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Add support for grpc error details
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When multiple errors are given, use details to encode errors into the
grpc status and decode details back into errors.

Signed-off-by: Derek McGowan <[email protected]>
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@dmcgowan
dmcgowan committed Jun 8, 2024
1 parent 038bb7b commit 2fd184b
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Showing 4 changed files with 295 additions and 59 deletions.
182 changes: 142 additions & 40 deletions errgrpc/grpc.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,12 +23,20 @@ package errgrpc

import (
"context"
"errors"
"fmt"
"reflect"
"strconv"
"strings"

spb "google.golang.org/genproto/googleapis/rpc/status"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/protoadapt"
"google.golang.org/protobuf/types/known/anypb"

"github.com/containerd/typeurl/v2"

"github.com/containerd/errdefs"
"github.com/containerd/errdefs/internal/cause"
Expand All @@ -47,47 +55,121 @@ func ToGRPC(err error) error {
return nil
}

if isGRPCError(err) {
if _, ok := status.FromError(err); ok {
// error has already been mapped to grpc
return err
}

s, extra := findStatus(err, "")
if s != nil {
var details []protoadapt.MessageV1

for _, e := range extra {
// Do not double encode proto messages, otherwise use Any
if pm, ok := e.(protoadapt.MessageV1); ok {
details = append(details, pm)
} else if pm, ok := e.(proto.Message); ok {
details = append(details, protoadapt.MessageV1Of(pm))
} else {

if reflect.TypeOf(e).Kind() == reflect.Ptr {
a, aerr := typeurl.MarshalAny(e)
if aerr == nil {
details = append(details, &anypb.Any{
TypeUrl: a.GetTypeUrl(),
Value: a.GetValue(),
})
continue
}
}
if gs, ok := status.FromError(ToGRPC(e)); ok {
details = append(details, gs.Proto())
}
// TODO: Else include unknown extra error type
}
}

if len(details) > 0 {
if ds, _ := s.WithDetails(details...); ds != nil {
s = ds
}
}
err = s.Err()
}

return err
}

// findStatus finds the first error which matches a GRPC status and returns
// any extra
func findStatus(err error, msg string) (*status.Status, []error) {
switch uerr := err.(type) {
case interface{ Unwrap() error }:
if msg == "" {
// preserve wrap message
msg = err.Error()
}
return findStatus(uerr.Unwrap(), msg)
case interface{ Unwrap() []error }:
var extra []error
var status *status.Status
for _, e := range uerr.Unwrap() {
// NOTE: Multi errors do not preserve message when created fmt.Errorf,
// Document this and suggest use of errors.Join with individual messages
// for each error.
s, errs := findStatus(e, msg)
if s != nil && status == nil {
status = s
extra = append(extra, errs...)
} else {
extra = append(extra, e)
}
}
return status, extra
}
if msg == "" {
msg = err.Error()
}

