
})
// ErrorCodeUnavailable provides a common error to report unavialability
// 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,
})
)
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
}