status

README

Status

This is a convenience package for users of gogo/protobuf to be able to use their gogo/protobuf generated message easily and transparently with the gRPC status error structure.

It requires Go gRPC version 1.11 or above to successfully transmit statuses over the gRPC transport.

Use

Use as you would the normal grpc/status package:

return status.Error(codes.NotFound, "no such user")

st := status.New(codes.FailedPrecondition, "wrong user role")
detSt, err := st.WithDetails(&rpc.BadRequest{
    FieldViolations: []*rpc.BadRequest_FieldViolation{
        {
            Field:       "role",
            Description: "The first user created must have the role of an ADMIN",
        },
    },
})
if err == nil {
    return detSt.Err()
}
return st.Err()

License

The code is 95% copied from the official gRPC status package, so the gRPC License applies.

Changes

The changes applied include changing the use of the golang/protobuf packages to gogo/protobuf, and changing the generated files from google.golang.org/genproto/googleapis to github.com/gogo/googleapis/.

We've also created an implicit interface fulfilled by all gogo/status errors, for use with grpc/status and the gRPC runtime libraries.

Documentation

Overview

Package status implements errors returned by gRPC. These errors are serialized and transmitted on the wire between server and client, and allow for additional data to be transmitted via the Details field in the status proto. gRPC service handlers should return an error created by this package, and gRPC clients should expect a corresponding error to be returned from the RPC call.

This package upholds the invariants that a non-nil error may not contain an OK code, and an OK code must result in a nil error.

Index

• func Code(err error) codes.Code
• func Error(c codes.Code, msg string) error
• func ErrorProto(s *rpc.Status) error
• func Errorf(c codes.Code, format string, a ...interface{}) error
• type Status
  • func Convert(err error) *Status
  • func FromError(err error) (s *Status, ok bool)
  • func FromGRPCStatus(st *status.Status) *Status
  • func FromProto(s *rpc.Status) *Status
  • func New(c codes.Code, msg string) *Status
  • func Newf(c codes.Code, format string, a ...interface{}) *Status
  • func (s *Status) Code() codes.Code
  • func (s *Status) Details() []interface{}
  • func (s *Status) Err() error
  • func (s *Status) Message() string
  • func (s *Status) Proto() *rpc.Status
  • func (s *Status) WithDetails(details ...proto.Message) (*Status, error)

Functions

func Code

func Code(err error) codes.Code

Code returns the Code of the error if it is a Status error, codes.OK if err is nil, or codes.Unknown otherwise.

func Error

func Error(c codes.Code, msg string) error

Error returns an error representing c and msg. If c is OK, returns nil.

func ErrorProto

func ErrorProto(s *rpc.Status) error

ErrorProto returns an error representing s. If s.Code is OK, returns nil.

func Errorf

func Errorf(c codes.Code, format string, a ...interface{}) error

Errorf returns Error(c, fmt.Sprintf(format, a...)).

Types

type Status

type Status struct {
	// contains filtered or unexported fields
}

Status represents an RPC status code, message, and details. It is immutable and should be created with New, Newf, or FromProto.

func Convert

func Convert(err error) *Status

Convert is a convenience function which removes the need to handle the boolean return value from FromError.

func FromError

func FromError(err error) (s *Status, ok bool)

FromError returns a Status representing err if it was produced from this package or the standard grpc/status package. Otherwise, ok is false and a Status is returned with codes.Unknown and the original error message.

func FromGRPCStatus

func FromGRPCStatus(st *status.Status) *Status

FromGRPCStatus converts a grpc.Status to gogo.Status.

func FromProto

func FromProto(s *rpc.Status) *Status

FromProto returns a Status representing s.

func New

func New(c codes.Code, msg string) *Status

New returns a Status representing c and msg.

func Newf

func Newf(c codes.Code, format string, a ...interface{}) *Status

Newf returns New(c, fmt.Sprintf(format, a...)).

func (*Status) Code

func (s *Status) Code() codes.Code

Code returns the status code contained in s.

func (*Status) Details

func (s *Status) Details() []interface{}

Details returns a slice of details messages attached to the status. If a detail cannot be decoded, the error is returned in place of the detail.

func (*Status) Err

func (s *Status) Err() error

Err returns an immutable error representing s; returns nil if s.Code() is OK.

func (*Status) Message

func (s *Status) Message() string

Message returns the message contained in s.

func (*Status) Proto

func (s *Status) Proto() *rpc.Status

Proto returns s's status as an rpc.Status proto message.

func (*Status) WithDetails

func (s *Status) WithDetails(details ...proto.Message) (*Status, error)

WithDetails returns a new status with the provided details messages appended to the status. If any errors are encountered, it returns nil and the first error encountered.