return getStatus(err, msg), nil
}

func getStatus(err error, msg string) *status.Status {
switch {
case errdefs.IsInvalidArgument(err):
return status.Error(codes.InvalidArgument, err.Error())
return status.New(codes.InvalidArgument, msg)
case errdefs.IsNotFound(err):
return status.Error(codes.NotFound, err.Error())
return status.New(codes.NotFound, msg)
case errdefs.IsAlreadyExists(err):
return status.Error(codes.AlreadyExists, err.Error())
return status.New(codes.AlreadyExists, msg)
case errdefs.IsFailedPrecondition(err) || errdefs.IsConflict(err) || errdefs.IsNotModified(err):
return status.Error(codes.FailedPrecondition, err.Error())
return status.New(codes.FailedPrecondition, msg)
case errdefs.IsUnavailable(err):
return status.Error(codes.Unavailable, err.Error())
return status.New(codes.Unavailable, msg)
case errdefs.IsNotImplemented(err):
return status.Error(codes.Unimplemented, err.Error())
return status.New(codes.Unimplemented, msg)
case errdefs.IsCanceled(err):
return status.Error(codes.Canceled, err.Error())
return status.New(codes.Canceled, msg)
case errdefs.IsDeadlineExceeded(err):
return status.Error(codes.DeadlineExceeded, err.Error())
return status.New(codes.DeadlineExceeded, msg)
case errdefs.IsUnauthorized(err):
return status.Error(codes.Unauthenticated, err.Error())
return status.New(codes.Unauthenticated, msg)
case errdefs.IsPermissionDenied(err):
return status.Error(codes.PermissionDenied, err.Error())
return status.New(codes.PermissionDenied, msg)
case errdefs.IsInternal(err):
return status.Error(codes.Internal, err.Error())
return status.New(codes.Internal, msg)
case errdefs.IsDataLoss(err):
return status.Error(codes.DataLoss, err.Error())
return status.New(codes.DataLoss, msg)
case errdefs.IsAborted(err):
return status.Error(codes.Aborted, err.Error())
return status.New(codes.Aborted, msg)
case errdefs.IsOutOfRange(err):
return status.Error(codes.OutOfRange, err.Error())
return status.New(codes.OutOfRange, msg)
case errdefs.IsResourceExhausted(err):
return status.Error(codes.ResourceExhausted, err.Error())
return status.New(codes.ResourceExhausted, msg)
case errdefs.IsUnknown(err):
return status.Error(codes.Unknown, err.Error())
return status.New(codes.Unknown, msg)
}

return err
return nil
}

// ToGRPCf maps the error to grpc error codes, assembling the formatting string
Expand All @@ -104,11 +186,25 @@ func ToNative(err error) error {
return nil
}

desc := errDesc(err)
s, isGRPC := status.FromError(err)

var (
desc string
code codes.Code
)

if isGRPC {
desc = s.Message()
code = s.Code()

} else {
desc = err.Error()
code = codes.Unknown
}

var cls error // divide these into error classes, becomes the cause

switch code(err) {
switch code {
case codes.InvalidArgument:
cls = errdefs.ErrInvalidArgument
case codes.AlreadyExists:
Expand Down Expand Up @@ -163,6 +259,31 @@ func ToNative(err error) error {
err = cls
}

if isGRPC {
errs := []error{err}
for _, a := range s.Details() {
if s, ok := a.(*spb.Status); ok {
errs = append(errs, ToNative(status.ErrorProto(s)))
} else if derr, ok := a.(error); ok {
errs = append(errs, derr)
} else if dany, ok := a.(typeurl.Any); ok {
i, uerr := typeurl.UnmarshalAny(dany)
if uerr == nil {
if derr, ok = i.(error); ok {
errs = append(errs, derr)
}
// TODO: Wrap unknown type in error for visibility
}
// TODO: Wrap unregistered type in error for visibility
}
// TODO: Wrap unknown type in error for visibility

}
if len(errs) > 1 {
err = errors.Join(errs...)
}
}

return err
}

Expand All @@ -179,22 +300,3 @@ func rebaseMessage(cls error, desc string) string {

return strings.TrimSuffix(desc, ": "+clss)
}

func isGRPCError(err error) bool {
_, ok := status.FromError(err)
return ok
}

func code(err error) codes.Code {
if s, ok := status.FromError(err); ok {
return s.Code()
}
return codes.Unknown
}

func errDesc(err error) string {
if s, ok := status.FromError(err); ok {
return s.Message()
}
return err.Error()
}
101 changes: 101 additions & 0 deletions errgrpc/grpc_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,11 +20,14 @@ import (
"context"
"errors"
"fmt"
"strings"
"testing"

"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"

"github.com/containerd/typeurl/v2"

