prometheus/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
Ganesh Vernekar c729df3d0f
Update dependencies (#7331)
* Update dependencies

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

* Update protos

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
2020-06-04 11:25:56 +05:30

170 lines
6 KiB
Go

package runtime
import (
"context"
"io"
"net/http"
"github.com/grpc-ecosystem/grpc-gateway/internal"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/status"
)
// HTTPStatusFromCode converts a gRPC error code into the corresponding HTTP response status.
// See: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
func HTTPStatusFromCode(code codes.Code) int {
switch code {
case codes.OK:
return http.StatusOK
case codes.Canceled:
return http.StatusRequestTimeout
case codes.Unknown:
return http.StatusInternalServerError
case codes.InvalidArgument:
return http.StatusBadRequest
case codes.DeadlineExceeded:
return http.StatusGatewayTimeout
case codes.NotFound:
return http.StatusNotFound
case codes.AlreadyExists:
return http.StatusConflict
case codes.PermissionDenied:
return http.StatusForbidden
case codes.Unauthenticated:
return http.StatusUnauthorized
case codes.ResourceExhausted:
return http.StatusTooManyRequests
case codes.FailedPrecondition:
// Note, this deliberately doesn't translate to the similarly named '412 Precondition Failed' HTTP response status.
return http.StatusBadRequest
case codes.Aborted:
return http.StatusConflict
case codes.OutOfRange:
return http.StatusBadRequest
case codes.Unimplemented:
return http.StatusNotImplemented
case codes.Internal:
return http.StatusInternalServerError
case codes.Unavailable:
return http.StatusServiceUnavailable
case codes.DataLoss:
return http.StatusInternalServerError
}
grpclog.Infof("Unknown gRPC error code: %v", code)
return http.StatusInternalServerError
}
var (
// HTTPError replies to the request with an error.
//
// HTTPError is called:
// - From generated per-endpoint gateway handler code, when calling the backend results in an error.
// - From gateway runtime code, when forwarding the response message results in an error.
//
// The default value for HTTPError calls the custom error handler configured on the ServeMux via the
// WithProtoErrorHandler serve option if that option was used, calling GlobalHTTPErrorHandler otherwise.
//
// To customize the error handling of a particular ServeMux instance, use the WithProtoErrorHandler
// serve option.
//
// To customize the error format for all ServeMux instances not using the WithProtoErrorHandler serve
// option, set GlobalHTTPErrorHandler to a custom function.
//
// Setting this variable directly to customize error format is deprecated.
HTTPError = MuxOrGlobalHTTPError
// GlobalHTTPErrorHandler is the HTTPError handler for all ServeMux instances not using the
// WithProtoErrorHandler serve option.
//
// You can set a custom function to this variable to customize error format.
GlobalHTTPErrorHandler = DefaultHTTPError
// OtherErrorHandler handles gateway errors from parsing and routing client requests for all
// ServeMux instances not using the WithProtoErrorHandler serve option.
//
// It returns the following error codes: StatusMethodNotAllowed StatusNotFound StatusBadRequest
//
// To customize parsing and routing error handling of a particular ServeMux instance, use the
// WithProtoErrorHandler serve option.
//
// To customize parsing and routing error handling of all ServeMux instances not using the
// WithProtoErrorHandler serve option, set a custom function to this variable.
OtherErrorHandler = DefaultOtherErrorHandler
)
// MuxOrGlobalHTTPError uses the mux-configured error handler, falling back to GlobalErrorHandler.
func MuxOrGlobalHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, r *http.Request, err error) {
if mux.protoErrorHandler != nil {
mux.protoErrorHandler(ctx, mux, marshaler, w, r, err)
} else {
GlobalHTTPErrorHandler(ctx, mux, marshaler, w, r, err)
}
}
// DefaultHTTPError is the default implementation of HTTPError.
// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
// If otherwise, it replies with http.StatusInternalServerError.
//
// The response body returned by this function is a JSON object,
// which contains a member whose key is "error" and whose value is err.Error().
func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
const fallback = `{"error": "failed to marshal error message"}`
s, ok := status.FromError(err)
if !ok {
s = status.New(codes.Unknown, err.Error())
}
w.Header().Del("Trailer")
contentType := marshaler.ContentType()
// Check marshaler on run time in order to keep backwards compatibility
// An interface param needs to be added to the ContentType() function on
// the Marshal interface to be able to remove this check
if typeMarshaler, ok := marshaler.(contentTypeMarshaler); ok {
pb := s.Proto()
contentType = typeMarshaler.ContentTypeFromMessage(pb)
}
w.Header().Set("Content-Type", contentType)
body := &internal.Error{
Error: s.Message(),
Message: s.Message(),
Code: int32(s.Code()),
Details: s.Proto().GetDetails(),
}
buf, merr := marshaler.Marshal(body)
if merr != nil {
grpclog.Infof("Failed to marshal error message %q: %v", body, merr)
w.WriteHeader(http.StatusInternalServerError)
if _, err := io.WriteString(w, fallback); err != nil {
grpclog.Infof("Failed to write response: %v", err)
}
return
}
md, ok := ServerMetadataFromContext(ctx)
if !ok {
grpclog.Infof("Failed to extract ServerMetadata from context")
}
handleForwardResponseServerMetadata(w, mux, md)
handleForwardResponseTrailerHeader(w, md)
st := HTTPStatusFromCode(s.Code())
w.WriteHeader(st)
if _, err := w.Write(buf); err != nil {
grpclog.Infof("Failed to write response: %v", err)
}
handleForwardResponseTrailer(w, md)
}
// DefaultOtherErrorHandler is the default implementation of OtherErrorHandler.
// It simply writes a string representation of the given error into "w".
func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, msg string, code int) {
http.Error(w, msg, code)
}