Behaviour Change: transport errors should be coded Unavailable instead of internal. (#1307)

go16.go

@@ -56,7 +56,7 @@ func toRPCErr(err error) error {
 	case transport.StreamError:
 		return status.Error(e.Code, e.Desc)
 	case transport.ConnectionError:
-		return status.Error(codes.Internal, e.Desc)
+		return status.Error(codes.Unavailable, e.Desc)
 	default:
 		switch err {
 		case context.DeadlineExceeded:

go17.go

@@ -56,7 +56,7 @@ func toRPCErr(err error) error {
 	case transport.StreamError:
 		return status.Error(e.Code, e.Desc)
 	case transport.ConnectionError:
-		return status.Error(codes.Internal, e.Desc)
+		return status.Error(codes.Unavailable, e.Desc)
 	default:
 		switch err {
 		case context.DeadlineExceeded, netctx.DeadlineExceeded:

rpc_util_test.go

@@ -148,7 +148,7 @@ func TestToRPCErr(t *testing.T) {
 		errOut error
 	}{
 		{transport.StreamError{Code: codes.Unknown, Desc: ""}, status.Error(codes.Unknown, "")},
-		{transport.ErrConnClosing, status.Error(codes.Internal, transport.ErrConnClosing.Desc)},
+		{transport.ErrConnClosing, status.Error(codes.Unavailable, transport.ErrConnClosing.Desc)},
 	} {
 		err := toRPCErr(test.errIn)
 		if _, ok := status.FromError(err); !ok {