"github.com/containerd/errdefs"
"github.com/containerd/errdefs/errhttp"
"github.com/containerd/errdefs/internal/cause"
Expand Down Expand Up @@ -172,3 +175,101 @@ func TestGRPCRoundTrip(t *testing.T) {
})
}
}

type TestError struct {
Value string `json:"value"`
}

func (*TestError) Error() string {
return "test error"
}

func TestGRPCCustomDetails(t *testing.T) {
typeurl.Register(&TestError{}, t.Name())
expected := &TestError{
Value: "test 1",
}

err := errors.Join(errdefs.ErrInternal, expected)
gerr := ToGRPC(err)

s, ok := status.FromError(gerr)
if !ok {
t.Fatalf("Not GRPC error: %v", gerr)
}
if s.Code() != codes.Internal {
t.Fatalf("Unexpectd GRPC code %v, expected %v", s.Code(), codes.Internal)
}

nerr := ToNative(gerr)
if !errors.Is(nerr, errdefs.ErrInternal) {
t.Fatalf("Expected internal error type, got %v", nerr)
}
if !errdefs.IsInternal(err) {
t.Fatalf("Expected internal error type, got %v", nerr)
}
terr := &TestError{}
if !errors.As(nerr, &terr) {
t.Fatalf("TestError not preserved, got %v", nerr)
} else if terr.Value != expected.Value {
t.Fatalf("Value not preserved, got %v", terr.Value)
}
}

func TestGRPCMultiError(t *testing.T) {
err := errors.Join(errdefs.ErrPermissionDenied, errdefs.ErrDataLoss, errdefs.ErrConflict, fmt.Errorf("Was not changed at all!: %w", errdefs.ErrNotModified))

checkError := func(err error) {
t.Helper()
if !errors.Is(err, errdefs.ErrPermissionDenied) {
t.Fatal("Not permission denied")
}
if !errors.Is(err, errdefs.ErrDataLoss) {
t.Fatal("Not data loss")
}
if !errors.Is(err, errdefs.ErrConflict) {
t.Fatal("Not conflict")
}
if !errors.Is(err, errdefs.ErrNotModified) {
t.Fatal("Not not modified")
}
if errors.Is(err, errdefs.ErrFailedPrecondition) {
t.Fatal("Should not be failed precondition")
}
if !strings.Contains(err.Error(), "Was not changed at all!") {
t.Fatalf("Not modified error message missing from:\n%v", err)
}
}
checkError(err)

terr := ToNative(ToGRPC(err))

checkError(terr)

// Try again with decoded error
checkError(ToNative(ToGRPC(terr)))
}

func TestGRPCNestedError(t *testing.T) {
multiErr := errors.Join(fmt.Errorf("First error: %w", errdefs.ErrNotFound), fmt.Errorf("Second error: %w", errdefs.ErrResourceExhausted))

checkError := func(err error) {
t.Helper()
if !errors.Is(err, errdefs.ErrNotFound) {
t.Fatal("Not not found")
}
if !errors.Is(err, errdefs.ErrResourceExhausted) {
t.Fatal("Not resource exhausted")
}
if errors.Is(err, errdefs.ErrFailedPrecondition) {
t.Fatal("Should not be failed precondition")
}
}
checkError(multiErr)

werr := fmt.Errorf("Wrapping the error: %w", multiErr)

checkError(werr)

checkError(ToNative(ToGRPC(werr)))
}
13 changes: 8 additions & 5 deletions go.mod
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,11 +2,14 @@ module github.com/containerd/errdefs

go 1.20

require google.golang.org/grpc v1.58.3
require (
github.com/containerd/typeurl/v2 v2.1.1
google.golang.org/genproto/googleapis/rpc v0.0.0-20240227224415-6ceb2ff114de
google.golang.org/grpc v1.63.2
google.golang.org/protobuf v1.33.0
)

require (
github.com/golang/protobuf v1.5.3 // indirect
golang.org/x/sys v0.13.0 // indirect
google.golang.org/genproto/googleapis/rpc v0.0.0-20231002182017-d307bd883b97 // indirect
google.golang.org/protobuf v1.31.0 // indirect
github.com/gogo/protobuf v1.3.2 // indirect
golang.org/x/sys v0.17.0 // indirect
)
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