prometheus/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go

71 lines
2.4 KiB
Go

package runtime
import (
"io"
"net/http"
"context"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/status"
)
// ProtoErrorHandlerFunc handles the error as a gRPC error generated via status package and replies to the request.
type ProtoErrorHandlerFunc func(context.Context, *ServeMux, Marshaler, http.ResponseWriter, *http.Request, error)
var _ ProtoErrorHandlerFunc = DefaultHTTPProtoErrorHandler
// DefaultHTTPProtoErrorHandler is an 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 Status message marshaled by a Marshaler.
//
// Do not set this function to HTTPError variable directly, use WithProtoErrorHandler option instead.
func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
// return Internal when Marshal failed
const fallback = `{"code": 13, "message": "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 compatability
// An interface param needs to be added to the ContentType() function on
// the Marshal interface to be able to remove this check
if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
pb := s.Proto()
contentType = httpBodyMarshaler.ContentTypeFromMessage(pb)
}
w.Header().Set("Content-Type", contentType)
buf, merr := marshaler.Marshal(s.Proto())
if merr != nil {
grpclog.Infof("Failed to marshal error message %q: %v", s.Proto(), 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)
}