distribution/docs/api/errcode/register.go
Josh Hawn fa4c33f5f3 [api spec] Update authN and authZ errors
Associate HTTP 401s with Authentication errors rather than Authorization
errors. Changes the meaning of the UNAUTHORIZED error to be authentication
specific.

Defines DENIED error code to be associated with authorization
errors which result in HTTP 403 responses.

Add 'No Such Repository' errors to more endpoints.

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
2015-09-30 09:12:31 -07:00

128 lines
3.9 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.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 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
}